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9

Gas detectors usually fall into two groups for placement

Each site should be surveyed and assessed on its own merits. This document presents general 
guidance only. 

1. Plant Protection. Typically flammable gas detectors fall into this category. Aside from asphyxiation 
flammable gases are typically not directly toxic and so detectors are placed strategically where the gas is 
expected to accumulate based on its relative density to air (lighter or heavier)

Note that in many cases both life safety and plant protection sensors may be appropriate on a site. For 
example a plant using liquid helium may have plant protection sensors at high level to ventilate roof 
spaces in the event of leaks. However in the event of ventilation failure Helium could accumulate down 
towards the zone where personnel operate. In this case a second set of life safety sensors would be 
appropriate.

2. Life Safety Systems. Here the concern is that a toxic or asphyxiant gas is directly hazardous to 
personnel and so the gas detection is placed based on the normal operating zone for the people present

Lighter than air gases, detectors placed at highest ceiling points
Consider fitting collector cones at lower level for gas bottle stores
boiler plant and gas meters (see separate application note).

400mm

1000mm

1800mm

Life Safety Zone

Consider ceiling divisions, follow rules for smoke detectors

Methane, Helium, Hydrogen, Ammonia etc

LPG, CO2

CO, CO2, O2
H2S, NO2, NO
HCN, HCL, HF
NH3 etc

Consider fitting splash/dust guards to protect low level sensors

Consider sensors in under floor areas/voids/drains where heavier than air gases are present

LPG

0-100%LEL

SN:20235-1-1  ADD:4110

GAS DETECTOR

LPG

0-100%LEL

SN:20235-1-1  ADD:4110

GAS DETECTOR

Siting Gas Detectors

Содержание 2-Wire Systems

Страница 1: ...a l l e r s G u i d e V 4 5 1 Triton House Crosby Street Stockport SK2 6SH England T el 44 0 161 483 1415 Fax 44 0 161 484 2345 Email sales internationalgasdetectors com Website www internationalgasde...

Страница 2: ...First Fit Cabling Fit Detector Nodes Fit Additional Devices Where You Need Them Safety Assured CO H2S LPG 4 20 Addressable 2 Wire HUB APP Based Setup and Service Tools No Speci c Cable Type No Cable P...

Страница 3: ...equired and can also provide training for surveyors specifiers designers and installers This installers guide is intended for the use of system specifiers surveyors designers and installers The intent...

Страница 4: ...3 SECTION 1 MOUNTING DETAILS FOR EQUIPMENT...

Страница 5: ...5mmSQ See IGD Cable System Calculator Typically SWA MICC FP200 SY CY H03VVH2 F Mains Cable Screened screened or Similar Note 150W and 24V DC Versions Can be Flush mounted into walls up to the front f...

Страница 6: ...5mmSQ See IGD Cable System Calculator Typically SWA MICC FP200 SY CY H03VVH2 F Mains Cable Screened screened or Similar Addressable 2 Wire Note 150W and 24V DC Versions Can be Flush mounted into wall...

Страница 7: ...128 0 The ATEX version uses IGD s JB3 series ATEX EXD terminal enclosure Please note that cable glanding and sealing must conform to ATEX requirements which is more fully described in the ATEX JB3 man...

Страница 8: ...tom Face Side Face 56 5mm 30mm 10 o 20mm Cable Entries 360mm Battery Backup Modules TOC 750 BAT1 7AH Battery Backup with 150W PSU TOC 750 BAT2 17AH Battery Backup with 300W PSU 460mm 292mm 115mm 20mm...

Страница 9: ...8 SECTION 2 SITING GAS DETECTORS...

Страница 10: ...owards the zone where personnel operate In this case a second set of life safety sensors would be appropriate 2 Life Safety Systems Here the concern is that a toxic or asphyxiant gas is directly hazar...

Страница 11: ...uation Alarms 5M is a Maximum Detection Distance and Will be E ected by Topography Gas Levels Will Drop as Distance to Leak Source Increases Requiring Lower Alarm Set Points Siting Gas Detectors Heavi...

Страница 12: ...ally cooled gases can typically be at lower temperature and high density than their surroundings they will behave di erently than when in their gaseous state In such cases it should be considered if t...

Страница 13: ...ector Mounting Positions Safe Area BS EN 50194 Detectors should be mounted vertically with the sensor face facing downwards to protect from contamination Sensor Facing Down Sensor Mounted to Vertical...

Страница 14: ...to or Away From the Sensor Face This Situation May Result in Contamination and or reduced Detection Capability Air Flows up to 6M S Are Allowable Without Any Performance Issue Across the front of The...

Страница 15: ...abling Another option is to t IGD s range of annunciators Audio Visual alarms Annunciators are addressable devices typically tted at door entry points They provide a clear audible visual alarm in the...

Страница 16: ...15 SECTION 3 GENERAL CABLING PRINCIPLES CABLE TYPES AND CABLE SIZING...

Страница 17: ...e the drain wire is insulated with suitable size sleeving and terminates to the cable screen terminal SWA style cables are usually only recommended for used with ATEX EXD housings where the universal...

Страница 18: ...NOT lever them off This will potentially cause damage to the PCB and or connector mating parts and invalidate any warranty If it is necessary to remove the PCB connectors use long nose pliers Note th...

Страница 19: ...rs For Door Entry Control Use Annunciators with Gas Detector Interfaces to Detect Alarm in Specific Areas Use the Detector or Annunciator I O Capability to Control Gas Supply Valves Beacon Sounders or...

Страница 20: ...and slave systems The Tocsin 750 series controllers have an in built memory map allowing access to alarm status panel status readings etc using Modbus RTU protocol Wiring between units is as follows...

Страница 21: ...rs Will Prevent System Operation Tocsin 750 Series Annunciator Modules are interconnected as follows using two core cable The system is designed to operate using screened cable In some circumstances f...

Страница 22: ...0 500 1000 Length M 32 30 32 32 Toxic 21 30 Pellistor MK6 7 32 16 20 14 Pellistor MK3 25 11 Booster Module Required For Increased Detector Nodes Beyond Indicated Numbers 2 1 5mm Cable 15AWG 750 1000 L...

Страница 23: ...22 SECTION 4 MAKING DEVICE CONNECTIONS TO DETECTOR NODES...

Страница 24: ...r Own Approvals 300W 2 o 5AH Lucas Gell Lead Acid Batteries Fitted as an option where battery backup required 7 Colour Touch Screen HMI Display Option 1 750 Display Option 2 650 635 2 x 8 RGB LCD and...

Страница 25: ...re switched mode types Note dependent on PSU type the incoming voltage may require to be set using a switch setting between 110V AC and 230V AC If this is the case note the current switch setting indi...

Страница 26: ...3 104 5 6 Device Address Table Note that one 2 Wire addressable highway running Sentinel protocol can support up to 32 modules Each module can have up to 8 connected devices IGD Con guration software...

Страница 27: ...put Digital Input Pellistor Port Sounder Display Comm Port 3 6 2 1 5 4 7 0 55 Deg C IGD 2 Wire Highway Operating IGD Sentinel Protocol 85dB Option for TOC 750 Annunciators Supports IGD Infra Red PID T...

Страница 28: ...ed to be amended so the channel reads and scales correctly and so that alarm levels are appropriate The most commonly supplied detector node comes pre fitted with a gas detector The detector front ass...

Страница 29: ...oiler shut down interfaces or similar When switching external loads it is important to consider the nature of the load being switched For inductive loads suitable protection from induced back EMF must...

Страница 30: ...an result in damage to the output Ensure relay coil is rated at 24V DC and Max 100mA or Min 240 Ohms Do not exceed 100mA Load Port 1 and Port 2 I O Port 1 I O Port 2 Wiring to I O Port 1 and 2 Each De...

Страница 31: ...Treated as Off Anything Greater is On If You Are Wiring Digital Inputs 0V Option Allows Logic inputs from External Devices Wiring to I O Port 1 and 2 TOC 10 Unit 1 TOC 10 Unit 2 External System V 4 2...

Страница 32: ...lowing diagram indicates tting the cable and eld wiring to a volt free contact 3 1 Pulse 0 01M The Solid State Input Will Accept up to a 0 2 Hz Pulse Train Input From a Gas Meter or Similar Device Wit...

Страница 33: ...s loop powered PN TOC MA ISO I O Port 1 I O Port 2 Wiring to I O Port 1 and 2 a For a 2 Wire Loop Powered Device 4 20MA 24V Option b For a 2 Wire 4 20mA Device Externally Powered Device 4 20MA 0V Opti...

Страница 34: ...Head Current Volts MK3 ATEX EXD IIC T6 360mA 2 2V MK6 Safe Area 170mA 2 5V MK7 Safe Area 170mA 2 5V In operation and with zero air applied correctly to the detector the balance between the two detect...

Страница 35: ...34 SECTION 4 Control Panel Interfaces and Connections...

Страница 36: ...ds can be cascaded to add more ports if required Two display options either 650 style with jog wheel Note both displays can be tted at the same time which can allow the HMI display to be remote from t...

Страница 37: ...nnels on the control panel switched inputs 1 and 2 volt free contacts Normally Closed Loops Opening on Alarm 0V DC 24V DC A1 A2 Example fit protection diodes when switching external DC loads 1N4004 Di...

Страница 38: ...fault as relay O P 107 after a FIND operation Two display option are available A 2 x 8 RGB LCD supplied as standard on the 650 model and a colour HMI touchscreen supplied as standard on the 750 model...

Страница 39: ...ard relays number from this one Base Address set up LED s and interface for the relay card In all Cases Relay contact ratings 5A 250V AC Non Inductive 5A 30V DC Non Inductive Spike suppression must be...

Страница 40: ...d Based Detectors Relay cards also have analogue and digital inputs that can be used to read data onto the system from external devices Setup of the inputs type range addressing etc is controlled via...

Страница 41: ...s systems can be up to 3KM long In this example the main master panel at the start of the cascade will see all the detector nodes and relay cards installed on panels below it L2 IMPORTANT NOTE Ensure...

Страница 42: ...llow then external battery backup units can be employed OR 650 or 750 Series Controller TOC 750 BAT1 7AH Option 150W PSU TOC 750 BAT2 17AH Option 300W PSU Note that the main control panel needs to be...

Страница 43: ...1 73 13 2 17 7 1 89 2 52 1 64 1 1 1 24 Max Power in Watts 1 4 25 Device Loadings for Battery Backup Run Time Calculation Indicated power is with the device in full alarm with all its I O points energi...

Страница 44: ...system This may be due to the cable size being too small resulting in a large volt drop over the cable run or that there are a large number of devices drawing power Booster modules are mains powered a...

Страница 45: ...urposes a power cable is de ned as above 50 V AC with a 10 A rating Power and gas detection cables are installed with a 200 mm separation wherever possible Where 200 mm separation isn t possible then...

Страница 46: ...lable as an Option to Match Control Panel Screen Display Location Tags If Required Order as TOC TAG A and supply Table of Required Tag Descriptions Cabling Fitted to Tray Using Stainless Steel Cable T...

Страница 47: ...Control Panel Screen Display Location Tags If Required Order as TOC TAG A and supply Table of Required Tag Descriptions Cabling Fitted to Tray Using Stainless Steel Cable Ties Gas Detection Cabling Mo...

Страница 48: ...C TAG A and supply Table of Required Tag Descriptions Gas Detectors Mounted Above Below Dado Style Wall Trunking System Ensure Segregation From Mains Cabling Ensure Cable is Only Run in Trunking Data...

Страница 49: ...sure Cable Screens are Correctly Terminated and cables are stripped to the enclosed guide See Cable Calculator for Cable Core Size vs Distance VS Number of Devices Cable Screen or Drain Wire Tubing 6...

Страница 50: ...k unburnt gas if the supply automatically re instates By fitting a no volt release module to control the power to the gas valve this then requires manual re set of the supply before it is re instated...

Страница 51: ...50 Notes...

Страница 52: ...sby Street SK2 6SH Tel 44 0 161 483 1415 E mail sales internationalgasdetectors com International Gas Detectors Ltd Triton House Stockport United Kingdom Website www internationalgasdetectors com Manc...

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