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Mini Merlin Installation, Operation & Maintenance                                                                                                                              

 

Rev: 01 02-22 

8  

APPLIANCE LIMIT CIRCUIT 

 
 
The device can be used to directly shut down a 
gas appliance when a fault condition is detected 
(gas leak) by wiring terminals of one BMS into the 
low voltage safety limit circuit of the appliance.  
 
 
 
 
 

 
 
To connect both BMS to the safety limit circuit of an appliance - wire in series. 

 

 

If dangerous levels of gas are detected or the mini merlin 
encounters a power failure, the circuit is opened, disabling the 

appliance.  

Multiple appliance limit switches can be wired in series

 

 

 

 

 
 

 
 
ADAPTABLE OUTPUTS 

The mini merlin can be used to effect external relays and contactors to disable multiple appliances when a fault 

condition is detected. Multi-pole relays can interrupt power to electrical circuits controlling boiler, valves and pumps

 

 

 

Low voltage wiring is to be inserted into the external limit circuit of a gas appliance. 

The diagram shows a 240VAC general purpose primary coil with two sets of switches, each with 
 
Normally Open (NO) and Normally Closed (NC) contacts. These contacts are rated for up to 12A AFL. They can be 

used to break a low or line volt limit circuit or completely remove power to an appliance. 

 
 
 
 

Содержание Mini Merlin TFT CH4CO v2

Страница 1: ...TFT CH4CO v2 Dual Gas Detector Installation Operation Maintenance Manual Please read this manual carefully and retain for future use For specific requirements that may deviate from the information in this guide contact your supplier Oceania Gas Safety www oceaniagassafety com ...

Страница 2: ...ng Cabling 6 Circuit Board Overview 7 Wiring 7 Auto Reset Buzzer Switches 9 Building Management System 9 Operation 10 Initial Power Up 10 Digital Indications 10 Alarm Set Points 10 Manual Reset 10 Remote Shut Off 10 Manual Circuit Simulation Test 11 End of Operational Life EOL 11 Maintenance 12 Cleaning 12 Manual Circuit Simulation Test 12 Bump Test Gas Response Check 12 Bump Test Procedure 13 Spe...

Страница 3: ...th specific medical conditions If in doubt consult a doctor physician Your product should reach you in perfect condition if you suspect it is damaged contact your supplier Warranty Statement Warranty Coverage The manufacturer warrants to the original consumer purchaser that this product will be free of defects in material and workmanship for a period of two 2 years from date of purchase The manufa...

Страница 4: ...ly ventilated Automobiles gas stoves water heaters portable fuel burning heaters fireplaces Blocked chimneys or flues corroded or disconnected vent pipes Burning charcoal or fuel in grills in an enclosed area or near the home Methane General Information Methane is non toxic and it can be harnessed as an energy source However methane is highly explosive and it can cause death by asphyxiation Methan...

Страница 5: ... positions determined by those who have knowledge of gas dispersion the process plant system and equipment involved and in consultation with both safety and electrical engineering personnel Take in to account the design of the air flow patterns within the zone area Detectors should be installed in the correct orientation as recommended by the manufacturer and ease of access should be accounted for...

Страница 6: ...g electrical box Restrain the hazardous live wiring from accidental loosening to prevent wires from moving after installation and touching parts of opposite polarity or at low voltages Isolate the equipment from all hazardous live power sources before opening the cover 1 Carefully remove the front cover from the unit by using an M3 socket wrench 2 Using the rear base mark mounting holes to the wal...

Страница 7: ...lamping or barrier For field connections other than connected Heat detectors use wires suitable for at least 167 F 75 C Wiring GAS VALVE We do not recommend installing a gas solenoid valve with standing pilots A gas solenoid valve should be powered using the terminals marked VALVE OUT When the valve out terminal is wired to a normally closed NC gas solenoid valve the device can be used to isolate ...

Страница 8: ...liance Multiple appliance limit switches can be wired in series ADAPTABLE OUTPUTS The mini merlin can be used to effect external relays and contactors to disable multiple appliances when a fault condition is detected Multi pole relays can interrupt power to electrical circuits controlling boiler valves and pumps Low voltage wiring is to be inserted into the external limit circuit of a gas applianc...

Страница 9: ... wire the input in series with the relay output Auto Reset Buzzer Switches ON OFF Auto Reset In the event of a power loss the mini merlin will restart automatically when power is restored In the event of a power loss the mini merlin will need to be reset manually when power is restored This is the factory default condition Buzzer The buzzer will sound every 15 seconds during pre alarm and continuo...

Страница 10: ...etween the maximum MAX and the real time current value When the device has reached an alarm state the concentration indicator will remain red even if gas levels are safe until the device is reset by pressing the touch sensor once An audible buzzer will sound if the buzzer switch on the circuit board is on Target Gas Pre Alarm Buzzer Alarm Buzzer Carbon Monoxide CO 25ppm Beep every 15s 50ppm Contin...

Страница 11: ...mate from the first five 5 hours of continuous power The EOL will depend on the type of gas your detector is targeting and may vary depending on its application and environmental conditions such as the frequency of exposure to the target gas poisons or inhibitors The typical life of a gas detector depends on its application and intended target gas in addition the operational life can be prolonged ...

Страница 12: ...y briefly exposing the unit to a known concentration of the target gas that usually exceeds the highest alarm point If the detector goes into alarm and all signals outputs activate then the system is working safely If the system fails to operate as intended in an alarm state the gas detector must not be used until a full inspection and service has been conducted NFPA requires all gas detectors to ...

Страница 13: ...cylinder All cylinders will re seal upon removal of the regulator valve Deviating from this test process is deemed improper and may affect the functional safety of your device Exposure to chemicals smoke or any other materials other than the gases intended to be monitored can seriously damage the gas sensing elements Always allow a minimum of 5 minutes before testing the same unit 1 Ensure you hav...

Страница 14: ...Mini Merlin Installation Operation Maintenance Rev 01 02 22 14 Page intentionally left blank ...

Страница 15: ...c Equipment Overvoltage Category II Pollution Degree 2 Relays Volt Free BMS relay output 0 5A switching current resistive load Environmental Ingress Protection Not Formally Evaluated Operating 10 50 C 14 122 F 30 80 RH non condensing Storage 25 50 C 13 122F up to 95 RH non condensing Altitude Rating 2000m Wiring Typical Min 18AWG 75 C min Tinned copper Approvals Electrical Safety and Electromagnet...

Страница 16: ... performs as intended and is free from any unforeseen damage caused by transit installation Every effort is made to ensure the accuracy of this document however OGS can assume no responsibility for any errors or omissions in this document or their consequences OGS would greatly appreciate being informed of any errors or omissions that may be found in the content of this document For information no...

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