Multiple HPWCs: Communication Issue?

[Jillmark99]

It’s not a power supply issue. Both chargers will charge the cars perfectly fine in master mode.
I’ve thrown in the towel. I’m not one to give up either but I’ve wasted enough time on this one. LOL.
thanks for everyone’s help with this. It’s greatly appreciated.

 

[ajdelange]

This probably isn't going to help much but the marking "RS-485" tells you that communication uses that protocol which you can look up. This will tell you something about the signalling, the voltage levels etc. With a volt meter you might learn something - with an oscilloscope even more. There should be a small voltage across the + and - terminals and, clearly, when hooked up properly, that should be the same at both ends. In addition to which there should be a small voltage between the + and - terminals when the wires are disconnected. This assumes that the gear has the sort of standard pull-up/pull-down terminating network which it doesn't necessarily have. You could also power down, disconnect the comm wires and check the impedance between the two terminals. It should be about 100 Ω. Again that depends on the terminating network, if any, but whatever the case the two units should be the same. Clearly a dead short between the terminals would be a clue.

 

[Dithermaster]

My manual also says (on p. 29) "Set one Wall Connector as the master by setting the Rotary Switch Position from 1 to 8 depending on the maximum available output current." Apparently newer manuals fix this, but did you try a setting like 8 instead of A?

I did confirm it should be "plus to plus" and "minus to minus" so that looks right.

You said that when the comms are disconnected and both units are set to master that they both work, so the hardware and power seem good.

I think you need someone to loan you a third Wall Connector (of same type) that you can try with both to see if the comms are broken on one of them.

They both should have a warrantee, so take them in to Tesla and have them test them.

 

[Jillmark99]

It turns out the issue was something inside the charger I was using as the slave charger. I removed the slave charger and replaced it with a different Gen2 charger (swapped it with a friend that only has one charger) and the master/slave setup now work fine.

The old Gen2 charger I was using works fine on its own just won't work in a master/slave configuration. Strange. At least now its working as it should.