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by Tommy
(MS)

CWC200ST 3hp 4gal. twin tank. The compressor is plugged into power pole on a 20 amp breaker, no extension cord is in use.

With the tank empty turn compressor on, it will reach about 30 psi and then will throw the reset. Wait couple minutes push reset and it will them pressure up to around 60 psi and throw the reset again. Does this again at around 90 psi and then finally reaches 125 or 130 psi at normal shutoff.

I have checked and adjusted pressure switch, have checked the pressure relief valve, and checked the valve that allows air into tank.

I don’t know what to do. It should not be the capacitors or pressure switch as it starts fine, and the pressure switch also shuts it off around 130 psi.

I started to bypass the reset but did not want to ruin something else. This has been in the shop twice and they say they can’t find what’s wrong. Any help would be much appreciated. Thanks, Tommy


Tommy, if the start / run capacitor on your is weak, that could account for the compressor issues you are facing.

I the start / run cap builds a bit of a charge which is used to get the motor going, but the motor lacks the power supply needed to keep going against a building pressure, the motor overheats as it’s struggling, and as a result it kicks off the compressor motor thermal reset.

See the page about checking your caps on this site, and see if that is the problem, won’t you? Then add a comment if you still need some help.