Motor starter keeps tripping

[slash007]

The motor starter on one of my bays keeps occasionally tripping. A reset will get it working for some time, but it's happening more often now. What should I be looking for as the cause? Best way to test?

 

[OurTown]

Check all connections to make sure they are tight.

 

[Randy]

The motor starter on one of my bays keeps occasionally tripping. A reset will get it working for some time, but it's happening more often now. What should I be looking for as the cause? Best way to test?

Put a clamp on Amp meter on the motor leads when it's starting and running to see how many Amps the motor is drawing.

 

[slash007]

Put a clamp on Amp meter on the motor leads when it's starting and running to see how many Amps the motor is drawing.

Will try that. Thanks.

 

[Rfreeman]

I bet it's what Randy says....happen to me as well a few years back....ended up being a bad motor.

 

[Mchas]

If it’s a single phase motor, chances are it’s going bad. Mine seem to last maybe 3-5 years max.

 

[slash007]

If it’s a single phase motor, chances are it’s going bad. Mine seem to last maybe 3-5 years max.

It's a 3 phase motor

 

[Dan kamsickas]

Could just be the overload is starting to go bad. We all have to come to grips with stuff not lasting like it used to. The days of getting decades out of things are done.

 

[dallas]

Get you a motor tester from grainger. Very handy and useful over time. Also make sure to check connections at contactor and overload. Overtime some wires work themselves loose.

 

[slash007]

So far I have tightened all wires at the overload and contactor. None really seemed to be loose. My next step was to swap the overload, then test the motor properly to make sure it was the issue. It's so intermittent, makes it harder to diagnose.

 

[Keno]

A megger will quickly tell you the health of your motor - pricey though. Maybe a motor shop will test it for you for a couple $

 

[dallas]

Swap the contactor/overload with another bay and see if the problem follows the contactor or motor. That should also tell you the problem if you don’t have another way to test.

 

[Greg Pack]

I use this once in a blue moon and it's been useful at times. However, moisture inside a motor will call it to fail. The motor can dry out and start working again. Moisture is not usually an issue on a pump stand but more of an issue with a motor on an IBA.

Supco Megohmmeter, 500VDC M500 | Zoro

Order Supco Megohmmeter, 500VDC, M500 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.

www.zoro.com

 

[slash007]

I use this once in a blue moon and it's been useful at times. However, moisture inside a motor will call it to fail. The motor can dry out and start working again. Moisture is not usually an issue on a pump stand but more of an issue with a motor on an IBA.

Supco Megohmmeter, 500VDC M500 | Zoro

Order Supco Megohmmeter, 500VDC, M500 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.

www.zoro.com

How do you use that to test the motor exactly?

 

[2Biz]

Get yourself a cheap clamp meter from Harbor Freight or Amazon, $20-$30....Use it to test the amps on each of the 3 hot leads feeding the contactor/overload when the motor is running. They should all be the same amps or very close. If one feed reads higher amps than the other two, the motor is bad. If they are all the same, the contactor might be going bad. Or you can also check amp load against what the overload is set at. All my overloads have an adjustable amp setting...If the overload is set too close to the amp load of the motor, then it will trip. The overload needs to be set a few amps higher than actual load.

 

[Greg Pack]

How do you use that to test the motor exactly?

The Supco M500 is a one trick pony and I rarely use it, but it’s nice to verify a bad motor when replacing for a customer. It uses a simple system of red/yellow/green lights to show condition of the windings. With a standard meter, running amps should be essentially the same on each leg. Lots of YouTube videos showing how to diagnose with a meter. This one gives a quick overview.

it.


I found a video one time that was kind of a quick intro to 3 phase and it was good. I’ll try to find it.

 

[rshiggaon]

Here is a good Youtube video for testing 3 phase motor:

 

[slash007]

So I noticed a little water leak on that motor that we are discussing. It was the little Cat Unloader that Coleman uses, so I removed it and just capped it off. I went to the bay to test and the pressure seemed to be extra strong. My arm really pulled back when I squeezed the trigger. I went inside and the pressure gauge was passed the 2k mark! No idea how that happened, but I lowered it back to 1150 and the pressure held. I'm positive the high pressure was the culprit. So 2 questions... Is there any need for the Cat unloader that was on there, and what could cause the pressure to spike like that? I assume the Paraplate regulator somehow acted up, but it has never happened before.

 

[2Biz]

So I noticed a little water leak on that motor that we are discussing. It was the little Cat Unloader that Coleman uses, so I removed it and just capped it off. I went to the bay to test and the pressure seemed to be extra strong. My arm really pulled back when I squeezed the trigger. I went inside and the pressure gauge was passed the 2k mark! No idea how that happened, but I lowered it back to 1150 and the pressure held. I'm positive the high pressure was the culprit. So 2 questions... Is there any need for the Cat unloader that was on there, and what could cause the pressure to spike like that? I assume the Paraplate regulator somehow acted up, but it has never happened before.

So the overload did its job! We all missed the obvious, checking pump pressure first! Using a clamp meter on the 3 phase feeds would have clued you in too! I think I'd be taking those regulators apart to see what is going on inside them....They usually don't start spiking pressure unless something is wrong...

 

[slash007]

Crazy that it ended up being just the overload doing it's job lol. I'll rebuild the regulator just in case. Nice when you find the culprit.