I agree I think you got a defective motor you showed relieving the unloader valve so I assume when you had 40 psi in the tank your check valve isn’t allowing any pressure to flow back in other words you did check to make sure your check valve is not leaking back and causing motor to not be able to start up due to it lt maybe leaking pressure It seems like it’s leaking and no motor will be able to start back up if that check valve leaks anyway did you get it replaced and did it fix the problem ? If not seriously take out the check valve test it by blowing only one way
Took the motor apart and the centrifugal switch was stuck in the run position. Took it out and cleaned up the moving bits and it's run just fine ever since. Btw, I did test the check valve. Thought that was included in the video.
Last time I had this happen, it was the check valve in the receiver tank where the big line from the compressor head goes in. If that check valve doesn't seal off perfectly, the unloader valve may be too small, to keep the head pressure off the compressor, which makes it difficult for the motor to start. The compressor shouldn't even "know" how much pressure there is in the tank. I can tell, by the compressor rolling over abruptly when a piston reached top dead center, which tells me, that the motor is producing pretty good torque. Check the pill in the check valve,(remove the big line from the compressor to the tank, then, remove the check valve assembly) Then, make sure the starting capacitor is indeed being switched in when the motor is stopped.
In that case there would be continuous hissing from the unloader valve. Or if you manual release it, you can do it over and over again. Pretty easy to check.
@@davidrule1335on my compressor the reed valves are before the unloader valve, and the tank’s valve is after both. So you would hear the hissing, the reed valves would do absolutely nothing
I have a Ingersoll Rand 1 phase 220 the black is on one side and the white wires on the other side I have a red wire to solve two sides I know supposed to hook up where in the world do I hook the white wire if I take it loose
I had same problem with my air compressor, it had a 5” pulley on motor and after it cycled off and and like 3 times it would get really hot and humm. Had to attach an electric fan next to the pump just to help cool it down to finish my project. Later I swapped the 5” pulley to a 1 1/2” pulley and now it’s a lot more quiet but runs super slow. It won’t overheat no more but when I’m using power tools and it cycles back on it takes a good minute to shut off. I put a 4” pulley a new eBay 5hp motor and it works great the first 3-4 cycles and it also overheated, in the middle of using a da palm sander. Finally I swapped the 4” pulley to a 3” pulley and now it works perfect. Keep in mind also had to change v-belts too. Replaced the pressure switch when I first bought it so I know that was not the problem.
So basically my new 5hp eBay motor did the exact same thing as my old 3hp factory motor, I have a 60 gal compressor and most use a 4” motor drive pulley, so a 3” is pretty close enough, can handle the 5hp twin cylinder pump from harbor freight and it has 56” v-belt.
i have an old sears horizonal air compressor with a 250 lb shutoff switch. i got it for free took it home plugged it in and nothing. tried flipping the lever on the side of the pressure switch still nothing. it is still sitting in my garage gathering dust. it sounds like a winter project if I can get parts.
Start capacitor should disengage within a couple of seconds of starting. For some reason your start caps are still on, hence over current, motor heating, capacitor damage. Check unloader valve. If unloader valve is faulty, motor will never reach cut off rpm for centrifugal switch to kick off. Decrease in rpm is easy to detect. If unloader valve is working, it might be faulty centrifugal switch or starting capacitor. If only centrifugal switch is not working, rpm would seem normal. It is easy to test capacitors or you can swap a new one.
I have a Kobalt 30 gallon and the motor slows down to almost a stop then speeds back up again. I know this was years ago but maybe someone has a suggestion. Thanks
Thanks for the vid Jim.I purchased a new 3hp 60 gallon sanborn air compressor that after the first startup for the break in period when the compressor built up air & kicked out like its suppose to.When i hooked up the impact gun & started using air,the motor just hmmms & wont start up.Keep in mind its a new compressor.I replaced the start & run capacitor.I had a licensed electrician verify the wiring is correct.The compressor motor spins freely.Leading me to believe the electric motor is a dud.Your thoughts would be appreciated.
Lots of variables these days because of the cheap Chinesium products being shipped to the USA. I would bet the capacitors are weak...most of them are imported junk and only last maybe 1 to 2 years on equipment. You can put a meter on those caps and determine if they are weak. Replace them with USA made caps. Good electric motors are Leeson, Baldor and another brand I can't think of however, they are a good $400 to $600 for an application like this compressor.
A pressure switch isn’t technically the unloader. Start capacitor is pooched and your in tank CV or the unloader isn’t really working. Unloading should happen automatically on powering off the motor. I guess that’s why industrial electricians are different than we electro-mechanics rotating equipment specialists (Millwrights). Too high of an oil level causing oil carryover upon unloading caused the two valves (unloader and in tank check valve) to get sticky and a few starts under those conditions failed the start capacitor. Compressor troubleshooting is a Millwright’s job.
Pretty sure the motor lacks starting torque. It might be that the starter capacitor lost it's capacity, or it's a bad factory design that they didn't use a higher capacitance value cap. Still, you can improve the motor starting torque by changing it's original starting cap with a much much higher capacitance. Still the capacitor will not give it a really big starting torque and the motor may not start.
my compressor motor builds 40 pounds and motor slows down spining plz tell me what can be the problem i have bought if fresh outiside my state what cpuld be the problem
@@airframedent Why didn't you mention that in the video? We heard a click, was it the breaker or the start switch? We also heard the check valve leaking air back into the head.
Bad capacitor.. that guys got a start and a run.. likey both are out of spec.. hell i bought a brand new hermetic fridge compressor straight from the factory not too long ago and damn thing had a bad cap fresh off the floor. Made not even a few weeks prior with all the inspection and test marks on it... was rated +\- 10% and thing was out of spec 70%.. and friggn embraco tried to give me the run around and video myself testing the damn thing before they shipped me a new one.. million dollar company worried about a 60$ part.. jeez,.
I suggest you mind your own wallet and leave me to mind mine.... thank you very much. I fixed that motor a day or so after this video. It now has thousands of hrs on it and is running just fine.
