I am surprised no one had a reply yet.
I would place PSX-AC on the output side of the TIU with the choke. Also, the PSX_AC default setting is ~4.8A
I don't recall if the PSX-AC includes voltage spike protection(TVS) If not, add one on the output of the PSX-AC.
I would call the MTH block "buss blocks" since that how it is configured. One in, multiple out for both hot and common.
The meters should be right after the power source. The fact that the 180PH would break first may be that you have raised the default setting in The PSX-AC or the breaker in the 180 is faster acting.
The ammeter would be the culprit. Is it self-contained or does it need an external shunt? It adds a very small amount of resistance to the circuit.
I think it should be 180PH>meters>TIU input>TIU output>PSX-AC>TVS>Track or add a set of meters on each output of the TIU>PSX-AC>TVS>Track in addition to monitoring the 180PH output.
Why does the TPC need to be there?
Need GRJ, Stan or Cjack to explain the why on the pass through with the one configuration that you used. I am still not sure what the ammeter will do to the DCS signal.
