[Al Skierkiewicz]

Oz,
I made the suggestion to try and diagnose the issue. If the PDP cannot handle the current then it cannot handle a CIM either. Connecting to the PDP through a 20 amp breaker for testing at least gives some electrical protection. We need to know where to look to suggest a fix.
Blocking the output port cannot not provide the necessary testing as it simply forces the piston to bypass compressed air. I would suspect that run current would only rise slightly in this condition. I am guessing that what is at issue here is a low voltage condition that is overheating the compressor armature.