New Submersible Pump not working

[jjvande]

Hello,

This is my first post on the forum and I want to first start by saying that reading the information on this forum has been a valuable education to get me to where I'm at today... now I may have met my limit of understanding on this particular pump repair.

My wife and I just installed a new replacement well pump/motor (franlkin electric 1.5hp), control box (2823008110), drop line (60 ft of poly with flow valve just above pump), and 4-conductor electrical cable to fix the 28 year (!!!) old pump assembly that came with our new house. That old pump was working great for 2 years until it just stopped pumping. Removal of the old pump revealed major damage inside the pump.

This system consists of a 60ft deep well with drop pipe connecting directly into a sprinkler manifold where there are 6 valves controlled by a sprinkler controller. Normal operation is that the controller triggers a main relay at the 240V supply to the Franklin control box. At the same time the sprinkler valve is opened for a given zone for a given amount of time until this is repeated for the next zone. There is a 5 minute rest between zones.

The problem we're having is that with all the new equipment installed (did this myself) the main overload in the control box is tripping within 15 seconds.
Measurements:
Line voltage supplied to control box: 243 VAC
Voltage at pump connections (ground level): 238 VAC
Main winding resistance: 2.4 Ohms at control box (spec is 1.7-2.1)
Start winding resistance: 9.0 Ohms at control box(spec is 7.5-9.2)
When initiated, the current is high in both windings (start is about 6A, run is 35A) and the start relay doesn't appear to be operating (removed cover and can visibly see that the relay is not triggering during operation) The start winding current is not initially high and does not fall within a second, consistent with the start relay not operating. The start winding checks out as okay per the instructions written inside the cover of the control box.
The 35A in the run winding continues until the overload trips within 15 seconds. This is way above spec. Is there anything other than a bad motor that could cause this? The run capacitor measures 15uF with my DMM.
I've verified that there are no shorts in the wiring out to the motor (100ft from the control box and 60ft down).
The motor winding resistances are in spec.
I even pulled the motor back up to give it a spin and it turns very easily by hand.
I operated the motor for about 10 seconds in a barrel of water and get the same measurements (water did flow out of the pitless elbow at what looked like a pretty good rate)
I double checked the orientation of the flow valve installed just above the motor.
A second control box was installed (wasn't sure if the initial control box was faulty) and the problem persists.

At this point I'm out of ideas and to me all signs are pointing to a bad motor/pump assembly, even though it was all new from an online vendor. It also measures good, turns free, and otherwise looked perfect when I pulled it up the second time.

Any ideas? I really hate to try and start a warranty process without any real data to show this pump/motor is bad.

Thanks

 

[Valveman]

Did you get the wires crossed at the splice?

 

[Sponsor]

 

[jjvande]

Did you get the wires crossed at the splice?

Tonight I disconnected the pump electrical connections at the top of the well hole casing. I then put a 9 Volt battery across the black/red leads going back to the control box. Back at the control box end I confirmed the polarity of the battery and measured 9 Volts at the black/red leads. This indicates the black/red at the control box are the same polarity as the black/red at the connection to the wire going down to the pump. I wasn't sure if there was a junction somewhere between the control box and the top of the well where colors could be mixed up - effectively wiring the pump windings to the incorrect location on the control box.
I also went back and checked pictures I took of the splice connections at the pump. Red-red, black-black, green-green, yellow-yellow... all is good there. This seems to agree with the fact that I am getting what appear to be resistance readings within spec for each of the windings and that they correspond to the correct wire color at the control box.

Is it conceivable that my DMM measurements of the motor resistance is giving me false sense that the motor is good?
Since I was able to spin the motor-pump shaft coupling easily by hand, could it be that the pump has had some kind of internal failure leading to an overload of the motor?
My understanding of the start relay is that its triggering is somewhat dependent on the main winding (motor) coming up to speed under the correct load. If the motor never reaches top speed and the correct load is it possible that the start relay wouldn't trigger?

I'm hoping the problems (high main amps and lack of start relay trigger) are related to a single cause. One thing I haven't been able to verify is the 126uF start capacitor, the DMM doesn't seem to want to measure this high of value (reading is pinned at 0.00000 for about 10 seconds then reads "oL").

Thanks

 

[Reach4]

I'm hoping the problems (high main amps and lack of start relay trigger) are related to a single cause. One thing I haven't been able to verify is the 126uF start capacitor, the DMM doesn't seem to want to measure this high of value (reading is pinned at 0.00000 for about 10 seconds then reads "oL").

If you put two capacitors in series, the net capacitance is 1/ ( (1/c1)+(1/c2) ) . That capacitance is in range of your capacitance meter. For example, 25 uF in series with 125 uF would be 20.83 uF.

I don't see how a bad start cap would explain your symptom.

 

[Valveman]

Then most likely there is something wrong in the control box. Maybe the start relay, capacitor, or both.

 

[jjvande]

Just to follow up on this thread... Problem Fixed!

Turns out it was a bad area of the main winding wire lead out in the conduit going over my house in between the control box and the top of the well terminations. A section of wire was shorting to ground (the conduit itself) under high loads, but not when measuring via DMM. This short prevented the relay from triggering and the control box was confused.

Thanks for all your help. I found this short by getting new wire and jumping the old wire at every junction possible, one-by-one, starting at the well head. After working my way over the house it started working once I bypassed the bad section of wire.