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.
