Irrigation well - control box relay overload

[msg2121]

I have a 4" well with a Franklin 3HP s425-17XMV pump and a Franklin model 2823028310 control box. The two overload relays on the bottom of the control box keep tripping when no water is being used, but if you open a valve or turn on a sprinkler zone and then reset the relays, it will pump fine until you stop the water use. It ran a 6 zone sequence for over an hour with no problem. Short delay between zones did not cause it to trip. Once the valves are closed for a minute or so the relays trip again. Not sure how old the system is but nothing has changed since I bought the house 3 years ago. Worked fine until I put it back into service this week. Pump and control box are covered in a flower bed, and the pressure tank and pressure switch are under the house.

Thanks for any advice you can provide.

 

[Valveman]

Those overloads will only trip while the pump is running. So it must still be running after you close the valves. You might have a leak or a bad check valve leaking back, which causes the pump to cycle. When the pump cycles on and off, those overloads will trip on the on part.

 

[Sponsor]

 

[msg2121]

I learned today that when I reset the relays on the control box, the start overload trips within a few seconds but the pump stays on. The main overload only trips after about 5 minutes of the pump running. During this time the pump runs constantly even though there are no water valves open and no signs of leaks in the system. It is not cycling, just running constant for about 5 minutes.

 

[Valveman]

If the pump is running the pressure should be climbing and the pressure switch should shut off the pump. If the pressure is not climbing, the pump is either not running or there is a break in the water line.

 

[Reach4]

I would suggest you get a pressure gauge that you can screw onto a hose spigot.

 

[msg2121]

I have a spigot pressure tester and the one at the tank that is very slow to react to change. I took the one off the tank and flushed out some crud that was keeping it from functioning properly. Both are reading within a few psi with the pump on and water flowing. I discovered I have a cycle stop valve on the pipe coming out of the well just before it goes into the ground to the pressure tank, so there's no cycling. At a moderate water draw the pressure holds about 42psi, wide open it pumps strong but the pressure creeps down and a low draw causes it to slowly creep up. When you close all valves it slowly creeps up to 60 where the pressure valve shuts it off. I looked up the function of the cycle stop valve and I guess that's why I'm not getting the 40/60 bounce I was expecting. Now to the real cause of the problem. The start overload trips within a few seconds of start up and the main overload keeps the pump operating. When water use stops, the system slowly rises to 60psi and the pressure switch shuts the pump off. The main overload does not trip at this point. The main overload only trips when you open a valve and it tries to start with the start overload already tripped. If I reset the start overload and then open a valve it works fine, but again the start overload trips as soon as the pump gets going so it won't restart the next time unless I reset the start overload.

Now, somebody please tell me the problem is the control box or a cheap part in the control box and not the pump.

Thanks,

 

[Valveman]

Sounds like the pump is running ok and the CSV is working. If it is not tripping the run overload during normal operation, it should not be drawing too much amperage. You can check that with a clip around amp meter. A 3HP is about 17 amps if I remember correctly. Those Klix-On type overloads can only be reset a few times before they get weak and won't hold. If the running amps are less than 17, I would just replace the overload. And I would never pull a pump until I tried a new box first.

 

[msg2121]

I replaced the start overload switch and it is still doing the same thing. Start overload is tripping after a few seconds and once it reaches pressure and shuts off, it won't restart unless I reset the start overload. Any other suggestions?

 

[Valveman]

You are going to need a clip around amp meter. We need to know if the motor is pulling more than 17 amps, or if there is just something wrong in the control box. A 3HP needs a CSV with a minimum flow of 3 GPM. If the CSV has a 1 GPM minimum, as for 2HP and smaller, it is possible the motor bearing or those Franklin "floating impellers" (dragging impellers) got hot and it is pulling more than 17 amps, which means the overload is doing what it is suppose to do.

 

[msg2121]

It is pulling about 18.85 amps. I found some Franklin specs that say a 3hp should be 17.8 +- 10%. 18.85 is within that spec but I am not positive I am looking at the correct Franklin table for my pump.

 

[Valveman]

OK then. Since the pump will run fine after started, even when the start overload trips out, it is probably not a pump/motor problem. But the start overload should not trip after the pump is up and running, as it should have been disconnected from the circuit by the start relay. So I am guessing the start relay is not opening up as it should. Maybe a bad spring, sticking contacts, or a weak coil. The motor will certainly pull enough amps to trip the overload if the start relay doesn't open up as it should. That is about the only thing you have not replaced.

 

[msg2121]

Just to close the loop, I replaced the entire pump control box and that solved the problem. I am not sure whether it is a bad capacitor or relay. I will test those at some point and replace the bad component so I have a spare if the new one goes bad. I understand those control boxes often develop problems after 5 years or so. Thanks for all of the advice.

 

[Valveman]

Thanks for "closing the loop" and letting use know. That is so much better than thinking no news is good news.