shop compressor

[Jim Will]

Hi all
I have a small Campbell Hausfeld compressor that comes up to 100lbs pres. then as you use the air when it gets low enough the motor tries to start again and blows the breaker. The compressor is plugged direct to outlet. What could it be?
Jim Will

 

[Anonymous-0]

I'm certainly no expert, but does it have the factory size/length cord on it?

Is the wiring and breaker of the electricity source adequate?

If the compressor has an unloader, which allows it to start at no load, is it working properly?

Do you have the proper size pulleys for the motor?

Are you exceeding the machine's duty cycle?

Is there any reason to believe the motor is working harder than it was intended to?

The answer to one or more of the above questions must be "yes".


Glenn F.

 

[2t2@IA]

Is there other load on that breaker such as an electric heater, etc?

 

[Anonymous-0]

Your wiring isnt isnt on a circut that provides enough starting current for the motor to start under load. When tank pressure is zero there isnt the same load as when the pressure in the tank calls for the motor to restart. You just need larger wire and a larger breaker.Like the other posts have said. You didnt say what size breaker you have on the circut and what other things are on the same circut.Check the motor to see what the AMPs required to operate.

 

[Dandy Don]

I'd say that you need a 30 amp breaker and a deciated line (nothin' else on it) and no more than three or four feet of lead in wire. NO
EXTENSION cords. Good luck.
Don

 

[Pajamafied John]

Jim, I have the exact same problem with a Husky compressor and have had the problem since new. I switched to a dedicated 20amp line with 12ga wire and it still trips out about half the time it starts to recharge the tank. The motor can be wired for 110 or 220. Im thinking of going to 220 if I can figure how to do it.

 

[RayP(MI)]

Going to 220v will cut current consumption in half, as well as making starting far easier. I had a similar problem, changed to 220, and never looked back. Was like a new compressor. Check the inside of the access cover on the motor for wireing diagrams, they are most likely there. You may need to change out pressure switch for a dual contact model. No big problem, available at most hardware stores of any repute. Will also need new power cord, and 220v outlet with sufficient current carrying capacity.

 

[rustyfarmall]

I think the unloading valve is defective. This is the valve that bleeds the pressure off of the compressor when it shuts off. If the unloading valve is not working, you still have pressure on the compressor piston, and the electric motor cannot overcome this, so you trip a breaker.

 

[ChrisB]

Blindly suggesting a 30amp breaker for what could be a 1hp motor with 11 amp draw and a 14gauge cable?????

Please refrain from doing any wiring in my house, and I pray your insurance is paid up.

 

[evielboweviel]

I agree
Ron

 

[Sean McDonnell]

Sounds like it's probably the unloader valve mentioned in earlier posts. They do go bad from time to time. Be careful if you do decide to "upgrade" the electrical feed. Look at the nameplate on the motor and see what current it draws first. There should be a space marked "FLA"
that's full load amps, that is what the motor should draw when working at it's full rated HP. Generally you are safe to size your feed for about 20% above that FLA number. example..a motor with a FLA marking of 20amps would work out to 24amps when you add the 20% so you would go with a 25 amp breaker and 10gauge wire. you are allowed to go to the next standard breaker size above what is required since there aren't any 24 amp breakers. Hope this helps.

 

[sbin]

That problem could also be caused buy the motor starting capacitor.

 

[johnand cindy]

install a dedicated 20AMP circuit. Inrush current too great check existing circuit with an amprobe. A 20 AMP is designed for 20A inrush current and operate at 16 AMPS 80% of total load.Also make sure wire size is correct #12. Also the receptical is 20A rated DO NOT buy junk outlets big brand names Hubbel,P&S,Woodhead, indrustrial grades are best. Do some research before making changes if unsure call a electrician. Been doing this for 33 years. John

 

[guido]

HEY Ray
You said that the compressor on 240v will draw less current? Can you explain.
Guido.

 

[ChrisB]

(quoted from post at 14:30:44 01/15/08) HEY Ray
You said that the compressor on 240v will draw less current? Can you explain.
Guido.

While I am not Ray.....

and in the simplest way to explain.

current = amps

Double the voltage and the current (amps) will be half. Thus if a motor running at 120v and drawing 20 amps is converted to 230v then the amp draw will be 10amps.

Common thinking it is best to run a motor at a highest voltage allowed. Add to this the recent insane prices of copper cable. cheaper too as the cable rating (gauge) is determined by amp draw and not voltage.

Not that running 220v save on your electric bill as some think:

Watts = Voltage x Amps

Which will be the same either way, 120 or 220.

 

[JerryCPP(WA)]

My small compressor has a pressure relief valve (unloader)as part of the switch. Look on the underside of the switch - you might see a tab about 1/4 inch by 3/4 inch. When the pressure switch shuts off, that tab should move and you should hear a rush of air, unloading the air line. If you don't hear this, pull up on that tab with your finger. If that releases a bit of air, that unloader is sticking. Clean it up or replace it. Other wise, you have some excellent posts regarding power supply.

 

[dave guest]

Well I guess we know its bad wiring(too small) or a bad compressor. But, we have to know the size of compressor. Most newer ones give you a recommended circuit rating(amps). National code allows for a larger amperage circuit breaker when starting current of compressor is too much for conditions. Try compressor somewhere else, like kitchen circuit, which should be 20amp. Don't want to rewire everything if unit is bad. If unit is good, call electrician. Fairly common problem is man knows compresors.

 

[Anonymous-0]

I second sbin's reply. I replaced mine once already on my CH compressor. chris

 

[Janicholson]

The compressor on 220 will draw about 60% of the amps (at start up) as it did before. The 220 volts will cause that to still be more watts of power. Watts are amps times volts. This increase in total power is what makes it able to start. It will use more starting power (watts) but run approximately equal in energy consumption. JimN