Alarmline Linear Heat Detection

Linear Heat DetectionTemperature Related Risk Protection

• Data supplied by fire insurance companies indicates that most industrial fires are caused by

- Friction heat & sparks

- Overheating of equipment

- Spontaneous combustion

- Oil & oil fired equipment.

What is Linear Heat Detection?

• Continuous heat detector in the form of a cable

- Alarmline Analogue: averaging heat detector

- Alarmline Digital: fixed temperature heat detector

What is Linear Heat Detection?

• Cable-type Sensor– “Point of Risk” Detection Method

• Detects Heat From Fire– Last stage of fire

• Typically used where smoke, flame or other detectors are not an option

Stages of Fire

Analogue LHD Cable

• Definition:

- Multi-conductor cable containing insulators whose resistance varies proportionately to changes in temperature

- Re-settable provided temperature does not exceed burn-off point of PVC coating

- Alarm level adjusted via controller.

- Allows testing without damaging cable

Alarmline Analogue LHD Cables

• High resistance - standard applications

• Nylon extruded - chemical resistance

• Bronze braided - increased mechanical protection over standard high resistance cable

• Stainless Steel braided over nylonextruded cable - offshore applications.

AlarmLine Construction

• 4 conductor 0-46 mm dia copper cable– Two conductors for heat sensing– Two enameled conductors for continuity– Twisted at 30 turns per foot to cancel potentially high

voltage inductance

How Does AlarmLine Work?

• Sensor cable has negative

temperature coefficient

insulation

• Temperature increase

exponentially lowers cable

resistance PROTECTIVE INSULATIONHIGH TEMPERATURE PVC

SENSOR CONDUCTORWIRE

NEGATIVE TEMPERATURECOEFFICIENT (NTC)

Alarmline LHD 4 Controller

Alarmline LHD 4 Controller

- Alarm level adjusted via moveable link

- Open circuit and closed circuit fault monitoring

- Fire and fault output to conventional fire alarm panels

- Volt-free relay option for analogue addressable fire alarm panels

- Eurocard 19” rack option.

- Allows quick system adjustments without cable or hardware change.

AlarmlineNomogram- Select the sensor cable

length being used (D)100m

- Mark the Max Temperature where an alarm must not be given (B) 45 degrees

- Draw a line from point on “D” through point on “B” to the switch setting line (A). This is the switch setting that will not give a false alarm at the Max ambient temperature.

AlarmlineNomogram-In the event of a hot spot

occuring, it can be shown how hot this would need to be to give an alarm for a given length

- 10 metre length = 83 degrees

- 1 metre length =120 degrees.

Intrinsic Safety Barriers

• For Class 1, Div 1, Groups A, B, C, D classified areas

• Each IS Barrier handles two conductors

• Use two IS Barriers per sensor cable

• Use enclosure to insure grounding

Intrinsic Safety Barriers

Safe area Hazardous area

Inte

rface

Mod

ule

Junction BoxIS Barrier

Reference: AlarmLine Manual

Up to 255devices

PSD

Typical Intelligent Application

Addressable RxTx Loop~1000 Metres26 Ohm, 0.25uF

AlarmLine Sensor

AI AOCPD

LHD LHD LHD

AO AO AO

24v PSU 24ov

Standard 4 core cable

Hazard

2 WireInterfaceModule

Typical Conventional Application

AlarmLine Sensor

KiddeControlPanel

Standard 2 core cable

Max (1,000 m)

JunctionBox

Alarmline LHD - Advantages

• Flexibility

- Mechanically

- Electrically

• Durability

- Wide range of casings / braiding within both analogue and digital cables.

- Operating range -65º to +200º C

- Unaffected by operating environment.

Digital LHD Cable

• Definition:

- A cable which contains an insulator which melts at a specific temperature

- Switch output provided once alarm temperature is reached

- Not re-settable.

Alarmline Digital LHD Cables

• Polythene braid 70º C (158º F )

• Nylon over sheath 70º C (158º F )

• Polythene braid 90º C (194º F )

• Nylon over sheath 90º C (194º F)

• PVC 105º C (221º F )

• PVC 174º C (346º F )

• Fluoropolymer 227º C (440º F )

Internal

Internal / External

Internal

Internal / External

Internal / External Protected

Internal / External Protected

Internal / External

LHS Digital Cable Construction

Alarmline Digital Control Units

• Firebeta conventional panel with optional extinguishant release module

• Any other conventional fire alarm panel and/or extinguishant release module (retrofit).

• Any analogue addressable control system

Addressable vs. Hard-WiredZONE A ZONE B ZONE C

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MP

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LHS

Hard-Wired System

Addressable vs. Hard-Wired

ZONE A ZONE B ZONE C

MPMP

To

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ga

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stem

MP

To

Ad

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AILHS

RxTxLine

Addressable System

Analogue & Digital Comparison

Alarmline Analogue Alarmline DigitalAnalogue DigitalRecoverable Non-recoverableOpen & Short Circuit Fault Detection Open Circuit Fault DetectionMin operating temperature -65 C Min Operating Temperature -65 CMin Alarm Temperature 35 C Min Alarm Temperature 61 CMax Alarm Temperture 105 C Max Alarm Temperture 238 CMax Re-coverable Alarm Tempurature 150 C N/AMax Length 1000m Max Length 10,000m

°

°°

°

°°

°

International Approvals

Alarmline (Analogue) Alarmline (Digital)

UK power generation- 5117 P 11- EPA 022/215

Factory Mutual- OB 9A2.AY- OR 5A4.AY

Chinese Fire Officers- MAAL 96652

Chinese Power Generation- NSTCFEPQ (Appr) 92005

German VdS (1995)

UK power Generation- EPA 019-021- EPA 206/220

Factory Mutual- OD 6A9.AY- 300 5155- 300 3834

Chinese Fire Officers- MAAL 96652- 300 8312- 300 8933

Alarmline - The Competition

• Digital systems

- Protectowire (USA)

• Analogue systems

- Patol Firesense (UK)

• Fibre optic systems (UK)

- York Sensors

- Siemens.