electric motors

Not sure where this belongs so I'll try it here. I putting together an air compressor for my kid and the motor seems to be smarter than I am. I got a new pressure switch today because it was missing and wired it by the directions and when I turn it on all it does is buzz and sound like it trying to turn both ways at once. all looks fine inside and it turns smooth. the centrifugal mechanism and contacts seems fine but I'm not sure what it does I suspect one or both of the capacitors. Any thoughts would be appreciated. trying to do this on the cheap so I don't want to buy a motor.

How big is it? It's not three-phase is it? That sounds exactly what a 3phase motor does when connected to standard 220 or whatever.

HotRodZilla said:

How big is it? It's not three-phase is it? That sounds exactly what a 3phase motor does when connected to standard 220 or whatever.

Click to expand...

Not three phase. It's the same one I have in my shop and wired the same way.

If it is wired right and the same as the one in your shop, why not just swap starting capacitors and see if it works. AC or 'universal' motors are a bit of a mystery to me and I just end out out doing what the voices tell me to. I guess you could check the resistance on the windings and compare them to specs or to the motor that is working.

Start Relay required/bad? Some motors don't start on AC current.

A lot of multimeters have a capacitance setting (microfarad). Spec is on the capacitor.

Capacitors are cheap. Change it.

Or make sure the power is on, and test it with your tongue.

I suggest you contact Ionbeam. He does not follow this forum but you may find him on the other forum.

Old Michael said:

A lot of multimeters have a capacitance setting (microfarad). Spec is on the capacitor.Capacitors are cheap. Change it.

Or make sure the power is on, and test it with your tongue.

Click to expand...

And for dogs sake get pictures!!!

Bustanut joker said:

Old Michael said:

A lot of multimeters have a capacitance setting (microfarad). Spec is on the capacitor.Capacitors are cheap. Change it.

Or make sure the power is on, and test it with your tongue.

Click to expand...

And for dogs sake get pictures!!!

Click to expand...

Up yours sheep breath

Old Michael said:

Or make sure the power is on, and test it with your tongue.

Click to expand...

assuming this comprises the bulk of your technical acumen, it explains a LOT

Sometimes the motor can be wired for either 220V or 110V. There should be a wiring diagram on the inside of the junction box cover and just double check that the wiring is correct. You have to pull the end cover off the motor to check this next item. The centrifugal switch contacts may be defective. The contacts on the switch are closed when the motor is stopped and open when the motor starts getting up to speed. You can also check that the centrifugal mechanism is operating freely.

Electrolytic capacitors do dry out over time. At the plant we routinely changed out electrolytic capacitors on a 10 year cycle. If it is an older motor that may be the problem since the capacitor is there to create a phase shift in the starting coils that in turn creates the torque to rotate the motor from rest.

Call George, Escapefjrtist

Echoing 'fitter, I was going to suggest make sure it's wired for the proper voltage. AuburnFJR is our resident electrical expert, give him a shout.

--G

The tag says 230 volts only and my shop compressor is the same. I got it to spin up once but now it does nothing. After the holiday cluster f@#k at my house I'll take it off the unit and do a complete inspection.

https://electrical-systems-lighting.knoji.com/how-to-test-start-and-run-capacitors/ Start and run capacitors for single phase AC motors can be checked with an analog ohm meter

Pressure release valve? A lot of older motors even with capacitors don't have the ooomph anymore to start against a load. As others have mentioned:

Capacitors are cheap, buy new ones. Remove the load and see what happens. Check & clean the centrifugal switch. Also, you say you got it to start once but now, does the shaft spin freely by hand? Any lube fittings? Sometimes a drop or six of light oil in the fitting loosens things up.

FJRay said:

The tag says 230 volts only and my shop compressor is the same. I got it to spin up once but now it does nothing. After the holiday cluster f@#k at my house I'll take it off the unit and do a complete inspection.

Click to expand...

You dip shit, somebody seen you coming.

You probably have one of those goofy assed Canadian motors. They only run on canadian electricity.

Bustanut joker said:

FJRay said:

The tag says 230 volts only and my shop compressor is the same. I got it to spin up once but now it does nothing. After the holiday cluster f@#k at my house I'll take it off the unit and do a complete inspection.

Click to expand...

You dip shit, somebody seen you coming.

You probably have one of those goofy assed Canadian motors. They only run on canadian electricity.

Click to expand...

Better to be seen coming than sneaking up the backside like you and the sheep.

Motor says made in the good old USA . Not that the canucks aren't a bit goofy.

Hey!