sundance-communications.com/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems Key Lamp Module for M7324

I need to expand a M7324 with a Key Lamp Module. It seems like the model number I need to go with is NT8B41.

I've never seen this particular KLM in person, and am not sure how it works. I've looked to eBay for the item and notice some come with power supplies, some don't, and other mention nothing of needing one. Even some resellers online fail to mention the power supply or the need of one. The pictures I've seen of the power supplies just look like a transformer with two poles on the bottom of it.

Could someone explain if the power supply is needed and, if so, how I would wire it into the KLM.

Yes it's needed. Use 2nd pair to connect.

Thanks for your response.

Please excuse my ignorance: Just to clarify. I need to crimp the phone's two wires into the center pair and the + and - from the transformer into the 2nd pair of the RJ-11 plug?

That is correct. And more if you use a 2nd KLM.

Use a 4-wire line cord if one KLM.
Use a 6-wire line cord if two KLM's.

1 - +24v 2nd KLM
2 - +24v 1st KLM
3 - Ring Phone
4 - Tip Phone
5 - -24v 1st KLM
6 - -24v 2nd KLM

The cord goes from the wall to the 2nd KLM to the 1st KLM to the phone. Can be a 3 pair from the wall to the KLM, then a 2 pair from that KLM to the 1st KLM, then a single pair to the phone, don't all have to be 3 pair.

For simplicity if you have a Valcomm, they provide a 24v power out, Bell up here used to patch that to KLM's to power them quite often. Saves on the wall warts, as well you can always make a power injector with a jack and cord.