All:
I need your help. I have an interesting thing going on with a set of DZ-2502 push buttons. I have 5 DZ-2502s on a piece of fascia, as shown below.
On the other side of the fascia, these switches are all being fed 15VAC from a single pair of wire drops from a bus (through a terminal strip). As you can see from the track map, the switches are some distance from their respective push buttons. Switches 32, 33, 34, and 36 are installed and working; they respond to CAB-1 commands (TMCC).
What I Observed: Switches 33 & 34 would NOT respond to their respective DZ-2502.
My first thought was that the DZ-2502 was bad. Swapping the old one for a working one didn't change anything. Next, I thought the white push-button wire from the switch machine was broken. It was fine. In fact, I installed a DZ-2502 under the switch machine and tested it; everything worked perfectly.
What Cured the Symptoms: Finally, I created a separate 15VAC pair of drops from the bus to Switch 33. It worked. Switch 34 still wasn't working, so I gave it its own separate power drop. It's working too!!!!
My question: What's really going on here? Are we seeing:
- DZ-2502s drawing an unexpected amount of current and requiring their own drops? Is there a limit to the number of DZ-2502s I can have on a single drop? [This seems very unlikely to me].
- Is there a bigger switch bus wiring issue?
- Something else?
By the way, all 3 switch buses (42 switches in all) are powered by a single K-Line PowerChief 120F using it 15VAC taps.
I would be grateful for any insight from our electrical whiz-kids on the forum. I've cured the symptoms, but not sure I fixed the problem.
Thanks,
George
