Emerson MONITORING OpenComms Manuel D’Utilisation

Two wiring harnesses are included with the retrofit kit, one for the 

power connection and the second for communications. They are of suf-

ficient length for use with the Deluxe System/3 and ICS units and the 

microprocessors listed above. For the Challenger product series, use 

the longer wiring harnesses included with the NIC-K-Chall kit.

The harness supplied with the OpenComms Network Interface Card 

(p/n 159084G1) is equipped with three connectors, one at either end of 

the harness and one in the middle. The harness taps power from the 

24 VAC input to the control board of the environmental unit. To con-

nect this power to the NIC:
1. 1. Locate the connector containing the two red wires plugged into 

P43 on the control board and unplug it. Reconnect it to the 

connector in the middle of the supplied harness.

2. 2. Plug one end of this harness into P43 on the control board and 

the other end into TB3 of the OpenComms card.

To connect power to the NIC, wire as described above. However, some 

field modification of the wiring harnesses is necessary for connection 

to legacy systems.
Level 0: Remove the power connector normally plugged into P43 and 

wire to terminal connections 1-5 (24V)/1-10 (ground).

NOTE
Board illustrations are shown only for location of connections. 

Do NOT tap power from the auxiliary 24VAC terminals T5/G5 

on the SM/AM/AG environmental controllers. Damage to 

controller and interface card may occur.