Pump Over Current/Thermal Protection Shutoff in 10 Seconds

blakemc

Member
Jul 16, 2023
5
Florida
I have an approximate 14k gallon Gunite pool filtered by a Hayward SP3210X152BH Pump driven by a Century 1081 Dual Speed Motor SP3210Z2ME. The pool was installed 3 years ago and everything was working great until Friday morning on July 14th. The pump was found not running, but normally runs in low speed 16 hours a day. The motor is started at high speed of 3 minutes to prime and get pump to speed before switching to low speed.

The problem now is when the motor is started on high speed it only gets about 10 seconds in until it shuts off. I have done all the normal troubleshooting, but the facts are I can hear the thermal protection contact click on the back of the motor and the motor is hot and emits some burning smell. I hooked a clamp on ammeter to the high speed wire and measured a current between 21 and 19.5 amps which it normally runs < 10 amps. I got more of a surprise when I switched it over to the low speed wire and measured 24 amps which it normally runs < 2 amps. I did have to cheat the controller 3 min timer to get the low speed reading by only letting it run high for a few seconds before going to low so that could affect it, but I believe it was up to speed.

For troubleshooting I started by removing both run and start capacitors and testing them with an LC meter. All check out within tolerance and there is no visible bulging or leaking of fluid. I took the motor off the pump housing and removed the diffuser and verified there is nothing clogging the impeller. I cleaned the centrifugal switch on the back of the motor and even took a video of it breaking contact when at speed with my camera to verify it is working right. I also cleaned the main filter for good measure even though the pressure has not changed from its typical 10 psi.

I am not sure what to do at this point. I am afraid the only possibility left might be that the enamel insulation on some of the windings may have melted together resulting in my motor being less of an induction motor and more of a heater at this point.
 
Welcome to TFP.

Sounds to me like the motor needs to be rebuilt or replaced.
 
I have an approximate 14k gallon Gunite pool filtered by a Hayward SP3210X152BH Pump driven by a Century 1081 Dual Speed Motor SP3210Z2ME. The pool was installed 3 years ago and everything was working great until Friday morning on July 14th. The pump was found not running, but normally runs in low speed 16 hours a day. The motor is started at high speed of 3 minutes to prime and get pump to speed before switching to low speed.

The problem now is when the motor is started on high speed it only gets about 10 seconds in until it shuts off. I have done all the normal troubleshooting, but the facts are I can hear the thermal protection contact click on the back of the motor and the motor is hot and emits some burning smell. I hooked a clamp on ammeter to the high speed wire and measured a current between 21 and 19.5 amps which it normally runs < 10 amps. I got more of a surprise when I switched it over to the low speed wire and measured 24 amps which it normally runs < 2 amps. I did have to cheat the controller 3 min timer to get the low speed reading by only letting it run high for a few seconds before going to low so that could affect it, but I believe it was up to speed.

For troubleshooting I started by removing both run and start capacitors and testing them with an LC meter. All check out within tolerance and there is no visible bulging or leaking of fluid. I took the motor off the pump housing and removed the diffuser and verified there is nothing clogging the impeller. I cleaned the centrifugal switch on the back of the motor and even took a video of it breaking contact when at speed with my camera to verify it is working right. I also cleaned the main filter for good measure even though the pressure has not changed from its typical 10 psi.

I am not sure what to do at this point. I am afraid the only possibility left might be that the enamel insulation on some of the windings may have melted together resulting in my motor being less of an induction motor and more of a heater at this point.
Basically, it is new motor time. If the insulating coating had come off, it would be a dead short and trip the breaker. Two-speed motors were never particularly good though some last decades.
 
I hooked a clamp on ammeter to the high speed wire and measured a current between 21 and 19.5 amps which it normally runs < 10 amps. I got more of a surprise when I switched it over to the low speed wire and measured 24 amps which it normally runs < 2 amps.
Check the wiring because you might be powering both speeds at the same time due to a wiring problem.

Can you show all wiring?

hayward-spx321072mer-l.jpeg
 
Check the wiring because you might be powering both speeds at the same time due to a wiring problem.

Can you show all wiring?

hayward-spx321072mer-l.jpeg
Energizing both high and low circuits is a virtual dead short, some motors burn out almost instantly, some just trip a breaker. Have come in behind many repairs where the first guy didn't know how to work the system properly, or a homeowner though they could do it themselves. Really hated telling someone they had to get another new motor.

Happened when California Title 20 went into effect and every guy with a pool pole was trying to make a quick buck without a clue as to what they were doing. Sometimes they just walked off the job, called and left the carnage for me. Other times it was just a matter of knowing how to use a two-speed timer, that most people had never even heard of.
 
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I attached some pictures of the motor controller. I had wondered the same thing about it possibly energizing both coils at once, but as you can see in one of the pictures, I disconnected the low speed winding, attached to AUX1, and still measured the high speed winding at about 19 amps. I am going to try to upload the short video clip I took of the centrifugal switch to share audio of what it sounds like while running. It creates more noise than normal like a vibrating buzzing hum.

The other pictures of the pool show the sump I borrowed for now to get some circulation and the chlorine tabs at the outlet. I will brush and skim daily until I get a filter replacement.

At this point it is probably not looking good for the motor or my wallet, but I wanted to know if I was missing something. How do you tell when the motor is the culprit and not just throwing money at the problem hoping to fix it? I do greatly appreciate all advice since this is my fix experience owning a pool.
 

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Energizing both windings at the same time creates a jumbled mix of magnetic fields that tries to turn the rotor at two different speeds at the same time resulting in no actual rotation.

I don’t think that it creates a dead short.

I think that the problem “might” be due to powering both speeds at the same time.

Otherwise, I don’t know why it would use so much amperage.

A dead short would be an instantaneous trip at the breaker from the magnetic trip.

A dead short to ground would trip the GFCI and magnetic trip.

You can check the windings for resistance and check for continuity from the power terminals to ground.
 
I can't really follow your wiring.

Here is the way to wire a two speed in the manual.

You have to configure the pump as a two speed pump in the configuration menu and you have to designate the Aux relay as pump low speed.

Go through everything and verify.



1689545831309.png
 

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Go into the pump wiring compartment and disconnect the wire from the low speed terminal so that only the Common terminal and the Pump High Speed Terminal can get power at the same time.

Verify the voltage is correct.
 
Can you show the motor winding compartment?

Do you get continuity from the power terminals to ground?
I guess was actually measuring L1 and L2 from the other cabinet. I attached photos of the motor. I isolated all the wires as shown in the second picture. It is looking like rain was coming so I stopped for the moment but I think I need to take the L1 to Red measurements maybe. I think I may have missed some. Here is what I did record.

BLU TO PNK 1.8
BLU TO PUR 1.0
BLU TO RED 16.4
PNK TO PUR 1.0
PNK TO RED 15.5
PUR TO RED 16.0
L1 TO A 6.5
L2 TO A 6.0
L1 TO L2 1.8

INFINITE TO CHASSIS GND ON L1 L2 A BLU PUR PNK RED.
 

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Go into the pump wiring compartment and disconnect the wire from the low speed terminal so that only the Common terminal and the Pump High Speed Terminal can get power at the same time.

Verify the voltage is correct.
I did this test earlier in the first set of pics I posted. If you zoom in you can see the RED wire on the AUX1 Load Out Pin is disconnected and floating. No change in results.
 

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Disconnect the wire from A (Low Speed) to make sure that it cannot get power and then power L1 (High-Speed) and L2 (Common) with 240 volts to see what happens.

Then disconnect L1 (High-Speed) and power L2 (Common) and A (Low speed) with 240 volts to see what happens.

1689551892204.png
 
I did this test earlier in the first set of pics I posted. If you zoom in you can see the RED wire on the AUX1 Load Out Pin is disconnected and floating. No change in results.
I can't follow your wiring here and I am not sure that you are getting this correct.

Do it like I suggest to make sure that you are powering the high speed only and the low speed only.
 

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