installation, commissioning, service & user …...room sealed unit heaters installation,...

Room Sealed Unit Heaters

Installation, Commissioning,Service & User Instructions

ModelsFRSA, FRSB,

FRSC & FRSD75 - 210

August 2000Part No. X224B

ROOM SEALED UNIT HEATERS

These appliances have been tested and certified as complying with the essentialrequirements of the Gas Appliance directive, The low voltage directive ,TheElectromagnetic Compatibility Directive and the Machinery Directive for use on naturalgas and L.P.G gas when installed , commissioned and maintained in accordance withthese instructions.

These instructions refer to appliances designed to operate in the following countries...Ireland (IE), Spain (ES), Italy (IT) & United Kingdom (GB)Appliances designed for other countries are available on request.

These appliances are Cat II 2 H 3+

appliances for use with natural gas (G20) or L.P.G.(G31 / G30) as stated on the heater data plate, and are intended for indoor installationonly.

For GB and IE They are type C32 appliances for vertical flue terminals andtype C 12 for horizontal flue terminals.For use in ES and IT they are Type C32 appliances for connecting to suitableapproved sealed combustion air and flue systems.

This Appliance must be installed in accordance with the rules in force and used onlyin a sufficiently ventilated space, as specified in these instructions.

Before installation, check that the local distribution conditions, nature of gas andpressure, and adjustment of the appliance are compatible.


ContentsThe parts of this manual are numbered by section, clause and sub clause. Hence 1:2:3 refers to section Iclause 2 sub clause 3. Figure numbers also follow this notation. Hence Fig. 2:3 is section 2 Fig. 3.

Section

1. General Specification

2. Technical Data

3. Heater Installation

4. Commissioning of the Air Heater

5. Wiring Diagram

6. Servicing Instructions

7. Removal and Replacement of Parts

8. Fault Finding Charts

9. User Instructions

10. Conversion between Natural gas and L.P.G.

11. Parts List

12. Commissioning Data Sheet

THIS AIR HEATER IS FOR USE WITH NATURAL GAS OR L.P.G. AS STATED ON THE HEATER DATAPLATE

THESE INSTRUCTIONS ARE TO BE LEFT WITH THE USER OR NEAR THE HEATER

NOTE: Every effort is made to ensure the information within this manual is accurate. However, Roberts-Gordonreserves the right to alter specifications without prior notice.

Roberts-Gordon shall not be liable to rectify any defects or damage caused by any modifications made orattempted to be made to the heating units by the customer, his servants, agents or employees.

WARRANTY The Heat Exchanger has a ten year Warranty (subject to terms and conditions).


Section 1. General Specification1.1 Basic Information

COMBAT® FRSA, FRSB, FRSC & FRSD ranges of unit air heaters are type C32 appliances for vertical flueterminals and C12 for horizontal flue terminals both of which have room sealed combustion and fan assistedflues. They are designed to be suspended or shelf mounted, and are produced in an 8 size range from 27 kW(92,124 Btu/hr) to 76 kW (259,312 Btu/hr) heat input (Gross CV).

Heaters must be installed in accordance with local regulations and the requirements of Section 3 of theseInstructions.

A permanent electrical supply of 230 volts 50 Hz, single phase is required for all models and all models mustbe earthed.

ON/OFF, temperature and time control may be obtained by use of CC1/A control consoles (obtainable fromRoberts-Gordon.) or by the use of individual controls as per the circuit diagrams in Section 5.

The FRSA range of heaters are fitted with quiet running axial fans.

The FRSB range of heaters are fitted with Direct Drive centrifugal fan blowers to allow them to be fitted toduct distribution systems ,when supplied with the factory fitted outlet spigot.

The FRSC range of heaters are the same specification as the FRSB range, but are fitted with an enclosure forthe main fans to allow inlet ducting to be fitted.

The FRSD range are sold without a fan unit to be installed onto the customers ducting and air moving system.

1.2 Heater Operation

COMBAT® FRSA, FRSB, FRSC & FRSD warm air heaters are supplied ready for installation on site. Theyare fitted with an automatic ignition control which ignites the gas and monitors for the safe operation of theburner each time the external controls call for the heater to operate.

When the external controls call for heat, the automatic control operates the flue fan and burner, to supply heatto the heat exchanger. After approximately 2 or 3 minutes the air delivery fan will start to run, supplying warmair to the building.

When the external controls are satisfied they will turn off the burner leaving the fan running to cool down theheat exchanger. When cool enough the fan thermostat will turn off the fan.


Fig. 1.1 General Arrangement - FRSA Models

WARNING:The main electrical isolator should only be used in an emergency and should not be used forclosing down the burner, as this switches off the main fan prematurely and may damage the

heat exchanger.Such action may cause a fire hazard and invalidate the warranty .

Mounting Brackets

Flue Pipe (front) Air Intake Pipe (rear)Gas Pipe Connection

Outlet Grille withAdjustable Louvres

Main Fanon RearPanel

Lock fordoor

Electrical entryand SecondLimit Stat onRear

Lockout Reset Button

Lighting Instructions

Warning Lights:GREEN - Burner OnRED - Lockout

Data Plate

Dimension Data (see Figs.1.2 to 1.4 - Dimension Diagrams)

Model

'A' - Width

'B' - Width between hanging points

'C' - Flue/Air Intake Diameter

'D'

'E'

'F'

'G' - Inlet/Outlet Duct Spigot Width

Weight - FRSA

Weight - FRSB

Weight - FRSC

Weight - FRSD

95

775

296

100

140

192

117

508

113

118

136

105

105

775

296

100

140

192

117

508

115

129

147

115

120

915

436

100

140

192

117

648

128

140

159

128

135

915

436

130

225

168

132

648

138

152

171

138

150

1055

576

130

225

168

132

788

150

163

184

150

170

1055

576

130

225

168

132

788

154

178

199

154

210

1195

716

130

225

168

132

928

174

200

223

174

75

705

226

100

140

192

117

438

105

110

127

97

mm

mm

mm

mm

mm

mm

mm

kg

kg

kg

kg


Fig. 1.2 Front View DimensionAll FRS Models*

Fig.1.3 Plan ViewAll FRS Models (Shown without main fan)

Fig.1.4 Side View Dimensions

FRSC

* Note:FRSD models are fitted with an air outlet spigot as standard. All inlet and outlet duct spigots are complete with 25mm mez. flange.

140 510 (Centres)

751 680

1431

674

x G

(W

idth

)23

4

FRSD

495

x G

(Wid

th)

234

495

x G

(Wid

th)

234

7511051

150 150

140 510 (Centres)

140 510 Centres

751

837

FRSA FRSB140 510 Centres

751

1211 (except Models 150 & 170: 1177)

240 240B Centres

A

990

Gas Connection

C (Air Intake)

C (Flue)

5255

103

Rear

ED

F FrontHanging Points


Not

e: f

or F

RS

D d

ucte

d un

its s

old

with

out

fans

, th

e ai

r flo

w p

rovi

ded

by t

he s

yste

m m

ust

be a

ble

to p

rodu

ce a

t le

ast

the

low

er o

f th

e ai

r flo

ws

of t

he F

RS

A o

r th

e F

RS

B h

eate

rof

the

sam

e m

odel

.

Technical Data - General Data for all FRS... Range

TAB

LE

2.1

GE

NE

RA

L D

ATA

LE

DO

M57

59501

021531

051071

012

SE

VLA

VS

AG

NIA

ME

PY

T&

RE

BM

UN

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

avoN.T.I.

S711.228.0

FF

O1

EZIS

NOI

TC

EN

NO

CS

AG

4/3R

4/3R

4/3R

4/3R

4/3R

4/3R

4/3R

4/3R

EP

YT

NAF

EU

LF

NIR

OT61467

OU

ANI

ROT

61467O

UA

NIR

OT61467

OU

ANI

ROT

61467O

UA

NIR

OT61467

OU

ANI

ROT

52157O

UA

NIR

OT52157

OU

ANI

ROT

52157O

UA

.qs

mm

EZIS

ECI

FIR

OE

UL

F05.43

05.0407.14

05.4402.84

00.6494

45

NAF

LAI

XA

-S

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ED

NAF

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DA

OL

LA

CIR

TC

LE

LAT

OT

352352

092092

605605

644644

RO

TO

MN

AFNI

AM

v032w071

v032w071

v032W012

v032W012

v032W081

v032W081

v032w071

x2

v032w071

x2

)sp

mA(

TN

ER

RU

CG

NIN

NU

RR

OT

OM

07.007.0

68.068.0

8.18.1

45.145.1

TN

ER

RU

CT

RAT

SR

OT

OM

09.109.1

03.203.2

4.34.3

2.42.4

EP

YT

NAF

NIA

M&

DE

TTI

FR

EB

MU

N

GM

Pnafi

S101-14053

1

GM

Pnafi

S101-14053

1

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1

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S101-14093

1

GM

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S101-14024

1

GM

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S101-14024

1

GM

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S101-14053

2

GM

Pnafi

S101-14053

2

Fµ

EZIS

RO

TIC

AP

AC

5.25.2

33

55

5.2x

25.2

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mW

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FRI

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nim/³tf(

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0063)9112(

0663)4512(

0093)5922(

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)a(B

dR

Nm3

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RE

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N06

0600.16

00.1646

1600.56

00.46

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LA

GU

FIR

TN

EC

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LIAT

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NAF

sttaW

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v032W055

x2

v032W055

x2

TN

ER

RU

CG

NIN

NU

RR

OT

OM

9.32.5

2.51.5

1.55.7

4.93.01

TN

ER

RU

CT

RAT

SR

OT

OM

8.44.6

4.60.6

0.63.9

6.118.21

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bm

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deeps

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sm

umixa

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4.116.31

pm

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00.8600.66

00.07

Section 2. Technical Data


L.P.

G.

II2H

3+

II2 H

3+

G20

H G

AS

TAB

LE

2.2

BU

RN

ER

DA

TA

LE

DO

M57

59501

021531

051071

012

VC

SS

OR

GT

UP

NIT

AE

HWk

rh/utB

7242129

43800611

5.83263131

00.44821051

05.94498861

5.45459581

5.16838902

00.67213952

VC

TE

NT

UP

NIT

AE

HWk

rh/utB

13.425.55928

26.035.264401

76.434.882811

26.937.681531

5.44580251

80.94744761

83.55459881

4.86405332

TU

PT

UO

TA

EH

Wkrh/ut

B47.1206147

73.7268339

99.03647501

24.53358021

58.93069531

78.34396941

15.94029861

81.16647802

)S

AG

LA

RU

TA

NK

U(02

GE

TA

RS

AG

h/3m

rh/3tf75.268.09

42.314.411

76.365.921

91.460.841

27.475.661

91.54.381

68.559.602

42.757.552

)S

AG

LA

RU

TA

NK

U(02

GE

RU

SS

ER

PR

EN

RU

Brab

mG

Wsni

9.3185.5

5.4128.5

8.2141.5

5.2120.5

8.2141.5

9.1187.4

1.2168.4

0.3122.5

EZIS

SR

OT

CEJ

NIR

EN

RU

BNI

AM

FF

OR

EB

MU

NG

NIK

RA

MD

NA

49.0x

54

495

49.0x

55 495

49.0x

56 495

49.0x

57 495

49.0x

58 495

49.0x

59 495

49.0x

501495

49.0x

521495

HC

TIW

SG

NIV

OR

PE

UL

FR

OF

GNI

TT

ES

rabm

01.101.1

01.101.1

01.107.1

07.107.1

LE

DO

M57

59501

021531

051071

012

VC

SS

OR

GT

UP

NIT

AE

HWk

rh/utB

5.5260078

00.13277501

5.73059721

00.44821051

5.94498861

5.45459581

5.16838902

67213952

VC

TE

NT

UP

NIT

AE

HWk

rh/utB

64.3274008

25.8221379

5.437177111

84.04121831

45.54683551

41.05280171

85.65550391

29.96275832

TU

PT

UO

TA

EH

Wkrh/ut

B66.0257407

11.5257658

83.03046301

46.53406121

1.04408631

51.44326051

28.94969961

65.16340012

EN

AP

OR

P13

GE

TA

RS

AG

h/3m

h/gkh/l

ediuqil

69.087.1

5.3

71.161.2

2.4

14.116.2

1.5

66.170.3

0.6

68.154.3

8.6

50.28.34.7

13.292.44.8

68.23.54.01

EN

AP

OR

P13

GE

RU

SS

ER

PR

EN

RU

Bsrab

mG

Wsni

0.6354.41

08.5373.41

07.5333.41

08.5373.41

04.5312.41

03.5371.41

02.5331.41

06.5379.41

EN

ATU

B03

GE

TA

RS

AG

h/3m

h/gkh/l

ediuqil

37.087.11.3

98.061.2

8.3

70.126.2

6.4

62.170.3

4.5

24.154.3

0.6

65.18.36.6

67.192.45.7

71.23.52.9

EN

ATU

B03

GE

RU

SS

ER

PR

EN

RU

Bsrab

mG

Wsni

00.8242.11

01.8282.11

9.7202.11

09.722.11

08.7261.11

05.7240.11

04.720.11

02.8223.11

EZIS

SR

OT

CEJ

NIR

EN

RU

BNI

AM

FF

OR

EB

MU

NG

NIK

RA

MD

NA

45.0x

64 45

45.0x

65 45

45.0x

66 45

45.0x

67 45

45.0x

68 45

45.0x

69 45

45.0x

601 45

45.0x

621 45

HC

TIW

SG

NIV

OR

PE

UL

FR

OF

GNI

TT

ES

srabm

01.101.1

01.101.1

01.107.1

07.107.1

App

lianc

e C

ateg

ory

II 2

H3+

Pro

pane

Gas

Inl

et p

ress

ure

37

mba

r (2

5 -

45)

Nat

ural

gas

inle

t pr

essu

re 2

0 m

bar

(17

- 25

)B

utan

e ga

s In

let

pres

sure

29

mba

r (2

0 -

35)


2.1 Gas Controls

The heaters will be fitted with S.I.T Nova gas control valves.

Main Gas Control Valve - Natural GasThe multifunctional main gas valve contains two automatic shut off valves. When set up as defined in Section4 the valves will have a step or slow opening operation on the main gas, to give smooth lighting. Settings ofthe valves are given in Section 4 and tables in Section 2.

Main Gas Control Valve - L.P.G.The Multifunctional main valve is tha same as used for natural gas (see Section 10, "Conversion BetwenGasses"), but with the Pressure regulator put out of action.

2.2 Main Fan

The main air moving fan/s fitted to these heaters are operated automatically by the fan thermostat within theHoneywell combination fan/limit thermostat. When suitably connected to site wiring (see Section 5) the fan/smay also be operated manually to distribute unheated air.

2.3 Limit Thermostats

There are two limit thermostats on these heaters to protect them from overheating, should the fan fail for anyreason.

One is within the Honeywell combination thermostat and the second one being situated on the rear of theheater.

2.3.1 Honeywell Combination Fan/Limit Thermostat

The combination fan/limit thermostat is a dual function control and safety device (see Fig. 2.4). There are twofitted to FRSD ducted heaters, the extra one being fitted at the rear inlet spigot.

Fan ThermostatThe fan thermostat controls the operation of the main fan during the heater operating cycle and ensures thatunprogrammed cold air is not circulated. This control also ensures that the main fan continues to run after theburner turns off to dissipate the residual heat from the heat exchanger.

The white button on the fan thermostat should be pulled to its “out” position for normal operation. In the“pushed in” position the fan will run continuously. However, when connected to suitable site wiring this featuremay be catered for by the remote fan on facility of remote controls.

Limit ThermostatThe limit thermostat operates in overheat conditions caused by insufficient air passing over the heatexchanger. This is a manual reset device and is reset by pressing in the red button on the thermostat. Note:the heat exchanger must have cooled to below the operating temperature for reset to be possible.

2.3.2 Second Limit Thermostat

This is a preset, manual reset device and is designed to be fail safe (see Figs. 1.1 & 1.2).

To reset this thermostat:

a) Remove the screw on cover of the thermostat where it protrudes from the mounting plate.

b) Push in the Black button in the centre of the thermostat, (note the heat exchanger must be cooled to allowthis to happen).

c) Replace the cover.


Fig. 2.4 Combination Fan/Limit Thermostat

WARNING: IT IS ESSENTIAL THAT THE BREAK OFF LINK SHOWN ISREMOVED IN THE EVENT OF THERMOSTAT REPLACEMENT

Fig. 2.5 Satronic DMG 970 MOD 03 Control Box Sequence


2.4 Burner Control Box

2.4.1 Description (DMG 970 MOD 03 CONTROL BOX)

The fully automatic gas burner fitted to all models is controlled by a Satronic DMG 970 MOD 03 plug-in controlbox. This control ensures the safe start and stop sequence and also monitors the safe presence of a flameand operation of the flue fan.

2.4.2 Sequence of Events

With the external controls on and calling for heat, and the flue proving air pressure switch at rest (contactsopen), the flue fan will switch on after a 5 second wait.

Note: If the air pressure switch contacts are closed there will be no start.

2.4.3 Air Pressure Switch Contacts

With the flue fan now running, the air pressure switch contacts have to close within the next 10-15 seconds toindicate the availability of sufficient combustion air or lockout will occur.

2.4.4 Purge

The sequence continues with a purge time with just the flue fan running.

2.4.5 Electric Ignition ON

The electric ignition switches ON at the end of this purge time.

2.4.6 Main Gas Valve

As these appliances are designed for direct main flame ignition ,the main gas valve opens and once a flamehas been established this remains on until close down. The flame probe is now continuously monitoring for thesafe presence of flame.

2.4.7 Electric Ignition OFF

Five seconds later the electric ignition turns off, leaving the flame to be proved as stable.

2.4.8 Close Down

When the external controls are satisfied the control box turns off all outputs simultaneously and returns to restposition for the beginning of the next sequence.

2.4.9 Fault Conditions

If at any stage the flame fails or the air pressure switch detects a loss of air pressure, the control will go to‘lockout’. The red light will glow and the control will need to be manually reset (either at the conrol or at aremote reset button ,if installed) before any further start attempt can be made.

Minimum flame probe current 1 ,mA . DC.Typical flame probe current 3-5 ,mA . DC.

2.5 Flue Proving (Air Pressure Switch)

This device, which is housed inside the controls compartment at the side of the heater, monitors the flow offlue products produced by the flue fan. It is factory set and the correct one must be fitted for the model (seeSection 4 and Data Tables in Section 2).


Section 3. Heater Installation3.1 Required Standards

It is important that all gas appliances are installed by competent persons, in accordance with the relevantrequirements of the local laws and regulations. Failure to install gas appliances correctly could lead toprosecution.

THE RELEVANT REGULATIONS ARE .......

Gas Safety (Installations and use) Regulations 1984.

BS 6230 Specification for the Installation of Gas Fired Forced Convection Air Heaters forCommercial and Industrial Space Heating of Rated input Exceeding 60kW.

BS 6891 Low Pressure Installation Pipes or Institute of Gas Engineers Document IGE/UP/2.

BS 5588 Parts 2 and 3 Fire Precautions In the Design and Construction of Buildings.

The Building Regulations ; The I.E.E Regulations ; The Health and Safety at Work etc Acts ; AnyRequirements of the Local Authority, Fire Officer and Insurance Company

The installation will be similar to the one shown in Figure 3.1.

3.2 General

All models must be installed with the base level and may be suspended from a ceiling or specially preparedwall brackets of sufficient strength to adequately support the weight of the heater as listed in Section 2. DataTables. All heaters may be mounted on a NON combustible shelf. Drop rods should be a minimum of 12 mmdiameter mild steel. The four hanging brackets are located on top of the heater, for all models.

They will normally be installed at between 2.75m and 3.75m above the floor.

Clearances around the heater as indicated in Fig. 3. 1 must be maintained to ensure adequate access forservicing and to ensure that the temperature of combustible materials does not exceed 65°C.

Note: for servicing, the burner is removed only from the right hand side of the heater as viewed from the front.Adequate clearance of at least the total width of the heater, or 0.8m which ever is greater, will be required onthis side between the heater and any obstruction to allow burner removal.

It is important to ensure that at all times there is adequate air circulation around the heater to supply air forboth ventilation and distribution.

Consideration should also be given when siting a heater to allow for the proper location of the flue and airintake pipes.

It is important that the gas supply pipe and the electrical connections do not support any of the heater'sweight.

WARNING:AIR HEATERS SHOULD NOT BE INSTALLED IN CORROSIVE ATMOSPHERES i.e. NEAR PLATING

OR DEGREASING PLANTS OR IN AREAS WHERE THERE IS A FIRE RISK.CONSULT LOCAL REGULATIONS FOR FURTHER INFORMATION ON HAZARDOUS AREAS.


3.3 Gas Supply General

The installation must comply with local laws and regulations, and the complete installation including the metermust be purged and tested for soundness.

The gas supply must be via metal pipes and terminate at the heater with a manual gas valve of the 90º turntype and union as in Fig. 3.1 to facilitate servicing.

The gas supply pipes must be sized to supply the correct amount of gas to the heater inlet at the specifiedinlet pressure under all load conditions. The pressure test point for measuring the inlet gas pressure issituated at the top of the heater near to the connection point.

On suspended heaters it is recommended that an approved metal flexible connection is used between themanual valve and the heater.

Note: due to the design of flexible connectors it is usually needed to use at least one pipe size larger than thesupply gas pipe to reduce the pressure loss through the connector.

Natural GasThe gas meter and service must be checked by the local gas supply undertaking to ensure that it is adequateto deal with the total connected load of the completed installation.

The maximum inlet pressure for natural gas is 25 mbar.

L.P.G.For L.P.G. applications each heater must be provided with gas having the inlet pressure closely controlled to37 mbar for Propane (G31) or 29 mbar for Butane (G30). This is best provided by the installation of a suitableregulator controlling the inlet to each heater so as to ensure that variations in system pressure are nottransferred to the individual heaters.

The maximum inlet pressure for LPG is 45 mbar for Propane or 35 mbar for Butane.

3.4 Flue and Combustion Air Intake

Each heater must be fitted with airtight sealed flue and combustion air intake pipes of the correct size to fitinto the provided spigots and as supplied by Roberts-Gordon. These must be within the maximum lengthstated in the Data Table on Fig. 3.1 and terminate with the special concentric balanced flue terminal into theopen air. The pipe sections must be assembled ensuring that each section seals correctly into the next.It is most important that the maximum flue and inlet pipe resistance is not exceeded. As a guide forestimating resistance each 90° of bend shortens the maximum flue and air intake length by 1m.

If the flue passes through a wall or ceiling of combustible material it must be enclosed by a sleeve ofnoncombustible material and separated from the sleeve by at least 25 mm air gap. The temperature of anycombustible material near the flue or heater must not exceed 65°C when the heater is in operation.

The flue must be at least 50 mm from any other combustible material.

The joints between the flue and the roof or wall must be made good to prevent water ingress.

The flue and air intake pipes should be installed and supported so that the unit heater does not carry theweight. The final section through the wall or roof must be the concentric balanced flue terminal connected withthe flue to the inside duct and the combustion air to the outside duct (see Figure 3.1).

There are two types of concentric terminal available, one for vertical mounting through the roof and one forhorizontal mounting through a wall.

The flue pipe must always be the inner pipe of the concentric flue terminal and must be installed in positionswhich will not cause the products of combustion to be drawn back into the building through open doors,windows or ventilation systems.


3.5 Air Supply

As these heaters are of room sealed design there is no need to provide a separate air supply for combustion,however provision must be made for the main distribution air and for ventilation particularly when the heater isinstalled in a plant room where the ambient temperature must be maintained below 32°C at all times.

3.5.1 Building Ventilation

Air shall be taken from an outside point where it is not likely to be contaminated, for example with smells,road vehicle exhausts, dry cleaners, exhausts, solvents, etc.

The minimum quantity of outside air required for ventilation shall be at least that required for personnel withinthe building.

3.6 Electrical Supply

The electrical installation must be carried out by a qualified electrician in accordance with the local regulationsusing the Wiring Diagrams in Section 5.

THE HEATER AND ITS CONTROLS MUST BE PROPERLY EARTHED.

A constant 230 v 50 Hz single phase supply is required for all models which must be connected into the mainterminals as shown in Section 5.

For the correct operation of the burner control box it is essential that the electrical supply has the earth andneutral wires at the same potential and that the supply is only connected to the correct terminals of the heaterE, N, L, in the connection block on the side of the heater as shown in Section 5.

The final connection to the heater should be in metal sleeved flexible cable, or flexible conduit, to the terminalblock. Cable size should be 1 sq.mm. Reusable cable ties are provided at the lower edge of the controls panelinside the heater to ensure that site connecting cables are installed tidily and do not impede the removal ofthe burner tray.

It is recommended that the length of the final connecting wires to the live terminal is shorter than the wires tothe Neutral or Earth so that in the event of the cable being pulled out of the terminals the Live will disconnectfirst.

An isolator with a contact separation of at least 3 mm on all poles should be installed adjacent to the heaterand/or the control panel, to disconnect all supplies to the heater (see Section 5).

A fuse size of 5 amps must be used on all FRSA models and 10 amps or 15 amp fuses must be used onFRSB models dependant on model size. FRSD heaters will require a 5 amp fuse for the heater and suitableconnection to the duct fan system in accordance with Section 5 and local regulations.

3.6.1 Remote Controls

The heaters are designed to be operated by controls installed remote from the heater. Any control intended tooperate the burner must have contacts that are free of voltage from external sources which are connectedbetween terminals 2 & 3 of the main terminal block on the side of the heater. The contacts will make toenergise the burner.

Burner ControlsThe minimum control scheme must have a room thermostat.


Fan ControlsThe main fan is designed to operate automatically providing there is a constant 230v supply to the mainterminals. However a switch, free of voltage from external sources, wired between terminals L & 1 in the mainterminal block at the side of the heater will provide for summer running of the fan.It is acceptable for the fan to operate continuously from external control, with the burner cycling on and offproviding that the fan run on at close down is not impaired.

3.6.2 Siting of Control Consoles or Room Thermostats

The Roberts-Gordon® control console or room thermostat should be mounted on a wall or column at a heightof approximately 1.5 metres from the floor of the building being heated. It is important for both comfort and fueleconomy that the control or thermostat is sited where it will monitor an average room temperature i.e. keepclear of cold draughts from doors, windows etc., similarly it should be kept out of the direct path of warm airfrom the heater. Areas of little air movement e.g. corners, should also be avoided.

3.7 FRSB Heaters, Distribution Ductwork and FRSD Heaters

3.7.1 FRSB Heaters

FRSB heaters are supplied with three speed direct drive centrifugal fans which have been connected tooperate with the heater free blowing into the heated space. Each of the fans has built in thermal overloadprotection.The data tables will indicate the normal number of fans and their standard running speed for each model .It is essential that the fans are not operated at higher speeds than the original setting on the heater withoutprior consultation with Roberts-Gordon. Such action may cause the fan motors to be overloaded.Overloading the motor will cause the built in thermal overload protection device to operate.

If the heaters are to be connected to a duct distribution system then they must be specified to befactory fitted with an outlet spigot as described below in 3.7.2.

Where two fans are fitted these will be switched using a fan contactor built into the heater see the wiringdiagrams in section 5The three speed winding connections are:

Low speed White Neutral, Red Live. The other two windings are "parked" separately inspare terminals

Medium speed White Neutral, Blue live. The other two windings are "parked" separately in spareterminals

High speed White Neutral, Black live. The other two windings are "parked" separately inspare terminals

FRSC heaters are FRSB heaters supplied with an inlet spigot to encase the fans and provide for connectingto an inlet duct system.


3.7.2 Distribution Ductwork

It is important when ducted systems are required that only FRSB, FRSC or FRSD models are selected andthat the inlet and/or outlet flanges made and fitted at the factory are used at the heater to ensure that theintegrity of the sealed combustion zone is not impaired.

Provision should be made so that the complete heater may be removed from the duct system.

It is recommended that flexible duct connectors are used to reduce duct bourne noises.

The cross sectional dimensions of the connecting ducts must be maintained to those of the heater spigot forat least twice the major spigot dimensions. This should ensure that adequate air flow will pass over the wholeof the heat exchanger cross sectional area.

All joints between the heater and the ductwork should be made as air tight as possible.

When installing a heater onto ducting it is possible for the duct installation to change the natural convected airflow through the heater before the fan is turned on. Under these condition it is sound practice to use anelectrical design (such as a 60 second time delay relay - see Section 5) to force the fan to run and not rely onthe fan thermostat to turn it on. Any such device must be in parallel with the fan thermostat so that the fan runon operation will still take place. FRSD models have two combination thermostats, with the extra one fitted atthe rear inlet spigot to cater for this effect.

Contact Roberts-Gordon design department for advice regarding duct resistance and design.

3.7.2 FRSD Heaters

For FRSD heaters it is essential that the airflow in the duct system is at least that specified in the DataSheets in Section 2 and in the correct direction across the heat exchanger as indicated by the arrow on theheater. Higher air flows are acceptable but it should be remembered that as the air flow rises the temperaturerise across the heat exchanger will fall.

It is recommended that the fan is positioned to blow the air through the heat exchanger.

It is important that the duct is designed as described in 3.7.1. above to ensure that there is a homogenous airflow across the whole of the heat exchanger.

Failure to provide a suitable air flow properly distributed across the heat exchanger will cause heat exchangerfailures

The fan motor or its control should contain a method of overload protection and be supplied via a localelectrical isolator if it is installed remote from the heater. Where such a local isolator is installed it should bepositioned and labelled to prevent inadvertent operation


SealedJoints

M12 Hanging Points

3m Clearance

Clearance at sideat least 0.8m

Clearance at rear at least 0.6m from rear offan

Maximum Flue Length 8m straight (see textfor reducing length for bends etc.

Union Fitting

Isolating Gas Valve

Electrical Entry on rear panelMinimum Clearance at this side, forburner removal - heater width or 0.8m,whichever is greater

Gas Supply

Clearance from floor:2.75m to 3m for FRSA2.75m to 3.75m for FRSB

Special Concentric Terminal -Horizontal and Vertical VersionsAvailable

Clearance above heater fromcombustible material: 0.6m

Air Intake Pipe

Flue Pipe

Fig. 3.1 Typical Heater Installation for FRSA, FRSB, FRSC & FRSD

All clearances and distances in metres for the installation

Detail of Flue Components

* The maximum length of flue and air intake pipes must not be exceeded. The effect of bends etc. must be taken into consideration and the total length of pipe reduced accordingly

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Section 4. Commissioning the HeaterBefore starting to commission a heater read this section through and fully understand it's contents.Only competent engineers should carry out the work.

Checks before lighting the unit heater

4.1 Pre-Commission Checks

Ensure that the heater and all controls are suitable for the gas, pressure and electrical supply that they arebeing connected to.

4.1.1 Electrical Check

A preliminary electrical check should be carried out by a qualified engineer, after completion of the installationand before commissioning the heater as follows:-

Check that all site wiring is connected in accordance with the appropriate wiring diagram of Section 5.

4.1.1.1

Check the correct fuse size is fitted, 5 amp for FRSA heaters and 10 amp or 15 amp (depending on model) forFRSB or FRSC heaters. This must be connected in the live conductor, (see 4.1.1.4 below).

4.1.1.2

The appliance earthing must be tested using a suitable method according to local regulations. The resistanceof the earth circuit from the heater to the earth connection must be 0.1 ohm or less.

4.1.1.3

Connect one lead of a suitable voltmeter to earth and connect the other lead to the live supply terminal at theheater.

Turn on power to heater. A reading of approximately 230 volts should be given.

4.1.1.4

The same result should be obtained by connecting the test leads from live to neutral.

Connecting the voltmeter between Neutral ‘N’ and Earth should give a reading of0 volts. If these tests do not conform to the above there is a fault which must be rectified before progressingfurther with the commission. An electrician should be consulted to carry out this work.

4.1.2 Flue Proving Switch Setting

The setting of the air pressure switch that proves the correct flow of air in the flue system is factory presetand must not be adjusted. For checking that the device is operating correctly see Section 7.9.Only pressure switches that have been calibrated by Roberts-Gordon for use on the specific model of heatermay be used.


4.2 Gas Supply

The whole of the gas installation, including the meter, should be inspected, tested for soundness and purgedin accordance with local regulations.

It will be necessary to ensure that the air is fully purged from the heater inlet pipe up to the main gas valveinlet test nipple before the gas burner will ignite.The pressure test point for measuring the inlet gas pressure is situated at the top of the heater near to theconnection point.

4.3 Mechanical Checks

1. Check that the fan is free to run and delivery louvres are turned to give required air deflection.

2. Check that the flue and combustion air pipes are installed in accordance with these instructions and localregulations.Note: the inner pipe of the concentric terminal MUST be the flue outlet.

3. Check that the Settings of the Combination Fan/Limit thermostat are correct (see below).Note: the limit thermostat is preset and sealed at the works and will need no adjustment.

To set the combination fan/limit thermostat first remove the cover by releasing the cover fixing screw andpulling off the cover. The three hands from left to right should be set approximately as follows subject to siteconditions (see Fig. 2.4).

HAND 1 FAN OFF SET TO 38°CHAND 2 FAN ON SET TO 57°CHAND 3 LIMIT SET TO 80°C

Always refit the cover and tighten the cover screw after adjustments.

4.4 Carry out a "Dry Run"

To ensure that all the controls are in safe working order, operate the fully automatic controls for the first timewithout the gas turned on.

To do this turn off the appliance gas isolating valve at the inlet to the heater.

Now using the installed external control turn on the burner.

The automatic sequence will now begin as described in Section 2. Following the purge period the electricignition will be heard and the spark may be observed via the viewing window on burner drawer at the side of theheater.

As the gas is turned off, the main gas flame will not ignite on the opening of the main gas valve and the controlwill go to the “lockout” condition. Press in the control box reset button, or the remote reset button if installed.

4.5 Fire the Burner

Turn on the appliance gas isolating valve and repeat the operations of 4.4 above.

Note at the first firing of the heater it may be necessary to repeat several times whilst purging the remainingair from the gas train.

The main burner will be ignited directly by the spark ignitor.The main gas valve will start the main burner at apreset step opening rate and then automatically proceed to the full rate within 45 seconds.


Fig. 4.2 S.l.T Nova 0-822-177

Burnerpressure testpoint

Inlet pressure testpoint

Gas Inlet

230v electricalconnection valve 1

Regulator (undercover)

Pilot gas outlet of valveblanked off

230v electricalconnection valve 2

Gas outlet toburner

Fig. 4.1 Controls Layout

FansConnections

Mains Filter forControls Only

Main Connection BoxBurner ControlBox

Air PressureSwitch

NaturalPositive Pipe

RedNegativePipe

RemoteResetLockoutDevice(Built intoControl onDMG)

SparkGenerator

CableTies

GasValve

SecondLimitThermostat

FanCapacitors


4.5.1 Commissioning the Gas Valves

All models of the heater are controlled by one S.I.T Nova 0-822-117 automatic gas valve.

Connect a manometer to the outlet (burner) pressure test point of the gas valve after first removing its screwcover (see Fig. 4.2).

The step opening feature of these valves is preset by the manufacturer and is not adjustable.

Set Burner Pressure (Natural Gas)The pressure regulator on the multifunctional gas valve is used which is situated under the screw on cover(see Fig 4.2). Adjust the burner pressure to the value as stated in the data table by turning the adjustingscrew slowly clockwise to increase pressure and vice versa.

Note: if any difficulty is found in obtaining the correct burner pressure then check that there is sufficient inletpressure to the valve, (20 mbar for G20) with the burner firing.

Under no circumstances should a regulator be set to a pressure over that where the pressure is no longerbeing changed.

Check Gas ConsumptionWherever possible a reading of the gas rate timed through the gas meter should be taken and compared withthe nominal rating in the Data Table in Section 2. The burner pressure should be adjusted to give this nominalgas rate.

Following burner pressure adjustment, allow the heater to operate for at least 15 minutes, turn the burner offand on, and then re-check settings. Remove manometer and refit all covers to the valve.

Set Burner Pressure (L.P.G.)For all L.P.G applications the pressure regulator in the S.I.T. Nova valve is put out of action, (see conversion toL.P.G, Section 10) hence there is no adjustment at this valve.The burner pressure is controlled by the appliance inlet pressure which must be 37 mbar for Propane (G31) or29 mbar for Butane (G30). The pressure test point for measuring the inlet gas pressure is situated at the top ofthe heater near to the connection point.

It is most important that the inlet pressure is closely controlled at these pressures under all load conditions.

4.6 Combustion Testing

Although there is no adjustment available to alter the combustion performance of the heater, other than burnerpressure, it is advisable to take combustion readings to determine the proper operation of the heater.

To do this the flue gas is sampled at the test point on the outlet of the flue and tested for contents of CO2

(carbon dioxide), CO (carbon monoxide) and temperature rise. The values of CO2 should be between 6.5% and

7.5% . CO should be no more than 0.0015% ( 15 PPM) and the temperature rise of the flue gases aboveambient should be 180°C to 210°C.

Combustion testing must be carried out with all covers etc. fully fitted and sealed as designed.

Ensure that all covers are fitted correctly and all test points are properly sealed before leaving the appliance torun normally.


4.7 External Controls

It is important to ensure that all controls fitted on site operate correctly and allow the heater to function inaccordance with these instructions.

Where fitted, operate the time switch, room thermostat and manual switch to ensure that they functioncorrectly. Set the time switch and room thermostat to the user's requirements.

4.8 Handing Over

When the commission is complete explain to the user the controls of the heater, including how to operate theheater and how to turn it off, using the controls fitted on site. Ensure that the user is shown and understandsthe emergency instructions in Section 9 of this Manual.


Fig. 5.1 Wiring of FRSA Axial Fan Unit Heaters

Section 5. Wiring Diagrams


Fig. 5.2 Wiring Diagram for FRSB and FRSC Centrifugal Fan UnitHeaters - Models 75 to 135


Fig. 5.3 Wiring Diagram for FRSB and FRSC Centrifugal Fan UnitHeaters - Models 150 to 210


Fig. 5.4 Wiring Diagram for FRSD Ducted Unit Heaters With NoBuilt In Fan


Fig 5.5 Individual Controls for All FRS Range Heaters

Fig 5.6 Methods of Connecting Remote Fan Motor for FRSD


Section 6. Servicing InstructionsAfter commissioning, the heater will require maintenance to be carried out at least once per year to ensurethat peak performance and safety are maintained. If the heater is used in a dirty or dusty area, then morefrequent maintenance may be necessary.

WARNINGOnly competent and Qualified Engineering Personnel should carry out servicing

and fault finding on this equipment.

Before any maintenance is carried out, ensure that both gas and electrical supplies are turned off as the fancan start automatically at any time.

NOTE 1: After any maintenance work always test fire the heater in the prescribed manner to make sure allsafety systems are in working order before leaving the heater to run normally.

NOTE 2: Check all pipe joints for gas soundness using an approved method. Any leaks found must berepaired before leaving the heater to fire normally.

NOTE 3: After routine maintenance, the commissioning procedure Section 4, should be carried out to ensurethat peak efficiency and safety is maintained.

Minor faults may be traced by use of the fault finding charts, Section 8.

6.1 Burner Maintenance

1. Remove the Burner Assembly as in 7.1.

2. Check condition of , the burners and clean any deposits from theburner paying particular attention tofluff etc., which may have formed in the injectors or venturi of the burner (see 7.4).

3. Check condition of ignition electrode and flame probe for erosion and damage to the ceramic insulation(see 7.3). Replace as necessary.

6.2 Fan/Motor Assembly - All Models

The main fan requires very little maintenance as the bearings are sealed for life and need no lubrication. If thefan blades need cleaning remove the fan guards and use a small brush or duster to clean the fan blades fromeach side of the fan(s).

The heat exchanger should remain clean unless some problem has developed with combustion. However, aninspection of the condition of the heat exchanger is well worth while especially looking for signs of overheatingat the lower edges which may indicate burner overfiring or reduced air flow over the heat exchanger. Anydeposits in the heat exchanger may be removed with a small flue brush and vacuum cleaner from the burnercompartment.

6.3 Heat Exchanger

A heat exchanger clean out panel is also provided at the top of the heater and is accessed by removal of theside panel of the heater oposite to the controls.The clean out panel doubles as the mounting plate for the flue fan assembly.

If it is necessary to use this access, remove all of the fixing screws securing the cover to the side of the fumebox. When replacing this cover it is most important that new gasket material is used to ensure the integrity ofthe combustion zone which must be maintained as room sealed. It is also important to ensure that the flueoutlet of the fan unit is again sealed onto the outlet flue.


6.4 Gas Control Valves

There is no regular maintenance required on these devices. To change gas control valves, see Section 7.2.

6.5 Flue Fan

The flue fan should be inspected to ensure that the fan impeller is in good condition and that no debris hasentered the flue system.

If the fan is found to be damaged, then a replacement unit must be fitted of the correct type (see Data Tables).


Section 7. Removal & Replacement of PartsSee warnings and notes at the start of Section 6 before removing or replacing parts.

7.1 Burner Tray

The burner tray may be removed from the heater only from the right hand side of the heater when viewed fromthe front. It is best removed along with the gas valve as an assembly. Clear access at this side of the heater isrequired for at least the full width of the heater to allow burner withdrawal.

7.1.1 To Remove the Burner Tray

Open the heater right hand side panel to expose all of the controls. The burner drawer is held in place by theseries of set screws.

Disconnect the gas supply pipe at the gas valve inlet flange being careful to retain the four fixing screws and"O" ring seal.

7.1.2 Remove Electrical Leads

Unplug the two elctrical connectors from the gas valve.

Unplug the flame probe lead from the Flame probe and the HT lead from the spark igniter.

7.1.3

Unscrew the set screws securing the burner tray (Fig.7. 1 ), and pull out the tray from the side of the heater.

7.1.4 Replace Burner

To replace the tray reverse the above steps ensuring that the tray is firmly in its correct place with the fixingscrews tight ,and that the gas pipe work is sound.

IT IS MOST IMPORTANT TO ENSURE THAT THE BURNER DRAWER IS PROPERLY FITTED TO PROVIDEAN AIR TIGHT SEAL. THIS WILL REQUIRE THE REFITTING OF ALL OF THE FIXING SCREWS AND MAYREQUIRE THE REPLACEMENT OF THE SEALING GASKET.

7.2 Gas Control Valves

Open the heater side panel as in 7.1.

7.2.1

Isolate and remove the gas supply at the inlet flange of the gas valve being careful to retain the four screwsand "O" ring seal..Unplug the two elctrical connectors from the gas valve.

7.2.2

Using a short screwdriver , unscrew the outlet flange of the gas valve being careful to retain the four screwsand "O" ring seal..The valve is now free to be removed.


7.2.3 Refit Gas Control

Refitting is a direct reversal of the above ensuring that the "O" ring seals are correctly fitted and gas tight andthat the valve is installed with the gas flow in the correct directionAfter changing a gas valve it is essential that the commissioning procedure (Section 4) is carried out in full.

7.3 Flame Probe or Ignition Electrode

The flame probe and ignition electrode are made to be different from each other so that they may not beinterchanged.To gain access to either requires the same operations.

7.3.1

Remove the burner tray as in 7.1 (it will be possible to pull open the burner drawer by about 150mm to gainaccess to the electrodes).

7.3.1.1 Ignition Electrode

The Ignition electrode is the one situated at the centre of the burner near to the cross lighting brackets. Thiselectrode is designed to give a spark gap of 4 to 6mm between the electrode tip and the centre flame ports ofthe burner.

7.3.1.2

To remove, pull off the H.T. "Rajah" connector from the ignition electrode.

Using suitable spanners unscrew the securing nut that holds the electrode to the side of the burner drawer.

To replace directly reverse the above ensuring the proper spark gap and that the fixing of the electrode is airtight to the burner drawer..

7.3.1.3

The flame probe is situated towards the front of the heater and is designed to have the end of the electroderunning parallel to the burner at a position to impinge with the edge of the flame.

To remove, pull off the tag connector from the flame probe.

Using suitable spanners unscrew the securing nut that holds the electrode to the side of the burner drawer.

To replace ,directly reverse the above ensuring the position of the flame probe and that the fixing of theelectrode is air tight to the burner drawer.


First Burner withno Crosslighter

Burner withCrosslighter

Crosslighter

Injectors

Flame Probe Ignition Electrode Spark gap 4 to 6mm to CentreBurner Ports

Rear Baffle

Manifold

ViewingWindow

FlameProbe

Plug for SecondValve

IgnitionElectrode

Burner DrawerFixing Screws

Burner DrawerFixing Screws

Plug for First Valve

OutletFlange

Inlet Flange

Fig 7.1 Burner Tray Details


7.4 Main Burner Bars/Injectors

Remove the burner tray as in 7.1.

7.4.1

To remove the burner bars first remove the screw securing the burner rear baffle and pull it upwards.

7.4.2 Remove Burner Bars

The individual bars may now be removed by pulling up the front end of each one clear of the mounting tray andthen pulling the burner forward off its injector.

Note: the burners are all the same except the first burner on left from the front (see Fig 7.1). This burner hasno cross lighting bracket and has two mounting tongues to prevent incorrect fitting.It will be found easier to remove burners starting from the opposite end of the burner tray.

7.4.3 Remove Injectors

If the injectors are being removed they are now accessible, each one is screwed into its port of the manifoldwith a soft metal sealing washer and may be removed using a 13mm spanner.

7.4.4 Re-fit Injectors

On replacing injectors ensure that the correct ones for the gas in use are used as stamped on the injector(see Data Tables). They must seat onto the soft metal washer to effect a good seal onto the manifoldshoulder. It is recommended that new soft washers are used at each refitting of the injectors.

7.4.5 Re-fit Burner Bars

When refitting the burner bars start by fitting the No.1 burner (without cross lighting bracket) and ensure thatthe burner is pushed fully home against the injector and then pushed down to the bottom of its mounting slots.Repeat for each burner in turn until all the burners are back in place.Replace the rear burner baffle ensuring that it engages into the slot in the bottom of each burner tube inletbracket.Replace the fixing screw for the rear baffle.

Continue to reassemble reversing the above instructions.

Note: It is most important to ensure that the burner drawer is properly fitted to provide an airtight seal. Thiswill require the refitting of all the fixing screws and may require the replacement of the sealing gasket.

7.5 FRSA Axial Fan Guard/Motor Assembly

The fan guard & motor for the FRSA range is supplied as a complete assembly and therefore does not need tobe disassembled.

The assembly is secured to the heater using the four fixing screws securing the guard to the heater withrubber washers to reduce noise and vibration..

7.5.1 To Remove the Fan Assembly

Disconnect the electrical cables from the fan terminal block at the rear of the heater, carefully noting thecolour code of the wires to the fan.

Remove the four screws securing the fan guard to the heater carefully retaining the rubber washers.


7.5.2 To Replace the Fan Assembly

To replace the fan assembly reverse the above procedure ensuring that the rubber washers are fitted to theguard mountings to reduce vibration.

It is also most important that the colour code of the fan wires is strictly observed to ensure correct operationand being careful to use the correct neutral connection. The Blue Neutral is for the main fan the Blue/Whiteneutral is for the flue fan and must not carry the load of the main fan

This is because the burner electrical supply is protected from mains borne interference by the use of a specialconditioning filter which is not capable of carrying the full load of the main fan.

It is sound practice to replace the fan capacitor when changing a fan.

Check that the fan blades are free to rotate without catching before turning on the power to the fan.

7.6 FRSB and FRSC Fan/Guard/Motor Assembly

The direct drive fan for the FRSB range is supplied as a complete assembly and therefore does not need to bedisassembled.

7.6.1 To Remove the fan/s.

Disconnect the electrical connections from the terminal block at the rear of the heater making a careful note ofthe positions of the connecting wires and identifying the current speed setting.

Remove the fan / motor assembly by removing the fixing screws whilst supporting the weight of the fan(approx. 19 kg) and making a careful note of the fan orientation.

For the FRSC version fitted with an inlet spigot assembly the fan/s may be accessed through the removablecovers on the sides, top and bottom of the spigot, as required.

7.6.2 To refit the fan/s

To reassemble reverse the above ensuring that the correct motor connections are used as identified whendisconnecting and that new rubber seal is used between the fan flange and the heater rear panel. It isimportant that the fan is fitted to the rear panel in its correct orientation with the curved surface upwards.

It is most important that the colour code of the fan wires is strictly observed to ensure correct operation, andbeing careful to use the correct neutral connection. The Blue Neutral at the heater is for the main fan the Blue/White neutral at the heater is for the burner controls and must not carry the load of the main fan .This isbecause the burner electrical supply is protected from mains borne interference by the use of a specialconditioning filter which is not capable of carrying the full load of the main fan..

Check that the fan blades are free to rotate without catching before turning on the power to the fan.

The three speed winding connections are:

Low speed: White N, Red Live. The other two windings are "parked" separately in spare terminals

Medium speed: White N, Blue live. The other two windings are "parked"separately in spare terminals

High speed: White N, Black live. The other two windings are "parked" separately in spare terminals


7.7 Combination Fan/Limit Thermostat

To gain access to this thermostat, open the heater side panel. Remove the thermostat cover retaining screwand pull of the cover.

7.7.1

Disconnect the electrical connections by pushing in with a small screwdriver and pulling out the wires (seeFig. 2.1).

7.7.2

The earth wire is held under a screw connection.

7.7.3

Unscrew two fixing screws and withdraw the unit from the cabinet feeding the cables through the grommetedhole in the thermostat base.

7.7.4

To refit, reverse the above procedure reusing the grommet and reset as in the commissioning instructions,Section 4.

Note: the new thermostat should have the limit setting sealed by a suitable method to prevent unauthorisedadjustment.

WARNINGWhen replacing a combination thermostat ensure that the link is removed (see Fig. 2.1).

Permanent damage will be caused by leaving this link in.


7.8 Second Limit Thermostat

Remove the fan assembly from the heater rear (see 7.6).

7.8.1

Release the sensing phial from its clamp on the bottom of the heat exchanger and carefully pull the capillarysensing probe through its access hole in the side of the heater.

7.8.2

To refit a thermostat, first carefully straighten the capillary tube - it is important not to kink or crack it.

Proceed to replace by reversing the above procedure ensuring that the sensing bulb at the end of the capillarytube is positioned against the base of the heat exchanger towards the centre of the fan outlet (where there aretwo fans the position of the sensing bulb should be towards the centre of the fan on the opposite side of theheater from the controls).

Any spare capillary tube should be left carefully coiled in a position that will allow the burner drawer to beremoved without snagging on it.

7.9 Air pressure switch (Removal)

To replace the air pressure switch pull off the two coloured air pressure tubes noting there position .Disconnect the two push on electrical connections noting there position.Remove the two corner fixings of the pressure switch.

7.9.1 Replacement

To replace reverse the above ensuring that one of the correct calibration is used as specified in the data tablefor the model. Only pressure switches that have been calibrated by Roberts-Gordon for use on the specificmodel of heater may be used.

There is no adjustment necessary as the pressure switch is factory preset.

7.9.2 To test operation

To test for correct operation of the pressure switch requires that an accurate micromanometer is connected toread the same differential pressure as the pressure switch.This will require two temporary tee pieces inserting into the pressure tubes so that the manometer may beused.

With the burner running read the pressure indicated on the micromanometer, it should be well above the setpoint as indicated in the data tables for the model.

Apply a suitable clamp to the RED coloured Negative sample tube on the heater side of the temporary tee andslowly close off the pressure to the pressure switch and micro manometer.The pressure switch should turn off the burner at a pressure indicated on the micromanometer within ± 0.3mbar of the set pressure as indicated in the data tables.If the pressure switch is outside of this tolerance it must be changed.


Section 8. Fault Finding

WARNINGFault finding must only be carried out by experienced engineers who fully understand

the operation of the burners. There is a risk, including that of explosion, when burners are faultyand not repaired correctly.

STARTAssuming gas andelectrical supplies

are ON.

Is theGreen Light ON?

Check externalcontrols are ON and

supply is sound.

Check for operation ofLimit Thermostats

Is Red 'Lockout'warning light ON?

Test Burneras in 8.1.

Does the Fan run?

Press in Whitebutton on

combinationthermostat.

Fan runs now?

Use 8.4 to test fan.

See Section 4.3 tocheck Fan Stat

Settings.

ReplaceCombinationThermostat.

Does burner stopafter running forseveral minutes

(with controls stillon)?

Has the burner'Locked Out'?

Check for correctoperation of fan.

Check operationand setting of

Combination Stat.Repair or replace as

necessary.Use 8.1 to test burner.

Following the replacement or adjustment of parts, carry out the commissioning procedure as specified inSection 4.

Heater Operating

YES

NO

NO NO

YES NO NO

→→→→→→→→→→

↓↓↓↓↓ ↓↓↓↓↓YES

↓↓↓↓↓

NO

←←←←←

→→→→→

→→→→→ →→→→→ →→→→→

→→→→→

↓↓↓↓↓

↓↓↓↓↓

↓↓↓↓↓YES

↓↓↓↓↓YES

←←←←←

→→→→→ →→→→→ →→→→→

↓↓↓↓↓YES

↓↓↓↓↓NO

↓↓↓↓↓YES

↓↓↓↓↓YES

↓↓↓↓↓

←←←←←


8.1 Gas Burner Fault Finding

Start assuming that there is proven fuel and electricity supply with all external controls on (Greeen light on).

STARTAssuming gas and

electrical supplies are ON.Green light ON.

Is the air pressure switch atrest (contacts open)?

See Section 4.1.2 & 7.9for testing

Test switch. Replace.

Does the flue fan run?

Does 'Lockout' occur beforethe burner fan has run for

10 seconds?

Use 8.2 to check flamemonitoring

Does 'Lockout' occur afterthe burner has run for 10seconds, but before the

burner fires?

Check setting of airpressure switch (see 4.1.2).

Check that the flue fan isoperating. Check gas valve

plugs are fitted.Check that the flue system

and flue fan are clean.

Check ignition circuit, fuelsupply and automatic gas

valve.

Does the burner fire?

Does 'Lockout' occur? Use 8.2 to check flamemonitoring.

Heater Working

NO NO

YES

NO NO

NO

YES

←←←←←

YES

↓↓↓↓↓

↓↓↓↓↓

YES

↓↓↓↓↓

→→→→→ →→→→→

↓↓↓↓↓

→→→→→↓↓↓↓↓

↓↓↓↓↓NO

→→→→→ →→→→→↓↓↓↓↓

↓↓↓↓↓↓↓↓↓↓YES

←←←←←

→→→→→

↓↓↓↓↓YES

←←←←←

→→→→→NO

↓↓↓↓↓←←←←←


8.2 Flame Supervision Systems

Gas fired heaters use a rectification flame probe to monitor the flame.

To connect a suitable meter into the circuit to measure the flame signal current.Disconnect the lead from the flame probe, (push on tag connector).Connect a suitable DC ammeter between the flame probe and the wire just disconnected.Should the meter read backwards, then reverse its connection.

Maximum flame currentwith no flame:

0 to 0.5 m A D.C.

Minimum flam current1.0 m A D.C.

Typical flame current3.0 to 5.0 m A with main

burner ON

Connect a D.C. ammeter in serieswith the flame probe using the jack

plug provided.

Turn on all controls and ensure thatthere is a supply

to the burner.Green light ON.

Is there a current flowing inthe flame probe circuit with

no flame present?

Inspect and test the flameprobe and wiring for

damaged insulation andshort circuits to earth.

Repair or replaceas necessary.

Does 'Lockout' occur whenthere is a flame present?

Check adequate gaspressure.

Replace flame probe andensure that it is fitted

correctly.

Check for correct earthingof heater.

Check that live and neutralpolarity are correct.

Control box faulty.Replace with correct type.

Burner Operating

YES

YES

←←←←←

↓↓↓↓↓

↓↓↓↓↓

→→→→→ →→→→→

↓↓↓↓↓↓↓↓↓↓NO

→→→→→ →→→→→

↓↓↓↓↓NO ↓↓↓↓↓

↓↓↓↓↓←←←←←

The Satronic DMG control is able to provideFlame Current and Lockout information via aspecial reader from the built in Lockout ResetButton (see 8.2.1).


8.2.1.2 Lockout Diagnosis

In case of a failure the LED is permanently illuminated. Every 10 seconds the illumination is interrupted by aflash code, which indicates the cause of the error. Therefore the following sequence is performed which isrepeated as long as the unit is not reset.

8.2.1 Satronic DMG Control Information System

The information system is microprocessor based and reports on all aspects of burner control box operationand flame supervision. It informs continuously about the actual programming sequence the unit is justperforming. Besides monitoring of the programming sequence it also allows to identify errors during start up ofoperation without any additional testing devices. The automatically performed diagnosis is a valuable toolwhich facilitates service/maintenance work and therfore saves costs. the analyses of the error cause can bedone directly on stage or if not possible afterwrds as the lockout reason is stored in a non volatile lockoutmode memory.

The information system communicates with the outside world using a LED (the used Flash Code is similar tothe Morse Code). The messages are optically transmitted by an appopriately flashing LED. Using anadditional terminal (optional), the messages can be recorded and displayed in easy readable form.

8.2.1.1 Programming Sequence Display

The built in microprocessor controls not only the programming sequence but the information system too. Theindividual phases of teh programming sequence are displayed as Flash Code.

The following messages can be distinguished:

MESSAGE FLASH CODE

Waiting for air proving switch l l .

Pre purge tv1 l l l .

Pre-ignition tvz l l l l .

Safety time ts l .

Delay 2nd stage tv2 l l .

Running l _

Low mains voltage l _

Description:l = short pulse = long pulse

. = short pause_ = long pause

Error DiagnosisError Message Flash Code Possible Fault

Lockout safety time l within lockout safety time no flame establishment

Stray light l l stray light during monitored phase, detector may be faulty

Air proving switch in closedposition l l l air proving switch contact welded

Air proving switch opened l l l l air proving switch opens uring start or operation

Loss of flame l loss of flame during operation

Flash Code for Manual Lockoutmanual/external lockout l l _


8.3 Solenoid Valve CircuitTo test the operation of a solenoid valve requires both electrical and mechanical checking.To test the mechanicl operation of a valve requires a suitable manometer to be fitted to the outlet of the valveand the rise in pressure observed at the appropriate time.

START

Test for 230v across valve supplyterminals at the appropriate time.

Fault elsewhere.Check all connections and controls

including limit thermostats.

Pressure should rise on outlet whenvalve energises.

Test gas pressure at inlet of valve. Fault elsewhere.

Solenoid valve faulty.Replace as necessary.

Test gas pressure at outlet of valve.

Valve working

NO

NO

NO

↓↓↓↓↓

↓↓↓↓↓YES

→→→→→

←←←←←

→→→→→

→→→→→YES ↓↓↓↓↓

←←←←←

8.4 Main Fan Circuit

Fault elsewhereCheck for electrical supply230v L to N

Fan does not runautomatically.

Test for 230v betweenterminals 1 and N in

terminal block.

Press manual switch ofcombination thermostat.

Fan runs now?

Fault elsewhere

Fan motor or capacitor faulty.Replace as necessary.

Check settings ofcombination thermostat.

Fan now operates

NO NO

NO NO

YES

↓↓↓↓↓

→→→→→ →→→→→

→→→→→ →→→→→

↓↓↓↓↓YES

↓↓↓↓↓YES

←←←←←

↓↓↓↓↓


Section 9. User InstructionsThe normal user controls are installed remote from the heater and as a minimum will consist of a roomthermostat. Where a Roberts-Gordon remote control unit is used the operation of the heater will be fullyautomatic from this control as described in the instructions supplied with the control.

The only user controls situated at the heater are:

The burner lockout reset button see 9.2.1The fan run button see 9.2.2The limit thermostat reset see 9.2.2The second limit thermostat reset button see 9.2.3

9.1 Heater Operation

When the heater has been switched on (see Section 9.3) and the remote thermostat and/or time switch callsfor heat, the automatic control box turns on the burner and constantly monitors its safe operation. (seeSection 2.2).

When the heat exchanger is sufficiently heated, the fan thermostat turns on the main fan(s) and warm air isdischarged from the front of the heater.

Note on some fully ducted heaters the fan will come on during the burner firing cycle and not wait for thetemperature rise.This is to ensure that there is always a proper operation of the heater under all possible duct conditions.

When the environmental working temperature, as set on the remote thermostat is achieved, the burner shutsoff. The main fan runs until all the heat has been extracted from the heat exchanger and the fan thermostatdetects a drop in leaving air temperature sufficient to turn it off. The heater then is at rest until the beginningof the next cycle.

WARNING:The main electrical isolator should only be used in an emergency and should not be used for

closing down the burner, as this switches off the main fan prematurely and may damage the heatexchanger. Such action may cause a fire hazard and invalidate the warranty .

9.2 User Controls

The following controls are available for the user, at the heater.

9.2.1 Burner Lockout Reset Button

This button which is built into the burner control box, and will illuminate the red warning light at the front of theheater when the control has gone to safety shut down ‘lockout’. This may be caused by flame failure.

After lockout has occurred, a waiting time of one minute must be observed before an attempt to reset thecontrol is made by pressing in the reset button on the side of the heater.

WARNING: If the control should go to ‘lockout’ again, do not make more than three attempts at restarting the

heater. The fault must be traced and repaired by a competent person.


9.2.2 Combination Fan/Limit Thermostat

This is located on the top right hand side of the heater inside the opening side door, see Fig. 1.1.This control ensures the heater does not blow cold air in the normal heating cycle and protects the heatexchanger against overheating.

Fan Thermostat

Although it should not be necessary for the user to touch this control, it is worth noting that:

Pressing in the White button on the combination fan limit thermostat causes the main fan(s) to runcontinuously.

For normal operation this button should be pulled to the out position.

Limit Thermostat

If for any reason the main fan should fail or the air flow is reduced the built in limit thermostat will cause theburner to go to safety shut down ‘lockout’. This condition will persist until the fault is corrected and the manualreset button is operated. The combination fan/limit thermostat is preset during commissioning (see 10.2.7).

9.2.3 Secondary Limit Thermostat

There is also a secondary limit thermostat situated on the heater rear panel near to the electrical cable entrypoints. This is a hand reset device designed to fail safe and give further protection against fan failure.

To reset this thermostat unscrew the plastic cover and press in the central reset button.Note: the heat exchanger must have cooled for reset to be possible.

9.3 Operating Instructions

9.3.1 Turning on the Heater

Ensure that the electricity and gas supplies to the heater are on and (where fitted) reset the time switch asdescribed in the makers instructions.Check that the external controls are ON i.e. check that the time switch is in an “ON” period and that thethermostat is set to the required temperature, (which must be above the ambient temperature for the heater tooperate).

The green light will now be on, and the heater will operate fully automatically under the control of the burnercontrol box along with the time switch and thermostats, as fitted on site.

Following long shut down periods the control may go to “lockout” (indicated by the red “lockout light” beingilluminated). To reset press in the “lockout reset button” and the sequence will begin again automatically.

“Lockout” should not occur during normal operation of the heater and indicates that there is a fault conditionwhich must be corrected.




9.3.2 To Turn the Heater OFF (Short Periods)

Operate the external controls (Time switch or room thermostat) to an off position. The burner will turn offimmediately, but the distribution fan will continue to run for a few minutes to dissipate the heat from the heatexchanger.

To restart turn the control used above to “ON”.

9.3.3 To Turn the Heater OFF (Long Periods)

Carry out the operations of 9.3.2. Allow the fan to stop running automatically. Turn off the gas and electricalsupplies.

To start the heater again, turn on the gas and electrical supplies and carry out the operations in 9.3.1.

WARNINGThe electrical isolator must not be used for turning the heater off other than in an emergency. This

will prematurely turn off the distribution fan and will seriously shorten the life of the heatexchanger, invalidating the warranty. Such action may also cause a fire hazard.

9.4 Simple Fault Finding

Some possible reasons for the heater not operating are:-

1. Gas supply not turned ON.

2. Electricity supply not turned ON.

3. The installed time and/or temperature controls are not ON.

4. Green light will not come on, check 2 & 3 above orOne or both of the limit thermostats may have operated. This may be caused by inadvertentremoval of the electrical supply or failure of the distribution fan.

Limit thermostat 1 is on the combination thermostat. To reset, press in and release the redresetbutton (see 9.2.2).

Limit thermostat 2 is under the screw on cover on the rear of the heater near the Electricalcable entry glands (see 9.2.3).

To reset remove the screw on cover and press in the reset button. Replace the cover after use.

If the Limit thermostats persistently operate then there is a fault which must be investigatedby a competent engineer.

5. If under fault conditions the burner fails to ignite for any reason then it will go to thelockout condition this will be indicated by the red lockout warning light on the front of the heater.

To reset press in and release the lockout reset button (see Fig. 1.1).

Any other problem will require the assistance of a Service Engineer.




9.5 Service Requirements

This heater will require servicing at least once per year except when operating in a dirty of dusty area, whenmore frequent service may be necessary. The service should be carried out by a competent engineer inaccordance with the requirements of this manual.

For service contact your Heating Supplier.

The heater cabinet may be cleaned using a damp cloth with a little domestic detergent.Do not use excessive water or abrasive materials.

EMERGENCY INSTRUCTIONS

If a gas leak is suspected, turn off the gas supply and extinguish all naked flames. DO NOT operate any electrical switches or machinery.

Evacuate and ventilate the area and contact your local gas supply undertaking immediately.

DO NOT SEARCH FOR GAS LEAKS WITH ANY NAKED FLAME


Section 10. Conversion Between Gasses10.1 General

All versions of the heaters use the same main burner bars.

Natural GasAll natural gas versions use the same main burner injectors, marked 594.The gas valve contains a gas pressure regulator to allow for setting of the burner pressure.

L.P.G.All L.P.G. versions use the same main burner injector, marked 54.The gas valve DOES NOT contain a gas pressure regulator.The correct operation of the heater depends on the close control of the gas inlet pressure to the appliance.

10.2 Burner Conversion

To convert the burner assembly from one gas to the other is the same for all models of heater.Remove the burner tray as in Section 7 of these instructions and remove all of the main burner injectors.Replace with the ones for the new gas following the instructions in Section 7.

10.3 Gas Valves

All of the MKII FRS range heaters are fitted with S.I.T. Nova main valves which may be converted to operatewith or without a burner gas pressure regulator.

To Convert NOVA Valve from Natural Gas to L.P.G.

Remove the cover of the pressure regulator.Completely unscrew the regulator adjusting screw and remove it complete with its spring.Replace the adjusting screw and original cover with the blanking nut attachment.This device screws fully into the body of the regulator until it stops and puts the regulator out of action.The step opening feature of the main valve will still operate.Then carry out the commissioning procedure as detailed in Section 4.

To Convert NOVA Valve from L.P.G. to Natural Gas

Reverse the instructions above Refitting the regulator spring, adjuster and cover.Then carry out the commissioning procedure as detailed in Section 4.

Fig 10.1 Conversion of S.I.TNova gas valve betweengasses


Section 11. Parts List

DESCRIPTION PART NUMBER

Axial Fan S4E 350 A 262Axial Fan S4E 400 A 263Axial Fan S4E 420 A 264Torin 270-270 three speed centrifugal fan A 047Torin 241-241 three speed centrifugal fan A 049Torin AUO 76416 flue fan - models 75 - 135 A 993Torin AUO 75125 flue fan - models 150 - 210 A 991

Automatic ignition gas valve .S.I.T. Nova (All gasses) L 421Exclusion screw for Nova valves (All Types) for L.P.G. L 425

Main burner injectors, natural gas B 109Main burner injectors, L.P.G. gas B 101Sealing washers for main burner injectors B 210

Honeywell combination fan/limit thermostat. K 017Second limit thermostat K 120

Note: Always quote the model and serial number of the heater when ordering spare parts.

Parts available from:

Roberts-GordonOxford Street, Bilston, West MidlandsWV14 7EG

SWITCHBOARDTel: 01902 494425Fax: 01902 403200

SERVICEService DepartmentTel: 01902 498733Fax: 01902 401464

SPARESTrade CounterTel: 01902 499051Fax: 01902 492411


Section 12. Commissioning Data Sheet

GAS RATE MEASURED AT METER M3/hr (ft3/hr)

AMBIANT TEMPERATURE °C

GROSS STACK TEMPERATURE °C

NET STACK TEMPERATURE °C

CARBON DIOXIDE IN FLUE CO2 %

CARBON MONOXIDE IN FLUE CO. P.P.M.

ESTIMATED EFFICIENCY % (State net or gross)

COMMENTS

HEATER LOCATION

MODEL SERIAL NUMBER

GAS TYPE:NATURAL/P.G.

CUSTOMER

SITE ADDRESS

INLET GAS PRESSURE mbar BURNER GAS PRESSURE mbar

ENGINEER SIGNATURE DATE

C O N T A C T S

SERVICE Tel: 01902 498733Fax: 01902 401464

SPARESTel: 01902 499051Fax: 01902 492411

MAIN SWITCHBOARDTel: 01902 494425Fax: 01902 403200

Roberts-GordonOxford Street, Bilston, West Midlands WV14 7EG

Tel: 01902 494425 Fax: 01902 403200e-mail: [email protected]

www.combat.co.ukwww.rg-inc.com

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