Self Serve Pump Stand tripping Motor Starter

[Rudy]

I've got a 25+ year old wash with original pump stands (Cat 623 and Dayton 5Hp 3ph motors).

One of my bays is occasionally (randomly) tripping the motor starter.

I've never had this happen. Motor? Bad overload? Loose connection which causes the amps to increase?

Where to start? Any experiences?

 

[Eric H]

Time to get out your trusty clamp on amp meter!
Test the FLA (full load amps) on each leg of the 3 phase power. IIRC, my motors pull about 14 amps yours may be more or less. Check to make sure the overload relay is adjusted properly. https://www.kleen-ritecorp.com/p-26525-allen-bradley-overlay-relay-54-27amps.aspx On the overload relay there is an adjustment to increase or decease the tipping point of the relay. On the Allen Bradley relay in the link the adjustment is just to the right of the blue reset button.
There may be another issue but that is where I would start.

 

[2Biz]

Good advice from Eric. I would only add to "First" make sure the over-load on the problem bay is set the same as the other bays, then go from there....

 

[Eric H]

I would only add to "First"

Sure, take the easy way...

 

[Rudy]

We found a wire completely loose coming out of the bottom of the contactor. Reinserted the wire...tightened it up. Done.

 

[Jeff_L]

I know you fixed it, but from an overload perspective, your motor spec plate should tell you the amp draw for each leg. That is what you should reference when checking each one. I only point this out because it is possible that the motor on this bay may different than the other bays, so the overload may be set to a different value.

 

[Rudy]

My overloads are not adjustable. They are Square D fixed value "heaters"....with a value of about 15amps.

My attendant today told me the amp draw on the nameplate of the motor was 10 amps.

It sounds like 15 amp heaters are perhaps to large a value???

Nevertheless....they've been working fine for 25+ years....so if it ain't broke...I doesn't need to be fixed.

 

[2Biz]

Sure, take the easy way...

I always try start with the easiest and most obvious first! But usually ends up much deeper than that!

 

[MEP001]

My overloads are not adjustable. They are Square D fixed value "heaters"....with a value of about 15amps.

My attendant today told me the amp draw on the nameplate of the motor was 10 amps.

It sounds like 15 amp heaters are perhaps to large a value???

Nevertheless....they've been working fine for 25+ years....so if it ain't broke...I doesn't need to be fixed.

I've seen many pump stands with that same contactor. IIRC the options were either 10 or 15 amp with 10 being slightly underrated and would trip on hot days.