Another Compressor Question?

[Arturo Villegas]

Hello,

I am just getting into sandblasting and I am seeing I am going to need a bigger compressor (80 gallon) but all the good ones are runnig on 220V. I was thinking of running it of a generator to avoid running cable ( just an excuse to buy a generator) and dealing with electrical issues.

Do any of you folks run any machines of a generator all day/everyday or at least 2-3 hours a day?


Thanks,

[Gary Max]

Why not just run the compressor with a gas motor??????

[Roy Harding]

Hello,

I am just getting into sandblasting and I am seeing I am going to need a bigger compressor (80 gallon) but all the good ones are runnig on 220V. I was thinking of running it of a generator to avoid running cable ( just an excuse to buy a generator) and dealing with electrical issues.

Do any of you folks run any machines of a generator all day/everyday or at least 2-3 hours a day?


Thanks,

I have an 80 gal 220V 1Ph compressor. When it first arrived I didn't yet have power to the shop - so I hooked it up to my 5600 watt generator. It constantly tripped the 20 amp breaker on the genny (compressor said it only drew 15 amps) - if I kept switching the breaker back on until the compressor came up to speed, it worked great - but it constantly tripped that breaker on startup.

When I eventually got power to the shop and wired the compressor, it became clear that it needs a "delay" breaker - the initial startup of the compressor caused enough temporary draw of amperage that a "normal" breaker couldn't handle it.

Your mileage may vary.

I like the gasoline powered compressor idea for your situation.

[Arturo Villegas]

Uh, never taught of that( with gas prices right now). Its worth a taught. How reliable are gas operated compressors?

[Tom Veatch]

...5600 watt generator. It constantly tripped the 20 amp breaker on the genny (compressor said it only drew 15 amps)...When I eventually got power to the shop and wired the compressor, it became clear that it needs a "delay" breaker - the initial startup of the compressor caused enough temporary draw of amperage that a "normal" breaker couldn't handle it....

What was/is the surge rating on your generator. I assume the 5600 watts is a continuous output rating. Reason I ask is that the start surge of a 220v/15a compressor could easily approach or exceed an instantaneous 10 KVA peak. The breaker on your generator might be a "fast" breaker to protect the generator.

My experience has been that "normal" breakers sized greater than the FLA of the motor and operating within specs will handle the motor start surge. But, I infer from your post that you saw the same nuisance tripping with the motor connected to utility power through "normal" breakers. If that's the case, could it be that your compressor is exceptionally hard starting? Unloader valve malfuntion? How did you eventually solve the problem?

[Gary Max]

Contractors and service trucks use gas powered compressors all the time.

[Rob Russell]

Another option is to put the compressor where you have 240v power available and then run hoses to your work area.

[Pat Turner]

Forget it. Motors are the hardest to start loads. You would need a generator 2-3 times the rating of the compressor. thats why service trucks have a gas compressor even though they allready have a generator. Only exception is a few trucks with small wheelbarrow compressors, 2Hp or less.

Put the compressor in the house with PVC pipe to the shop (PVC isn't much of a hazard to human if underground), or upgrade the power, unless you want a 15kW generator (assuming 80 gallons means 5hp).

If you go PVC, transition to steel or copper, or sleave the PVC (even with more PVC) when above ground.

Only good thing about a compressor is the motor is totally unloaded when it first starts.