Air compressor advice

[Lost Californian]

wellhell. Went to the barn to do some tractor work, and the lift won't lift. Heh, no air. Mebbe the pressure switch got stuck with the current weather changes, it has before. Nothing so easy.

I have power to the motor, but the motor won't run. spin it by hand, and there is a not nice yucky sounding grinding. Here are pichers of the confounded thing...

Since the tank is 68 years old, I am guessing the rest of it is, also. Is it time to replace the entire setup, or just see about finding a new 2hp electric motor that would fit this thing?

I ain't knowledgeable about these things.

 

[Hardscrable]

Your call but if it was me I would soon own a new compressor.

 

[Butch627]

If it was mine I would disconnect belt and run power direct into motor with nothing in between and see what happens. If motor does not run I would find an old school elect motor repair place and let them look at it. If that does not work then I would buy a new motor with same rpm and amp ratings. Is it 120 or 220?
I would look at Surplus Center and Northern Tool both online for new motor.

 

[GodFearinGunTotin]

If it was mine I would disconnect belt and run power direct into motor with nothing in between and see what happens. If motor does not run I would find an old school elect motor repair place and let them look at it. If that does not work then I would buy a new motor with same rpm and amp ratings. Is it 120 or 220?
I would look at Surplus Center and Northern Tool both online for new motor.

Yeah, need to determine if the motor is making the noise of if it’s the pump. Could be the pump has seized up and the overloads on the motor has kicked out. If the motor has thermal overloads, there should be a reset button on it somewhere that will reset them when pressed.

As Butch says removing the belt and checking the pump and the motor separately will tell you what’s gone bad. Personally, I bet it’s the pump.

 

[Lost Californian]

With the circuit breaker turned off, and leaving the belt in place, I can grab the compressor wheel and spin it by hand. Both the compressor and the motor turn. I hear the cylinders pumping air, sucking in and pushing out to tank. The motor spins but there is a grinding noise. I can get my voltmeter right to the wires going to the motor, and I find proper voltage there. Unless I start stripping old wires, or disassembling the motor, I cannot check any closer.

Harbor Freight has a motor, right size, 2hp, and right rpm, 1800, for 179.99.

A direct replacement unit is out of my price range - 175psi, 2 stage, 80 gal, 220v unit. They are starting just under $2000. My main use is for the in ground hydraulic lift, and miscellaneous air tools I have collected, because I have(had?) a compressor.

 

[Lost Californian]

Since I thought the motor had failed, I removed it. Then I thought I should follow the advice I asked for, so I pulled an extension cord over to the motor, shoved one wire in this hole, the other wire in that hole, and spinnnnnn went the motor. Pulled them out, reversed the wires, and spinnnnn went the motor, in the other direction.

Color me confounded.

The circuit breaker is a ganged 30A pair. 1 cable with 3 wires go to the switch box on the compressor. See the photo below.



The black and the red are attached to the ganged breakers, one on each. White goes to ground in the breaker box.

On the out side, both black wires go to the pressure switch, each attached to the "line" connectors. The switch does make contact between the line contacts and the motor contacts.

Motor still makes a funny, not good, grinding sound when I spin it by hand, but I can't hear it when it is running.

 

[rem788]

What you might hear when spinning the motor by hand are the start up contacts in the motor. They rub against a device on the motor shaft and disengage when the motor rpm's reach a certain point by centrifugal force. If the motor runs without a load but stalls under load the start up contacts may not be working or you might have a defective start up capacitor. I can't see in your pictures if there is one, it is usually a round tube like device mounted on the top of the motor. These are usually cheap to replace to see if it corrects the problem. Good luck.

 

[bobzilla]

Not related but my 60 gallon sanborn compressor started making noise a year ago when running. Sounded like bad bearings in the pump. Belt started slipping when it was cold and infogured it was just seizing up. Then I noticed something odd sticking out of the belt guard and realized the belt was coming apart and the sound was the delaminating belt hitting the guard. New belt and it’s quiet as ever.

Sometimes it’s just the simple things.

 

[04FXSTS]

When you spin the motor does it turn smoothly or is there some "roughness" you can feel? If so it is probably the bearings going out and bearings are cheap. The problem with bearing replacement is the fit in the end bells can be worn. If that is the case a competent motor repair shop can fix everything. A competent machine shop could also fix the fits, bore out, sleeve and re-bore to correct size. The fits also must be done so they are in line, no big deal to do but very important. I worked in a motor repair shop a couple years back in the 1990's so have done this a lot. Jim.

 

[Lost Californian]

This is the motor....





Could be as said by rem788, because there is no roughness, more like a dragging sound. Spins real nice when I put the 120v to it, no noise, no vibrations.

Located a shop here locally that rebuilds or repairs or whatever electric motors. Talked with them yesterday, and will be dropping it off there next week.

40 years ago the Navy taught me all about electricity and electronics. The motors and generators course kicked my tail. Last time I had to deal with this stuff was over 30 years ago. Sucks getting old. Memories fade and die.

 

[Jaybird1980]

This is the motor....
View attachment 245086
View attachment 245087
View attachment 245088
View attachment 245089

Could be as said by rem788, because there is no roughness, more like a dragging sound. Spins real nice when I put the 120v to it, no noise, no vibrations.

Located a shop here locally that rebuilds or repairs or whatever electric motors. Talked with them yesterday, and will be dropping it off there next week.

40 years ago the Navy taught me all about electricity and electronics. The motors and generators course kicked my tail. Last time I had to deal with this stuff was over 30 years ago. Sucks getting old. Memories fade and die.

The noise can be as Rem788 explained. It could also be a sloppy bearing that will get quieter under mag center. Do you have much movement of shaft? Either way the motor shop should get it squared away.

Being that old I would be curious how rusty the tank is. Do you drain it regularly?

 

[Lost Californian]

Took it in to Wabash Valley Motor and Machine this morning. They spent 5 minutes with it and said it is a basket case. Windings are burnt up, and parts of the internals are missing, and are no longer made.

A new motor from them is ~$541. 18 month no questions asked warranty. I am unwilling to spend that, and take a gamble that the compressor is still good, or will last how long with a new motor. The two old technicians working on it said the motor was made prior to 1953, based on its physical makeup (ask them, I don't recall what all they said). The tank is stamped 1954. It is probably about rusted out.

Going to get a whole new setup sometime in the future. Just cain't afford one right now.

Thanks for all the suggestions and help.