Help. Well Pump Trips Overload. Franklin FPS4000 240v single phase with Franklin Control box

[l00semarble]

Pump is 1.5hp Franklin single phase 3-wire. Control box diagram below.

Issue: When power sent to control box the pump pulls 41a (about 31a on red/run and 11a on yel/start) and pump does not run. After a little bit main overload breaker on control box trips.

Steps done:
- Pump windings measure correct on ohmmeter. Windings not shorted to ground and winding resistance is per Franklin specs.
- Both capacitors test in spec with Fluke multimeter capacitance test
- Relay coil (per test C) tests in spec
- Relay contacts (per test D) tests in spec (dead short)
- Voltage holds at at least 230v leg to leg and each at least 120v to ground even during 40a load so I don't think there is a voltage supply issue.
- Pump pulled and checked for locked rotor condition. Rotor can be turned by grabing shaft with channel locks. It is stiff but it does move. Not sure how stiff is normal. Pump stack can be rotated by hand.

I am most suspecting the relay but I don't understand it. I assume is normally closed and that internally pin 2 is other other end of the coil so it seems that the coil would always be energized and therefor the contacts open and start cap out of circuit. But maybe the thing has an internal delay or maybe it takes time for voltage to build on the start winding to energize pin 2? or???

I pulled off the wire from #2 on relay as I wanted to test if full voltage was coming through the contacts or actually if it was opening the contacts once energized. With #2 disconnected and the box energized the relay chatters which would be because it is normally closed so 1 energizes 2 which then fires coil which opens contact and deenergizes 2 which then closes contact and reenergize 2 and back and forth . This seems to confirm that pin 2 being energized does hold it open and does seem to kind of confirm the relay is trying to work if it is just a simple relay.

Is this relay just a simple mechanical relay (coil closes contacts) or is there somethign more complicated going on in there?

Also, for what its worth the pump has been abused. The installation is in Costa Rica and it was done "Tico" style. This is not a normal drilled well but a makeshift shallow well at the bottom of a ravine in the jungle with a stream. The pump has been subjected to silting and also is installed in a 3ft diameter well without a flow concentrator to force water to flow over pump body to cool it.

One other odd thing. As I am troubleshooting by myself it is difficult because the well/pump is a difficult 10 minute hike down into the jungle but the control box up at the top so I can't see the pump when actuating the power. When I had the pump motor disconnected from the pump body I left it laying there out of the water with the shaft free to spin in the air. I went back to control box and did more troubleshooting and found the same overload current. I only applied power to the box for a few seconds at a time to troubleshoot. Same exact symptoms with motor shaft connected to nothing. BUT....when I hiked back down to the pump which was at least 10 minutes I was surprised that the motor was HOT. Not just slightly warm but hot enough that I could only keep my hand on it for 4-5 seconds before it was uncomfortable. How the hell could it get that hot with me just energizing it for a few seconds at a time maybe 7-8 times?

Sorry for long....I'll end it here.

 

[Valveman]

Motors get so hot in the second it takes to start that they need to run for at least 60 seconds to dissipate that heat. Especially at locked rotor amps, as 40 amps is a lot of heat. The motor should spin freely. Check the stick up height of the motor shaft and if it is any lower than 1.5" it lets the pump impellers drag on top of being locked down itself. A lot of cycling on and off and some sile will do that to a motor. Pump is probably still good.

 

[Sponsor]

 

[trex85]

I'm pretty sure I'm having the same problem as you. Same motor control box and my main overload is popping after/during multiple run cycles (e.g. when my irrigation system is running). While the pump is only supporting my household usage, it has not tripped, but I can tell something is not happy in the circuit as the pump seems to be banging (for lack of a better way to describe it) while running. I have an 80 gallon pressure tank with 40/60 PSI pressure switch setting for context.

Inside my control box, there's some burned up dust underneath the relay and it had been buzzing during prior cycles, thus I expect it is the culprit. I've ordered a new relay as well as new start and run caps, which will arrive tomorrow and can report back when I install those. I'm hopeful that fixes the issue, otherwise I'll accelerate my longer term plan of getting a new variable speed pump installed. In the meantime, I've shut my irrigation off and am only using water for critical needs to limit stress on the pump.

 

[Reach4]

Reconsider the variable speed pump. https://terrylove.com/forums/index.php?search/6365776/&q="variable+speed"+pump&o=relevance

 

[Valveman]

I'm pretty sure I'm having the same problem as you. Same motor control box and my main overload is popping after/during multiple run cycles (e.g. when my irrigation system is running). While the pump is only supporting my household usage, it has not tripped, but I can tell something is not happy in the circuit as the pump seems to be banging (for lack of a better way to describe it) while running. I have an 80 gallon pressure tank with 40/60 PSI pressure switch setting for context.

Inside my control box, there's some burned up dust underneath the relay and it had been buzzing during prior cycles, thus I expect it is the culprit. I've ordered a new relay as well as new start and run caps, which will arrive tomorrow and can report back when I install those. I'm hopeful that fixes the issue, otherwise I'll accelerate my longer term plan of getting a new variable speed pump installed. In the meantime, I've shut my irrigation off and am only using water for critical needs to limit stress on the pump.

OMG dude! Don't jump from the frying pan into the fire by switching to a variable speed pump. If the pump was cycling, (banging on and off) while the irrigation was running, I can guarantee you have a problem. Hopefully the start cap and relay will get you back to running but the cycling has already damaged the motor. Simply adding a Cycle Stop Valve solves all these problems, switching to a VFD causes a bunch more problems.

 

[trex85]

As an update, I replaced the relay and both caps and the well is not tripping the overload anymore. It is also running smoothly again. I expect the original poster is having the same issue and recommend a new relay to resolve the issue. The start cap measured a bit low at 100 uFD, but the run cap was spot on - still replaced them anyways because I had the new parts and do not have a good idea as to how old this box is as it was installed before I bought the property.

I appreciate the feedback on using a Cycle Stop Valve. I'm going to look into retrofitting one into the current setup. For my curiosity, can you comment on if the back pressure adds stress to the pump? When my irrigation is running, the pump spends about 2 hours going on and off every handful of minutes. With a Cycle Stop, I expect it would spend the 2 hours running almost all the time?

 

[Valveman]

For my curiosity, can you comment on if the back pressure adds stress to the pump?

OMG! NO! That is a 30 year old lie perpetuated by pump companies who don't want your pump lasting longer than the average of 7 years they planned it to last. For the forty eleventh time, BACK PRESSURE IS GOOD FOR PUMPS! Back pressure makes the motor amps drop and the motor runs cooler. Back pressure keeps the pump from putting out too much water and cycling itself to death.

Cycling on and off every handful of minutes is the worst thing you can do to a pump. Running continuously for as long as water is being used like a Cycle Stop Valve would do, is the best thing you can do for a pump. Pumps are made to run continuously 24/7/365. I have one feeding a stock tank that hasn't shut off since 1996. It is the cycling on and off that destroys pumps.

Having already needed to replace a start cap, relay, or pressure switch means cycling has already done major damage to your pump/motor. Getting a Cycle Stop Valve can stop the bleeding as soon as it is installed, but can't do anything about the blood already lost.