Merlin CT1200S
User Guide
Rev: 03 05-23
4
2
Circuit Board Terminals
2.1
POWER IN
A 110-240VAC electrical supply should be externally fused at
3A and connected to the terminals marked [POWER IN LNE].
2.2
TO VALVE
The 110-240VAC output to a gas solenoid valve should be
powered using the terminals on the CT1200S detailed [GAS
VALVE LNE].
2.3
TO BMS
Connections to Building Management systems.
This is a relay that changes state in alarm or when gas is on/off and other
external relays that affect other devices and controls such as purge fans,
audible alarms etc.
Detailed on the circuit board as [BMS OUT] normally closed (N/C), common
(COM) and normally open (N/O). These are volt free connections.
2.4
EM REMOTE
The terminal for remote emergency shut-off buttons is detailed on the
circuit board as [EM REMOTE].
These connections are linked out as a factory setting.
Remote emergency shut-off buttons should be volt free and wired to the
CT1200S.
2.5
FAN PD SWITCHES
These terminals are used to receive an input signal from external air
pressure switches or external current monitors.
These are linked out as a factory setting as shown.
Wiring to switches & current monitors should be made using two-core
volt free connections.
If only one fan is being used in Mode 1 (see 3.5) the terminals not in use
should be left linked out.
If only one fan is being used in Mode 2 (see 3.5), pressure switch or current monitor should be
wired into both, Supply and Extract terminals.
