Air Compressor and Motor HP question

[BareBones]

I have a Gardner Denver single stage but 2 cylinder air compressor. That has a max output psi of 150 lbs. It has a 19" dual groove wheel on it. It came with a 1.5 HP Baldor motor that is wired to single phase 220v. It will turn and build pressure up to about 70 lbs and then the belt on the electric motor starts to slip but the electric motor keeps running. It only has a 3" single groove pulley on it.

Do I need a stronger HP motor? I'm dying to get this thing going but can't get it to build more than 70 lbs. Let me konw if you need any more info.

Thanks,
Bob

 

[A_Pmech]

Bob,

How tight is the belt? About 1/2" deflection per 16" of center distance is a rough approximation for a B section V-belt. There should be little to no slack side whipping.

I'd give Gardner Denver or one of their service centers a call and describe the pump with model#, serial#, etc. They should be able to tell you the power input required at various rated speeds. Then you can make an intelligent decision on how to size the motor.

 

[fatfillup]

Is that the origional motor? If so it should be sized correctly. If you have doubts about the motor call G D.

 

[BareBones]

OK I put a 3 HP motor that spins at 3450 RPM. It fills up quite quickly to 60 PSI but after that it struggles and takes around 5 minutes to build 10 more PSI.

I have a 1.5 inch motor pulley and 19" compressor pulley. I know I need a 4 inch motor pulley but can't find one with a double groove. Does anyone know where to find one?

Any other ideas to figure out how to build more pressure.

Bob

 

[Jared]

what rpm is the motor it came with? should probobly be 1725.

 

[Gary S]

If the belt is slipping but the motor continues to run without overheating, you don't have a motor problem. Since the larger motor doesn't pump efficiently either, you most likely have a problem in the pump or a leak that is bleeding off your air.

 

[nissan_crawler]

You replaced a motor because a belt is slipping

I would put the original motor back on and deal with the belt issue. Put a new belt on with proper tension, if that doesn't work, go to dual pulleys. If you can't find them, call eaton, that's where I got mine from. Are you even spinning the pump at the right RPM?

If it runs right up to 60 and flatlines, does it have head unloaders that are kicking in? Is it a 2 stage with a bad second stage?

 

[BareBones]

I replaced the motor becuase the original was long gone and when I got it, it had a 1.5 HP and that's not enough to turn the motor. I was able to get proper tension on the belt and now it's either a compressor or pulley problem. It's a single stage 2 cylinder.

Bob