Air Compressor Issue

[paris_tj]

I got a used husky 60 gallon unit that acting strange. It kicks on to fill the tank and does so fine. The issue is the rpms change allot, is this normal? I would think the rpms by ear would stay pretty consistent.

Any ideas or suggestions are appreciated.

 

[Steevo]

The electric motor is supposed to operate at a set RPM, that is inherent in the design of the motor, and unchangeable.
If it is varying in speed, is it the motor, or the load on the motor that is causing it? Does your compressor pump have a bad valve that sticks and allows "freewheeling" at times?
In other words, is it periodically running faster that normal, or slower than normal?

 

[paris_tj]

Not that I know of. I just put a new crankshaft, rod, and pistons in it. The valves in it are nothing more than a two flat peices of metal.

All looked perfect. I got the unit cheap due to it having a broken crank.

 

[chrommagman]

Sounds like the motor is going out. It could be a short thought

 

[paris_tj]

I was thinking motor too, any way to check or know for sure? Other than buying a new one to find out!

 

[mad57]

Is it wired correctly? with the right guage wire?

 

[Mmfh]

Belt is tight?

 

[paris_tj]

Belt is tight but needs replacing, trying to find one local has been a challenge so far.

AS far wiring, I assume. We used the pigtail that came with it, 3 wires, 2 hot, 1 neutral. In to a 10/2 30 amp circuit. Same circuit I use my Hobart welder on with no issues.

 

[chrommagman]

You may want to take the belt off and tun it on. It should run much faster then w/ the belt on. if it starts to act funny then the motor needs replacement.

But you may want to take a look at the connections at the pressure switch and the motor.

 

[weaponizer]

I had just put a new belt on my IR and it started doing the same thing, but only when it reached the upper limits of pressure in the tank, i retightened the belt and it went away...

 

[larry_g]

Do you have an amp meter that you can monitor the situation with? If you have a widely varying amp draw then you have a varying load. If the amps are steady and the noise is changing then you may have some other mechanical anomaly. If you just rebuilt the pump head then that is the most likely problem area. Did you replace all the bearings and check the rod for straightness? Did you check the rod/crank bearing forproper clearance? What caused the crank to break in the first place? I made my living repairing equipment and learned long ago that the last thing 'fixed' is likely to be the cause of the next problem.

lg
no neat sig line

 

[Steevo]

2 hot and one neutral?
That doesn't sound right.
For 120v operation, it should have a hot, a neutral and a ground
For 230v operation, it should have two hots and a ground.

If it is wired as shown on the motor wiring diagram, we'll assume it is right.

With the belt removed, and the motor running, does it change speed or just run at a constant speed?

Can you put another load on it, like make it spin another motor (that is not plugged in) and see if it changes speeds with a constant load like that?

 

[paris_tj]

I will give these ideas a try tomorrow if I get a chance. 2 hot and ground... not a electrician. Crank broke at the flywheel due to bad casting. It now has new crank, rods, bearings, seals. Basically everything new. I made a quick video of it, maybe you can hear what I am talking about.

<iframe width="420" height="315" src="http://www.youtube.com/embed/UjO2sOs1dQU" frameborder="0" allowfullscreen></iframe>

 

[chrommagman]

sounds like there is a bearing that is about to lock up

 

[kams1973]

You may want to check the end play on your new crank.

 

[Zeke]

I'd say belt. It starts to slip, gets hot and gets some traction. Then it cools and the cycle starts all over.

 

[GreyOwl]

You did remember to put oil in the crankcase? Did that once in my trucks rearend when I rebuilt it.

 

[paris_tj]

Yeah It has oil, I checked that several times to make sure. I put a new belt on it, and I think it may have fixed it. I have not run it enough yet to know for sure yet.