laser throwing hp pump breaker

[kempape]

i have changed it twice in last 2 weeks... mtr pulls about 70 amps,,, ive checked it at least 20 times in last 2 weeks and amps are always below 75(slight differential in gatlin and arch amp draw),,,, pump seems fine(not using oil/pressure good/),,, contactor(siemens) seems fine. i went from 80 to 90 amp breaker and that no help. it seems to throw the breaker in the morning?!,,,(then wiill be fine all day{possibly})...~any help appreciated,,, tia kemp c..................the baldor motor is 25 hp... the pump is a general,,,unit bout 9 yrs old,,,,````this is drivin me nuts!

 

[raisetheprice]

Any leaks? The fact that it's happening in the morning says to me that the belts & pulleys may be getting soaked as they sit idle all nite?

 

[kempape]

it seems to be dry...if i goofed up the sequence of the wires to he new breaker could that be the problem?......

 

[I.B. Washincars]

Switching a 3 phase wire will cause the motor to run the other direction. I have no idea if a pump puts more load on it if it is running the wrong way.

 

[Mike]

Your lex air valves could be sticking, causing the pump to run only on the unloader, this would cause a spike in amperage. (probally over 100 amps)

Check your lex air valves, and mac valve to ensure they are working properly.
Check air supply for water. There is a water trap on the incoming air line to the pump station but it may not be working properly.

Have a local electrican check what size your circut breaker should be. Typical is 125% of load. So if your motor name plate says 70 amps you should have a 90 amp breaker. (local codes may effect this)

If you are tripping a 90 amp breaker, again see the first comments.

 

[ken-pro]

Check the wiring inside the motor junction box - vibration on the stand could cause the wire to rub through the insulation and short against the box.

Also stuck Lexair Valve, plugged nozzles on undercarriage / Gatlin Guns, faulty high pressure regulator could all cause an intermittent over amperage condition.

 

[RykoPro]

Are all three legs reading the same amps? What is the initial in rush current and how long does it take to level out? Does the pump have an over load? If the over load is not tripping than the problem is most likely between the over load and the breaker or in the service panel itself.

 

[whitescout]

What is your overload set at? Try turning the overload down, and see if the overload trips. It sounds to me, that if the breaker is tripping, (the 80 and 90), that you are getting a short, versus an overamp situation.

I would agree that checking for leaks would be a good idea, as well as checking the motor junction box on the side of the motor. I would suspect that you are getting some water inside this box, and that is why it is tripping in the A.M., or that you have a wire(s) rubbing just wrong enough at times to create a short.

 

[kempape]

thnx everyone,,,,, we got our lex air valve kit last nite,,,, and the old one was a bit "sticky",,,,ordered new tips(arch and gatlin),,,,the amps bump up for a second or two then ramp down,,,, checked and adjusted unloader valve,,,havent ckecked wires at junction box ,but wil ck that tomorrow,,, ```again, thnx everyone,,,i really appreciate the help,,,kemp