The overload protection has to be reset frequently to build pressure
by James Waldron
(Pierre Part, LA USA)
The overload protection button has to be reset frequently to build pressure. It will run for approximately 10 to 15 seconds and shutdown. I can reset and the unit will run again. The pressure will increase approximately 10 PSI each time I reset. The oil level is good. The motor does not feal or bind when rotated by hand.
This unit was given to me because of this problem. I do not know how this unit has been handled or maintained.
Can you give me any suggestions of things to check or parts you think could give me this problem?
Hi James. If by "overload protection button " you mean the thermal cut out that protects the motor, it is popping, presumably, because the motor is overheating.
By resetting so frequently, you are quite likely harming the motor.
You don't indicate in your post how your air compressor is powered? By that, I mean, are you using an extension cord or power bar into which you plug the compressor cord? If so, stop!
You need clean power to run an air compressor effectively, and that means if not a dedicated plug of, preferably, a 20 amp circuit, at least one that has no other applicances pulling power from the same circuit as the compressor is trying to run.
If the power supply is good, then I would next suspect the start / run capacitor is failing.
There is a page on this site explaining how to test a capacitor.
Model 40400 pressure switch leaks?
I have a model 40400, and the diaphram in the air pressure switch has a hole in it. Harbor Freight said it will take 3 months to get a replacement switch. How do I get this problem solved?
Dump the air in the tank, leave the compressor unplugged, remove the switch, and take it to the stores in the area that sell air compressors. You will find one that is similar, I am sure.
Many of the import compressors sold at a variety of big box stores use the same or similar make of pressure switch.
Or, ask the store where they send the compressors for warranty work, and go there.
Or, look at the pressure switch page on this site. Usually there are advertisers offering them.
Correct Pressure Switch Wiring
I have a central pneumatic Model 40400 Air Compressor,
It requires a new pressure switch.
The new switch has the following designations next to the terminals. N, P, G. Im assuming the designations mean Neutral, Power and Ground.
The old switch was wired as follows: black wire connected to the N terminal, white wire connected to the P terminal and green wire connected to ground.
Seems to me it should be as follows: white wire connected to N, black wire connected to P and green wire connected to G. Am I correct?
I have verified with a volt meter that the black wire (plugged into an oulet)is hot.
Hi there... if the question is are your thoughts about wiring the pressure switch correct, or was the old switch setup correct, not being an electrician I cannot tell you which is correct.
It were me wiring up the new switch, however, I'd go with your version... :-)