Need help from the motor gurus

[Bill Dufour]

If you have to take the motor off do yourself a favor and cut the cord. Then add a male and female end to the two sections. This will make testing and removal much easier next time. You may want to cut it short on the motor. It will be easy to add a new short whip and male cord end onto the motor if you have take it to the workbench anyway.
Bill

[Matt Day]

Okay, I’m back after I erroneously got banned!

First thing, I finally realized the “H” shaped button existed!

So, I’ve got voltage at the line in, between the contactor and thermal overload, and terminal side. I also plugged in the motor directly to the wall and it ran it for 20 seconds or so, to make sure it was truly running properly. Check.

What next?

Because of the timing of delivery with Amazon, I went ahead and ordered a new starter. If the starter is dead, which I can only assume it is, I wanted the starter ASAP so I can get back to work.
https://www.amazon.com/gp/aw/d/B002LVUWHM

[Dan Friedrichs]

So when you press either the little black button or the H button, you get voltage at those brass bars between the contactor and the overload? But not on the output of the overload?

If so, then the overload is the problem.

Just to double-check, you tried pressing the red "reset" button on the overload and nothing happens?

If so, the overload is bad. The starter you bought on Amazon will be a good replacement for the entire starter.

Edit to add: is something broken on the overload? It looks like maybe the plastic case above the reset button is broken / loose / missing a tab?

[Matt Day]

A discovery!

I verified that I do have voltage through the switch to the motor leads. While testing and playing with the starter a bit, I realized that if I push the “H” button in hard and hold it, the motor spins up to full speed. I was just pushing it enough to engage the button to stay down, which gave me a split second of power. I thought that was it, but pushing it and holding it I suppose completes the circuit completely for the motor to fully turn on.

The small black button (non-“H”) doesn’t do this. I can push it quite firmly with no effect.

What I think is happening is the on button (small black button) isn’t engaging the “H” button (reset button?) fully. Is there anything to do about this? Blow it out some more? Possible corrosion?

[Dan Friedrichs]

Ah, a good discovery, indeed.

So your overload is fine, and the mechanical bits of your contactor are fine. When you press and hold the "H", you are manually closing the contacts that bring power to the motor.

The little black switch is supposed to temporarily energize the coil (the electromagnet) which pulls the contacts closed. If your starter were working properly, when you press the little black button, you'd see the "H" get "pulled" down by the coil (electromagnet). That's what's broken, here - either the coil, itself, or the little black button.

1) Disconnect power and use an ohmmeter to make sure the little black button is working as a momentary button should

2) If so, reconnect power and check that you're getting voltage to the coil when you press the button. I can't see the coil contacts in your picture of the starter - there should be two screws somewhere near the contactor side labeled something like "A"/"B" or "A1"/"A2", etc. If you can find both of them, measure the voltage between them when you press the little black button - should be 240V. If so, then your coil is bad (replace the contactor), if not, then you've got a problem with the wiring to the little black button.

As you dig into this, it gets a little confusing: the little black button momentarily energizes the coil, then a 4th switch pole on the main contactor "takes over" and supplies voltage to the coil once you release the button. This is why a motor starter will keep a motor off if the power blinks - an interruption in power causes the coil to release the main contactor, and since the 4th switch pole on the contactor was supplying voltage to the coil, once the contactor opens, it won't re-close until you press that momentary button. So those 4 screws to the left of the button are associated with that 4th contactor pole.

A4391D24-E148-40BA-8A3C-50AECA1FA6EB.jpg

[Malcolm McLeod]

Another way to describe this is that the little black button is part of the 'start' circuit to the coil, and the 4th switch pole is part of the 'holding' (or latch) circuit.

The O/L contact presumably is part of and feeds power to both, so it could also be the source of the problem...? (This is the #2 green bubble Dan has added.)

[Don Jarvie]

This is kind of after the fact since you ordered a new starter but if the motor itself has a reset switch you can dump the starter and use a switch for 20 amp. The starter is great but the overload protection is more important if the motor has no overload protection.

[Bill Dufour]

Do you have any remote stop or start buttons? it sounds like a bad stop switch somewhere.
Bill D

[Matt Day]

Dan - I have continuity across the start button.
The terminal you marked is blank. The one next to it goes up top left to L11, along with Line in.
None of the wires have changed and it’s been working for me for 5 years or more, and however many years before that for the previous owner.
When I press the small black start button the H button does pull close as it should, just not enough for some reason.


Bill - no remote buttons.

[Dan Friedrichs]

Hmmm...

So that sounds like a coil problem - it's not generating enough "pull" to fully engage the contacts. That's possible if the coil partially shorted itself, for instance - so while not a "common" fault, certainly a believable one that has some logical basis.

That black wire you mentioned...I had assumed it was to power the coil, as the coil power is usually ran through the overcurrent device at the location I drew the green line. I'm confused what that black wire does, then. In the Amazon link you posted, the last picture they show is a pretty good diagram of what yours should look like. In their picture, the coil is "A" and "B", and you can see how a wire comes down from the line input (in the upper left - just like yours), down to the overcurrent device ("98"), then from the overcurrent device to one side of the coil ("A").

Can you locate any similar-looking coil connections?

(Although at this point it's mostly academic - sounds like you'll be replacing the whole starter)

[Bill Dufour]

Not unkown for the armature to be rusted or gummed up with sawdust. If you can remove the armature from the coil clean it and the inside of the coil with compressed air and degreaser if it looks/feels gummy. If rusted it may need wire brush or sandpaper.
Are the contacts worn and need replacing re shaping?
Bill D.

[Malcolm McLeod]

Dan - I have continuity across the start button.
The terminal you marked is blank. ....

Matt, it's tough to be sure from a photo, but it looks like the #1 (red) note that Dan added to the pic points to terminals with no wire on them, BUT they do look to have a conductor 'strap' - running to the holding contact (L4). As per Dan, it may be academic, but just one more thing to be aware of...

Dan's advice seems thorough and more timely than mine, so I am going radio-silent to avoid confusion and will just follow along.

[Matt Day]

Just an update, but the new starter was essentially the exact same one I had, just brand new and working. Fit right up, wired, and works as it should.

I’m going to assume a bad coil with the old one. Wonder if it’s worth it to try and find a replacement coil/contactor? My feeble google searches haven’t found one, but I’m not exactly sure the part.

[John C Cox]

Probably not worth your time... The old one probably made it the better of 20 years.... Do you have a good reason to keep a weird spare laying around that long for another go around?