induction motor troubleshooting

[Tyler Davis]

I'm working on a Grizzly dust collector, G1029, 2 HP. Bought it used from the same guy I bought a jointer from (which works fine). No reason for me to think there is anything wrong with it (pulled out of a commercial shop a few months ago.)

I've got it wired into my subpanel with a 20-amp double-pole breaker (actually two single-poles with the poles tied together with a screw). Turn on the breaker,hit the start button --> nothing. Not even trying to wind up. Not popping the breaker like a starved motor would. With multimeter, measured 120V from red to ground, and 120V from black to ground. Should give me 240V, right? The starting capacitor "looks" fine (don't know what a bad one looks like but I have heard they fail spectacularly :eek:)

so what gives?

[Lance Norris]

Your 120v taps need to be out of phase from each other. Thats why a 220v breaker takes a tap from the left and the right bars in the breaker box. If I understood your description correctly.

[Mike Henderson]

If you can't measure 240 volts from red to black you don't have 240 volts. As Lance said, 240 volts has to be taken off the two bars in the circuit box - you can't take two 120 volt circuits from the same side of the box. You probably have zero volts from red to black.

Get a proper breaker and it should work for you.

Mike

[Jerry White]

Lance is right. Measure from red to black. You should read approximatelly 240 volts AC.

Edit: Whoops....I need to write faster. Mike said it better.

[Tyler Davis]

ah...that could explain it. So what is the difference between a breaker with the poles tied together and a single-height breaker with the poles ties together? My bus bars alternate so any two adjacent connections would be black/red/black/red out of phase, right?

[Mike Henderson]

ah...that could explain it. So what is the difference between a breaker with the poles tied together and a single-height breaker with the poles ties together? My bus bars alternate so any two adjacent connections would be black/red/black/red out of phase, right?
Check the voltage between the hot wires on two adjacent breakers. It'll be either 240 volts or zero volts. That will answer your question.

Mike

[Tyler Davis]

makes sense. thanks guys:cool:

[John Terefenko]

Who said the dust collector is 240. Nowhere in your statement do I see that you say it is 240. But if the collector is indeed 240 single phase (not 3 phase as would be found in an industrial shop) then you need to make sure you have 240 as the others have stated. I highly suggest you get yourself a 2 pole 20 amp breaker and get it as soon as you can. Get rid of the screw. Is there a starter on this unit?? In the starter there is a set of contacts and these may have tripped with the moving so make sure they are reset. By the way the bus alternates top to bottom so you want two spaces on top of one another and not side by side. One other thing, there maybe a thermal switch on the side of the motor that tripped. If so just reset.

[Ken Fitzgerald]

ah...that could explain it. So what is the difference between a breaker with the poles tied together and a single-height breaker with the poles ties together? My bus bars alternate so any two adjacent connections would be black/red/black/red out of phase, right?

In a service panel that has 220 in it, there will be two buss bars running parallel to each other. Each bar carries 120VAC that is out of phase with the 120 VAC on the other buss bar.

A 120 breaker will have a post that makes contact with one of those two buss bars. Putting 2 120VAC breakers next to each other and tying their handles together won't give you 240 unless.....they each are tied to a different buss bar.

A 220 breaker will have 2 posts..one post will make contact with one buss bar...the other post will make contact with the other buss bar.

You should measure 240 VAC from red to black at the input.

Becareful.....120 and 240 VAC can kill!

[Bruce Wrenn]

In my sixty plus years, I have never seen single phase a panel that the the slots didn't alternate from one leg of the 220 to the other. As for the screw, was it furnished by the original maker of these breakers? If not, then it is most likely illegal. Many companies make a tie bar to connect two separate breakers to make a double pole breaker. Square D, QC breakers have a hole in the handle for a tie bar, but non of the supply houses in my area carry the tie device. The problem sounds more like a on / off switch problem to me. Use this circuit to power another machine. If the other machine works, then the circuit is good.

[Ron McAllister]

If the capacitor is not obviously bloated or "popped" you can remove the capacitor and check it with an analog multimeter. Make sure it is discharged then read across the terminals, the meter will briefly deflect. Discharge it again, reverse the leads of your meter on the capacitor and see if it deflects again. If it does, its good, if there is no deflection at all, replace it. Make sure it is disconnected off the motor before you do this.