february 2008 mv metal-clad...

© ABB Group January 4, 2015 | Slide 1

MV Metal-Clad SwitchgearThe safest, most reliable Switchgear in the market today

February 2008


Arc-Resistant Standards

� Introduction – Today’s Topics

� What is Arc Flash and the risks it represents

� Arc-Resistant Switchgear Standards

� ABB Switchgear Offering

� Characteristics of SafeGear Arc-Resistant Switchgear

� Other Safety Features available in Switchgear today


What is an Arc Flash?

� The result of a rapid release

of energy due to an arcing fault

between phases, neutral or a

ground.

�An arc arises when at least part of the current passes through a

dielectric, usually air

� Maximum peak power up to 40 MW

�Arc temperature up to five times the surface temperature of the sun

(20,000°C)

� Light intensity more than 2000 times

that of normal office light

� Volumetric expansion approximately

40,000+ - 1

Temperature of

the sun surface is

about 5000°C.


Arcing Incidents Do Happen

Fault characteristics

An arc arises when at least part of the current

passes through a dielectric, usually air

Maximum peak power up to 40 MW

Arc temperature up to five times the surface

temperature of the sun (20 000°C)

Light intensity more than 2000 times that of

normal office light


Arc Flash Danger Statistics

� Currently, OSHA lumps Arc Flash incidents in with electrical incidents.

� A recent survey showed that 5-10 people per day go to burn centers due to arc flash incidents – that does not include those going to local and regional hospitals

� That is 2000-3500 people a year in the US!

� With the high mortality rate of burn injuries, this can translate to hundreds of deaths a year

� IEEE did a study with a large utility and over the last 53 years, they have had 1 arc flash incident every 18 months.


Arcing Incidents Do Happen

Security Video of Arc flash incidentDistributed by NFPA


Arc-Resistant Switchgear

� Causes of internal arc faults

� Improper maintenance, mechanical, and interlock

failures

� Failure to follow procedures

� Gradual component or insulation breakdown

� Foreign objects, rodents, snakes, etc.

� Effects of an internal arc fault

� Pressure increase in an enclosed compartment

� Function of arc voltage, current, number, and duration of arcs, volume

� Rapid onset (10-15 ms) results in explosive forces

� Thermal effects, hot gases

� Catastrophic to nearby personnel and equipment


Evolution of Arc-Resistant Standards

� Interest in Europe – uninsulated bus was common

� Annex AA to IEC 298 was approved in 1981

� EEMAC G14-1 was published in 1987 in Canada

� Type A – arc-resistant construction at the front only

� Type B – arc-resistant construction at the front, back, and sides

� Type C – arc-resistant construction at the front, back, and sides, and between compartments

� IEEE C37.20.7-2007 includes

� Type 1 – similar to EEMAC Type A above

� Type 2 – similar to EEMAC Type B above

� Annex A addresses suffixes “B” and “C”

� Type 1C – Type 1, but also with arc-resistance designs or features between adjacent compartments

� Type 2B – Type 2 with LV instrument compartment door open – relay and maintenance personnel survive

� Type 2C – Type 2 with arc-resistance features between adjacent compartments –switchgear survives with minimum damage

� Type 2BC – The ultimate in protection – combines types 2B and 2C


Industry Recognized Arc-Resistant Standards

� OSHA 29 Code of Federal Regulations (CFR) Part 1910, Subpart S

� NFPA 70E-2004, “Standard for Electrical Safety in the Workplace”

� IEEE 1584-2002, “Guide for Arc Flash Hazard Analysis”

� IEEE C37.20.7-2007, IEEE Guide for Testing Medium-Voltage Metal-Enclosed

Switchgear for Internal Arcing Faults


Arc-Resistant Standards

� Current Requirements and How They Apply

� OSHA 29 Code of Federal Regulations (CFR) Part 1910, Subpart S

� Safe practices to prevent electrical shock or burns must be

implemented

� Mandates that exposed workers must be qualified

� Requires provisions for the appropriate personnel protective

equipment (PPE)

� NFPA 70E-2004, “Standard for Electrical Safety in the Workplace”

� Details steps to comply with the OSHA requirements

� Worker training

� Appropriate, safe tools

� Safety program

� Arc flash hazard calculations

� PPE

� Equipment warning labels


THE NEW NFPA 70E – 2009, TABLE 130.7 (C) (9) Arc-Resistant SWITCHGEAR TYPE 1 OR 2

Hazard/Risk Category for Arc-Resistant Switchgear

Applies to clearing times of <0.5 sec with a perspective fault current not to exceed the arc-

resistant rating of the equipment.

Insertion or removal of CBs from cubicles, doors open 4

CB operation with enclosure door closed 0

Insertion of removal of CBs from cubicles, doors closed 0

Insertion or removal of ground and test device with door closed 0

Insertion or removal (racking) of voltage transformers on or off the bus, door closed

0

Work on control circuits with energized electrical conductors and circuit parts 120V, exposed

2


Arc Flash Introduction - Mitigation Techniques

� Redirecting energy away from workers

� Reducing the arcing current (En ~Ia)

� Not effective method as test data is required for current limiting devices (fuses)

� Increasing the working distance (E~1/D)

� Using remore racking device, remote operating devices incident energy might be reduced

� Reducing the clearing time (E~t)

� Zone selective interlocking

� slow (100ms) + breaker operate time)

� can not be used for retrofit installations

� Bus bar protection

� expensive to install due to number of CT’s

� Light Detection


ANSI C37.20.7 Accessibility Types

� 1

� Front only

� 1C

� Front plus between compartments within a section or between adjacent

vertical sections (except main bus compartment)

� 2

� Front, back, and sides

� 2B

� Isolation of the Low Voltage Compartment with the instrument door open

� 2C

� Front, back, and sides, plus between compartments within a section or

between adjacent vertical sections (except main bus compartment)

� 2BC

� Offers compartment to compartment and low voltage isolation. Offers the

very best solution for personnel protection and system reliability.

SafeGear meets IEEE C37.20.7-2007

Type 2, 2B, 2C and 2BC!


Arc Faults

SafeGearConventional Switchgear


Pressure Buildup

0

100

200

300

400

500

600

700

800

900

1 3 5 7 9

11

13

15

17

19

21

23

25 time (ms)

PS

I

enclosure

rupture

Pressure measurements

vent flap

opens

Successful SafeGear test

SafeGear

conventional


Introduction to ABB ANSI Switchgear

� 5 to 15 kV metal clad switchgear

� Advance

� Traditional non-arc-resistant switchgear

� SafeGear

� Meets ANSI Standard C37.20.7-2007 for arc-resistance

� Four versions – Types 2, 2B, 2C and 2BC available

� Vacuum circuit breakers

� AMVAC

� Magnetically actuated mechanism

� ADVAC

� Spring operated mechanism


Ratings

Nominal Voltage 4.16 7.2 13.8

BIL (kV) 60 95 95

Continuous Current (A) 1200 1200 1200

Main Bus 2000 2000 2000

3000 3000 3000

Forced Air Cooled* 4000 4000 4000

Short Circuit (kA) 20 20 20

K Factor = 1.0 25 25 25

31.5 31.5 31.5

40 40 40

50 50 50

Ratings

4000 A rating availab le for Advance only.


ABB Metal-Clad Switchgear

� Features

� Galvanic construction

� Hem bending

� Modular design

� Bolted frame

� Instrument compartment

� Breaker compartment

� Bus and cable compartment

� Potential transformer compartment

� Arc-resistant switchgear

� SafeGear

� Power distribution center

� Plenum

� Circuit breaker technology

� ADVAC

� AMVAC magnetically actuated circuit breaker option


Galvanic Construction

�Resistant to rust,

corrosion and

scratches

�No paint required

�Highly reflective

(Side view with covers removed)


Hem Bending

� No sharp edges for

increased safety

� Improved rigidity

� Reduces arc propagation

� Forms a self-supporting

structure

Hem bending creates a rigid structure and sturdyconstruction in metal-clad switchgear (reinforced,

arc-resistant door construction shown).


Modular Design

� Bolted construction enables faster replacement and modification in the field

� Allows for easy replacements, repairs, and specialized configurations

� Maintains the smallest, compact product


Instrument Compartment

� Total isolation from medium voltage components

� No instruments on breaker door

� Galvanic interiors provide superior reflectivity inside compartments

� Available in four sizes

� 19”, 38”, 57”, 95”

� Gasketed door

� Easy accessibility for operators

� Truck operated cell switches located in the low voltage compartment for easy access and to minimize exposure


Breaker Compartment

� Dual safety shutter actuators

� Interlock prevents manual

operation

� Mechanically forced by breaker

movement

� Shutters grounded by cable

� Clear Lexan shutters available

� Position indicator

� Connected

� Test

� Disconnected


Breaker Compartment

� Automatic secondary

disconnect

� Provides improved safety for

workers while operating the

breakers when using SafeGear

� Single or double plug

secondary contacts

� Grounding contact

� Interference block

� Prevents installing undersized breakers


Bus & Cable Compartments

� Copper bus

� Epoxy coated bus insulation system

� No sleeve insulation

� Silver plating standard

� Tin plating available

� Porcelain or glass polyester standoff

insulators

� Molded vinyl boots with re-useable

hardware

� Catalog number embossed on each

boot to make reordering easy

� No tape used


PT Compartments

� One to three potential transformers (PTs)

� In SafeGear, less than 40kA duty is 19 inches high. 40kA and 50kA duty is 38 inches high

� Closed door racking in and out adds element of safety

� Drawout construction with extension rails makes the compartment easily accessible

� Lift truck not required to replace fuses

� Delrin snuffer contact technology


CPT Compartments

� 15 kVA, single-phase, truck mounted

� Larger size CPT’s are fixed mounted in

the rear compartment

� Fuse truck with fixed mounted CPT

� Closed door racking adds element of

safety

� Drawout construction with extension

rails makes the compartment easily

accessible for fuse replacement.

Compartment is 38 inches high

� Lift truck not required to replace fuses

� Delrin snuffer contact technology


Arrangements


SafeGear Arc-Resistant Switchgear

� Enhanced safety for personnel and

equipment

� Flap/vent system to relieve pressure

� Patented collection chamber

� Gases are safely expelled out the roof

through the plenum

� Built to EEMAC G14-1 1987 type B and

C construction and IEEE C37.20.7-2007

Types 2, 2B, 2C and 2BC

� More than 25 years experience in arc-

resistant switchgear

� Design allows for flexibility in

configurations and promotes superior

safety performance

� Certified by an independent test lab


SafeGear Demonstration


ONE-HIGH 1200A 1200A W/2 VT UNITS TWO-HIGH 1200A

1200A W/FUSED CPT 2000A W/1 VT UNIT ONE-HIGH 3000A

Location of Flaps and Vents in SafeGear


SafeGear Patented Internal Collection Chamber


SafeGear Construction

� Breaker doors secured with heavy

duty hinges and bolts

� Multi-point handle and latching

available

� Double thickness of steel

� Gasketed construction

� Seals gases inside

� Lexan arc-resistant window –

largest in industry – allows the

operator to check position and

status of circuit breaker without

opening the cell door


Plenum Benefits

� Channels gases out of PDC

� Provides room for flap operation

� Allows gases to expand

� Protects cable trays

� Maintains weather protection

� Allows lower building height

PlenumPDC ceiling

PDC Aisle

Two-high SafeGear


Plenum Design

� Sealed duct across top of switchgear, covering all vent flaps

� Sized and shaped to minimize turbulence and back-pressure

� Allows room for cable trays and conduit entry

� Channels gases safely out of building, through wall penetration and

vent


Plenum End Flap

� Flaps normally

closed

� Opens with pressure

in case of arc fault


Circuit Breaker

� Closed door racking to all positions adds element of safety

� Three position breaker

� Positive stop in all positions

� Breaker positively latched in the compartment (Disconnect)

� Racking mechanism is integral to the breaker element

� Auxiliary switches are breaker-mounted and wired out through the secondary disconnect, eliminating the need for separately mounted mechanism operated cell switches

� Front access mechanism

� Centered racking mechanism for easy alignment

� Embedded pole design


ADVAC® Circuit Breaker

Manual open andclose push buttons

Non-re-settableoperations counter

Open/close indicator

Racking access port

Manual springcharge port

Spring chargestatus indicator

Cell locking tabsand handles

Racking release lever

Racking padlock provision forlockout and safety procedures


ADVAC® Circuit Breaker

Precision cam

On-board auxiliary contactseliminate the need for cell-

mounted MOC switches and

related mechanical linkages

� 4a, 4b standard

� 9a, 8b optional

Auxiliary switchoperating shaft

Main drive shaft

Charging

motor

Toroidal

spring

Close &trip coils

Simple, front-accessible operating mechanism

and control components


AMVAC Circuit Breaker

� Operating mechanism rated for 100,000 operations

� 10 times ANSI requirement

� Interrupter assemblies rated for 30,000 full load operations

� Virtually maintenance free (minor lubrication needed)

� Only seven moving parts

� 90% less parts

� Permanent magnet for holding force and latch

� Dual capacitors store energy

� Full operation for up to 90 seconds after loss of control power

� Interchangeable with ADVAC


AMVAC Circuit Breaker 1. Upper Primary Terminal

2. Vacuum Interrupter

3. Epoxy Potting Compound

4. Lower Primary Terminal

5. Flexible Connector

6. Wipe Springs

7. Insulated Pushrod

8. Jackshaft

9. Stroke Adjustment

10. Position Sensors

11. Close Coil

12. Permanent Magnets

13. Armature

14. Open Coil

15. Manual Opening Actuator

16. Mechanism Enclosure


AMVAC Circuit Breaker

Manual opening mechanism

Auxiliary contacts

Sensor for switching position detection

Magnetic actuator

Electronic controller

Electrical energy storage


AMVAC vs. ADVAC

� AMVAC’s simple design reduces moving elements and the need

for spare parts


Accessories

� Racking crank, manual close bar

� Test cabinet

� Test jumper

� Ground & test device

� Electric racking device

� Lift truck

� Ramp

� Shutter actuator truck

� Breaker release handle

� Wear test device

� Dummy circuit breakers

� Slow close device

� IR Viewing Ports


Arc Flash Mitigation Relays

REA 101 Arc Protection Relay

� Fast trip time (< 2.5 ms)

� Unique fiber optic sensor technology

with self supervision

� Current supervision for secure and

reliable arc detection

� Easy to configure via front mounted

dip switches

� Suitable for existing LV / MV

switchgear installations or new applications

� Minimize potential risk of injury or

death while increasing reliability

� Includes standard 12 year warranty


Arc in the right bus

compartment with the

tie breaker open

Right REA 101 detects

overcurrent

Right REA 101 detects light

REA 101s send the current

information to all connected

unitsRight bus is disconnected

REA Application Example #1

REA

101

REA

101

REA

105REA

105

REA

105

REA

105


IR viewing Ports

� SAFE: Successfully Arc-Flash tested in accordance with IEEE C37.20.7

� RUDGGED: Certified by UL, SIRA and Lloyds of London for installation

into both indoor and outdoor equipment

� FLEXIBLE: Broadband optic suitable for all IR cameras.

� SECURE: Unique mounting system allows for safe, single person

installation & retro-fitting with No

dangerous internal fasteners required.

1. Eliminate need to enter the switchgear

while energized.2. Frequent

monitoring possible

without impacting production.

3. Easy to use system requires little

training


Product description

� Applicable to any unshielded medium voltage system – from 3 kV to 36 kV

� For permanent installation – information

on voltage presence available all the time

� Outdoor and indoor application

� Good visibility under all lighting conditions

� Maintenance free; passive device – no power supply needed

� Simple and robust construction –

resistant to overvoltages

(does not use electronic elements)

� Very compact construction

� Easy to install

� Economical solution

Indicator of voltage presence

installed directly on bus bars,

conductors etc.

Advantages of VisiVolt™


In Summary

� Advance & SafeGear available at 5 and 15kV

� SafeGear arc-resistant switchgear – Types 2, 2B, 2C and 2BC –

provide the highest level of personnel protection

� AMVAC breaker

� 100,000 mechanical operations mechanism

� 30,000 load break operations interrupter

� Virtually maintenance free

� REA Relays

� Protects you personnel and equipment with the most advanced arc

flash mitigation relays on the market.


��

february 2008 mv metal-clad...

Documents