Keg Washer Air Compressor Suggestions

[Sean_KillsBoro]

We recently purchased an automatic keg washer that requires a 5HP 60-80 gal air compressor. The air compressor recommended by the keg washer manufacturer is this one listed below:

Ingersoll Rand Type-30 Reciprocating Air Compressor

We ran all the electric in our brew house according to the spec provided on the air compressor at the time, which was that it required 230V, 22.5 amps. However, we recently discovered that upon starting the compressor, it draws 60 amps. Our electric currently only provides 50amp to the location we'd like to hook it up. All the electric is ran, and the walls are closed up.

So in short, would anyone have an air compressor that provides comparable power to the Ingersoll Rand Type-30, that draws less than 50amp upon power up?

Thank you in advance.

[pargiris]

Did it trip the breaker?

How are you measuring amps load?

[rdcpro]

I'm assuming this is a three phase motor load? Is your circuit breaker tripping when the motor starts?

For a three phase motor, your branch circuit wiring should be rated for at least 125% of the FLC (Full Load Current) rating as listed in Table 430.250 [Three-Phase Motors] (430.22) of the NEC. Starting inrush current is usually 5-6 times the FLA of the motor, but you don't size the conductors based on that. So, if the circuit is based on a nameplate rating of 22.5 amps, (which means you probably ran #10 THHN, right?), you should have a 30A circuit there.

If you find yourself in the situation where your actual branch circuit rating is not big enough to handle the starting inrush current on the compressor, but it IS rated properly for the FLC, then your best choice is to implement a soft start on the air compressor. This might be a good idea anyway. There are soft start motor controllers, and some larger motors have a special winding that allows them to start more slowly, though probably not on a motor as small as yours. If the circuit breaker is tripping, you might want to replace it with one that does not have a low magnetic trip on it. Most circuit breakers will trip on a moderate overload over a long period of time (thermal trip). The lower the overload, the longer it takes to trip. Then they have a short circuit protection trip that's designed to trip very quickly on an extremely high current--much higher than 60 Amps. There are a few, however, that have magnetic trips that could be affected by the inrush current. Check with your electrician on this.

If you ran #10 THHN/THWN copper to the air compressor, it seems like that should be enough--you can verify with your building department. If you ran #12 wire, you've got a problem. Also, if the circuit shares a conduit with other loads, you might have to de-rate the conductors, which could cause you grief too, because you're already pretty close on the rating. 22.5A * 125% = 28.125A. If the circuit is rated at 30A, and you have to derate it, you might end up under 28A.

In any case, you don't size conductors for the starting inrush; that's built in to the tables.

Regards,
Mike Sharp

[TGTimm]

We use a 5 hp I-R rotary compressor to run our bottling line, keg washer/filler, and anything else we need air for. I keeps up with no problems, even when running the bottling line and keg washer at the same time. We do use small--30 gal--compressor tanks at the points of high use as buffer tanks to provide the big bursts of air the keg washer and bottler require.

The 5 hp only draws 15 amps.

The rotary is much quieter and requires less maintenance than a recip. Combined with a refrigerated air dryer and micro-filter, it provides very clean, dry air. I'd never consider a recip compressor again.