Motor Starter has me stumped

[Country carwash]

Hello forum, I have a self serve bay with 5hp 3ph motor, motor is a marathon about 2 years old that stopped working, I replaced the Allen Bradley starter and thermal relay and the motor starts and runs for about 30 seconds and trips the relay, I have adjusted the relay up and it does not keep from tripping. I have replaced the starter and relay with brand new parts twice. thinking that it could be bad out of the box. I am getting 24v signal and brush etc is working just not motor for high pressure. I have also checked all the connections and replaced the ground wires to the motor and starter. New timer and rotary selector. Was working and stopped found out today that it had been running for about an hour prior to this issue starting while cleaning an automatic bay next to the self serve with a longer hose. Could the extended run time have caused an issue with the motor to draw to much power tripping the thermal relay? I hate to throw more money at it for a new motor just as a last resort. I am not sure that I can get brushes for the Marathon motor, online parts seem to be mixed if they are replaceable.

 

[Keno]

How many amps is the motor drawing while running? 3 phase motors don't use brushes

 

[Country carwash]

Well that certainly explains the lack of brushes, lol Sorry I am not as knowledgeable on some areas... How would you suggest I measure the amps while running?

 

[Fatboy769]

Looking at the overload, it sure looks like the wrong one. If I’m seeing it correctly, it goes from 0.1 to 0.5 amps?

 

[Keno]

Well that certainly explains the lack of brushes, lol Sorry I am not as knowledgeable on some areas... How would you suggest I measure the amps while running?

Amp clamp would be the easiest. Multimeter with an amp clamp is a super useful tool if you learn to use it correctly.

Looking at the overload, it sure looks like the wrong one. If I’m seeing it correctly, it goes from 0.1 to 0.5 amps?

That would explain it, if overload amps are so low.

 

[Country carwash]

the photo is actually one that is working properly and identical to the one that is not working correctly, please keep it coming, I have had three techs come look at this and has stumped them all

 

[Fatboy769]

At 230V that 5hp motor is pulling around 13.2 amps. Overload that I have always used, had an amp range of 12-18 amps.

 

[Fatboy769]

Do you have a picture of the plumbing of the high pressure pump? What pressure are you running the pump at?

 

[Country carwash]

the photo is actually one that is working properly and identical to the one that is not working correctly, please keep it coming, I have had three techs come look at this and has stumped them all

I stand corrected thank you!! likely our issue and several techs missed it, I double checked the panel and you are correct the ones that are working are 5.4-27 and the ones that they installed are .1-.5

 

[Randy]

I stand corrected thank you!! likely our issue and several techs missed it, I double checked the panel and you are correct the ones that are working are 5.4-27 and the ones that they installed are .1-.5

Are you saying the service tech's installed the .1 - .5 overload? You need to get a clamp on amp meter, every car wash operator should have one. You don't need a real expensive one, something like this will work AstroAI Digital Clamp meter multi meter. You can get one on Amazon for about $20.

 

[Greg Pack]

Are you saying the service tech's installed the .1 - .5 overload? You need to get a clamp on amp meter, every car wash operator should have one. You don't need a real expensive one, something like this will work AstroAI Digital Clamp meter multi meter. You can get one on Amazon for about $20.

Randy have you tried that one?

 

[Randy]

Randy have you tried that one?

Yes I've got a couple of them. Someone decided they needed my expensive Fluke tester so I bought a couple of these.