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29/11/2017
CM2M-K
The CM2M-K is a current monitor designed for use with Medem ventilation interlock systems (main panel). It’s is connected via a
6 core low voltage cable.
There is a 12volt supply for the CM2M-K (from the main panel) the CM2M-K then provides 2 NC contacts L/B & LA for connecting
to the main panel terminals S1 & E1 .
Each CM2M-K can be used to interlock 2 fans (sides A & B), the fans are connected by taking the live feed for each fan through
the “Live In and Live Out” terminals (before any speed controllers/inverters), fan load sensitivity range on each fan is 30 milliamps
to 24amps.(max).
There are 3 LED indications,
1x Green, for the 12 volt power to the CM2M-K
2x Red, one for fan A and another for Fan B load detection.
When the fans are switched on and the load is detected (see sensitivity adjustment) the corresponding side’s NC contact (L/B or
LA) will close and the red LED will light, this will flash for the first 15 minutes after current detection and then become solid. The
flashing LED helps to identify a fan intermittently stalling
Terminal Connections
The LB & LA terminals correspond to each side of the current monitor and provide a closed
contact, connect these back to the S1 or E1 terminals on the main panel.
Please note that when using more than one CM2M-K the signal connection should be in series.
Connect the 12 volt terminals back to the main panel 12v supply.
Fan A
running LED
PCB Connections
Connections at the current monitor
Fan B
running LED
Power LED
Description and Operation
FAN A
Live Supply
FAN A
Speed Controller
