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 Himod unit.

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

other end into TB3 of the OpenComms card.

The second wiring harness provided (p/n 159083G1) has a connector 

fitted at either end and is the communications connection between the 

unit microprocessor and the NIC.
To put it in the system:
1. Remove the existing wire located on P25 of the environmental 

controller, cut off the red connector and reconnect the wires to TB2 

of the interface card. Ensure correct polarity.

2. Connect one end of the wire harness to TB1 of the interface card; 

the other end connects to P25 of the environmental controller.

An enclosure is recommended for use with ceiling-mounted environ-

mental units or where internal mounting of the Network Interface 

Card is not feasible. Older-generation Deluxe and Challenger units 

may also require external mounting.

NOTE
Board illustrations are shown only for location of connections.