I hope someone knows more about this than I do and can provide a good answer instead of just poking in the dark. I need to know if the motor is shot or what?

I'm not up to pulling and replacing this again by myself. My gin pole is somewhere else and I'm not in shape to go get it. Pump guy is on standby to replace with a new Grundfos for $2650.

Symptoms:

Stopped while sprinkling at about midnight two weeks ago. Tripped thermal OL
Reset, tripped again... gave up on watering because I've had pumps do this before. Maybe pumping air or bad capacitor
Had been watering for weeks without incident. Though well might be going dry. Driller says this is unlikely. Lowered pump 60' anyway.

Checked start and run capacitor... Start good, run bad, connections terrible, corroded something terrible and of course broke two when I pulled to check capacitor. Relay lug shot, a wonder it would start at all.

Built another box from two.. ran OK for about 30 min then went into the thermal OL mode again if I water. Gave up on watering. Will run house without tripping so run house

Order new control box. Wire it up. Pump starts and waters fine for about 45 min. Good high flow. Trips thermal OL again. Give up watering again. Revert to just house.

Goes fine on just house for a day or two and then trips thermal OL again. Reset and here I sit.

Is this motor shot? The readings suggest no but maybe so?

Detailed Info:

3 HP Pentair, 3 wire, BRAND NEW Control Box, pump just lowered 60', pump about 4 years old. Third pump since 1998. It is a Unitra Pump and a Pentair Motor. Bought from Becker's in Slaton, Texas in 2011 as a package of pump, motor and box. Box is Pentair.

#10 to control box 30' or so; Pentair says this can go 103'
#6 down well 240' or so; Pentair says this can go 253'

Well 342' deep, WL abt 120' last I checked, pump hung at 240'

Status of motor now but will check again soon and be really careful with a higher count Multi-meter:

Check pump windings. RGY to ground... Infinite OHMS. B-Y 1 OHM, R-Y 2-3 OHM.
Pentair says B-Y 1.0 to 1.4 OHM and R-Y 2.0 to 2.5 OHM

Check running amps. Y 14.4 amps, B 12.2 amps... did not check R while starting, I'm not that fast.
Pentair says 17.5 amps and locked rotor of 76.4... don't specify Y or B separate
Franklin says Y 17.0, B 14.5, R 4.5 for 3 hp motor

Cycle stop inactive for about a year... guts came apart

 

Welcome to the forums.

Pumps for 30 minutes and then cuts out on OL.

Do you have a pressure tank ?
Do you have a pressure switch ? If yes....what pressure settings.

 

#10 is good for more than 300'
#6 is good for more than 800'

Previous post read meters table!

 

80 gallon free air tank
Set for about 40 and 75... always have had it set for that. never changed it. Switch is less than a year old.

 

Was there a point to your question? Neither fact seem very important to the problem.

 

I can judge the condition of the pump by how fast it recovers pressure. If you didn't have a tank then there really is no recovery time. Many people using a well for irrigation don't use a pressure tank and some don't even use a pressure switch as the pump is activated by the irrigation controller.

 

OK, well it recovers very fast but it will not sustain pumping while watering. It cycles of course but more slowly without the cycle stop valve but it does cycle since it is putting out good rate. It just seems to get hot when trying to push a lot of water over a long period of time.

Thought someone might be able to render some judgement from the amperage and resistance readings.

 

Your resistance measurements are fine. They don't show any leakage to ground although you need to put the meter in a higher scale if analog. If digital.... ok.

The current they spec is the 240v to the pump circuit. Check the main supply before the control box for current draw . You don't appear to have a starting issue.

Have you checked with the place you purchased the pump from or Pentair about the duty cycle ?

Dane will be by tomorrow.... he may have other ideas.

 

Duty cycle is 100%. Huge design factor.

I'm going to check it all again tomorrow with a better multi-meter. The one I used before didn't have a high count rate.. digital automatic but a Volt-amp-ohm meter. Good tools just not high count.

I'm sure the voltage is OK, we have been using it for ever but I'll check it again.