So i recently adopted a older snapon compressor built by big red. 7 hp baldor motor.anyways had an electrician over to help install 220 and test parts of compressor.So when we hooked it up it would start but never run. He did a continuity test on the motor leads and it showed continuity which worried him (and me) At first he thought the contactor was faulty but being an electrician and not a compressor specialist he was unsure. Any advise would be greatly appreciated.
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compressor help
- Thread starter Blake150
- Start date
MacMcMacmac
Well-known member
Does it have the proper overloads installed? What do you mean by start but not run? It attempts to run but just hums? Starts to turn then stops? Pumps up once then doesn't restart? 7hp is a hard pull for single phase 220v. Is this at home or in a shop? Is the tank empty? Is it in a cold environment? Does it have capacitors on the motor? Are they in good shape? Does it have a start winding with a centrifugal switch? Is it moving freely like it should? Did the contactor pull in like it should? What is the control voltage for the coil on the starter? Is there a thermal overload switch on the motor? Is it pressed in?
Many things could be wrong.
Many things could be wrong.
redmondjp
Well-known member
I have one of these compressors. Snapon claims that it has a motor starter, but it doesn't. It has a contactor controlled by a pressure switch (the contactor is well hidden underneath the mounting plate). There is no overload protection, other than a two-pole circuit breaker that is used as the on-off switch.