We are hoping to use 2 PCMs. However, our PDP only has space for 1. Here are our questions:
1)Can we have 2 PCMs? We cant find a direct rule against it.
2)How would we connect it since we only have one space on our PDP?
Yes, you can. Just hook the second one up to a 20A breaker through the wago terminals on the side.
^^ This. See the last row in table 10-3 in R59. You can put up to three PCMs on that leg (but remember that only one wire can be in the PDP WAGO connector per R56; you’d have to put a splice/splitter downstream)
I saw some recommended using a PCM instead of the hard to source spike relay to control there vision light ring. Do you think that would be a custom ckt and require it to be on a 20A from the PDP?
A vision light ring would be a CUSTOM CIRCUIT. Per R37, it can be controlled by a motor controller, R36B relay module, or PCM. It may also be controlled by another custom circuit (e.g. a relay module which is not in the R36B list). CUSTOM CIRCUITS may be protected by up to a 40A breaker; there is no minimum. Note that smaller breakers will allow you to run smaller wires.
If you mean that the PCM must be connected to a 20A breaker, while it is recommended that the PCM not be powered from the same port as the radio’s VRM, this isn’t really a requirement. Note that the PCM solenoid ports can only provide a total of half an amp - see the last row of the table at the top of section 1.2 of the PCM User Guide.
Added: checking AndyMark’s web site, their light rings draw 90-100 mA each.