Very odd amp draw at 1.5 hp submersible pump

[Ballvalve]

300 foot well, small use filling cistern. Power in to pumpsaver, 2009 Franklin unit, big box and a 1.5 hp Franklin deluxe control box. CSCR and mechanical relay and reset button. 2007

Off for the winter. Went to start up and pump kicked in and ran 5 seconds, reset blew. Started again and drew 9.8 amps for 5 seconds, pump ran and water moved. overload tripped [NOT at the pumpsaver but at the control box] Reset again and at start drew 44 amps. blew overload. Reset, started normally 9.8 amps, and then jumped fast to 44 amps. repeat about the same. Ran one time for 30 seconds at 9.8 amps and then up to 44 and trip. Never saw this before. Start cap okay. no leak to ground in 3 drop wires.

Dayton pump very low hours, clean water. What do you Sherlocks have to say about this? Cannot really test running values on the 3 drop wires as operating time is too short before going to 44 amps.

 

[Valveman]

Check the ohms. If it ohms out and there is no short, the motor is probably gunked up. When you open up a motor like that it is usually full of black gunk. The carbon from the thrust bearing wears off and makes thick chocolate milk out of the water in the motor. Carbon only wears off the thrust bearing when there is too much cycling and/or the motor is getting hot. A cooling shroud will solve the heating problem and a CSV will solve the cycling problem.

 

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[Ballvalve]

Thanks. Going to redo all resistance tests. So a motor can start at normal 10 amps and then churn up the crud to make it pull 44 amps?
Pump has been in water since 2007 with just 4 hours perhaps a year, clean water [800 foot deep well set at 300]

 

[Ballvalve]

Check the ohms. If it ohms out and there is no short, the motor is probably gunked up. When you open up a motor like that it is usually full of black gunk. The carbon from the thrust bearing wears off and makes thick chocolate milk out of the water in the motor. Carbon only wears off the thrust bearing when there is too much cycling and/or the motor is getting hot. A cooling shroud will solve the heating problem and a CSV will solve the cycling problem.

I did all the AIM manual tests and the pump and wires were all good. Got tired of dicking around and put in a new control box. BY that time I decided that the mechanical relay was the culprit, but didn't want to screw around in that old mud dauber filled box. Damned if it didn't start right up at 9.2 amps and finish at 9.5 when the tank was filled.

 

[Valveman]

Glad you got it working. Normally a control box problem would trip when the pump tries to start. it is unusual for a control box problem to allow the pump to run at the correct amps for any length of time before tripping the overload.

 

[Reach4]

Nice. Thanks for posting the resolution.

Regarding the insects, if you have big holes for wires, consider filling those with "duct seal".

 

[Ballvalve]

Glad you got it working. Normally a control box problem would trip when the pump tries to start. it is unusual for a control box problem to allow the pump to run at the correct amps for any length of time before tripping the overload.

Indeed, never saw such a thing before in any circuit. But the only thing left was the relay, cap's are all good. I am going to autopsy that relay and see if some weird internal fault. Pump ran through a few cycles with an amp draw a bit lower than historic as I have written on the box.

 

[Ballvalve]

Nice. Thanks for posting the resolution.

Regarding the insects, if you have big holes for wires, consider filling those with "duct seal".

Those insects are really tenacious. They fill up the ends of air hoses and small valves in the system and pressure of 90 psi wont blow them out. Like they make their own epoxy. Have the duct seal, just need more time in life.

 

[Ballvalve]

Glad you got it working. Normally a control box problem would trip when the pump tries to start. it is unusual for a control box problem to allow the pump to run at the correct amps for any length of time before tripping the overload.

Coil in the relay tested faulty, points were quite pitted, Looks like it would pull in after the motor started and then release back to start position in a few seconds. That's all I can figure from this odd failure.

 

[Valveman]

That is very possible as I have seen it before. But again, very unusual. Usually a bad relay just won't pull in or buzzes and trips the overload when the contacts don't make good connection.