Breaker tripping when freeze termostat trips

[JeffSNC]

Here there, question for the pool experts. Recently when its been cold (in NC) my pump breaker has been tripper.

I've narrowed it down to when the freeze protection in my mechanical intermatic timer goes off, the breaker trips...so the question is, do you think I can just replace the thermostat vs the whole time?

Timer unit = Intermatic PF1102T - https://www.amazon.com/Intermatic-P...stat&qid=1549812445&s=gateway&sr=8-1-fkmrnull

Think problem will be solved if I just replace this thermostat? https://www.amazon.com/INTERMATIC-1...rmostat&qid=1549812445&s=gateway&sr=8-2-fkmr1

I'm assuming its be an easy swap (turning off the master power of course).

Thanks!

 

[mas985]

Is it the pump breaker that is tripping or GFCI?

The timer and thermostat appear to be working properly as it tries to turn on so I would suspect the breaker or pump has the issue more than the timer.

Does it trip when the scheduled time comes on?

 

[JeffSNC]

The breaker is tripping; and it does not trip when the timer comes on; only the freeze protection.

 

[mas985]

At the time the breaker trips, can you reset the breaker and see if the pump turns on or does the breaker immediately trip again?

 

[JeffSNC]

Tried that, trips only when the freeze protection kicks on...if i reset the breaker after it tripped, it will stay on. Also, the timer works fine (off and on without tripping the breaker); only when its from the thermostat.

 

[mas985]

What is the make/model/age of the pump?

Does the pump motor make a loud noise when running?

 

[JeffSNC]

Sounds perfect, 1 yr old Hayward Ecostar.

 

[mas985]

The Ecostar has it's own timer and low temp settings so why are you using an external timer at all?

See page 21:
https://hayward-pool-assets.com/ass...anuals/ecostar-owners-manual.pdf?fromCDN=true

 

[JeffSNC]

I've seen that but page 21 says that is to protect the motor; not plumbing or other pool components since motor temp does not correlate directly to the outside air temp.

 

[mas985]

That is true it is measuring the motor temp but that still should be more than sufficient to protect the plumbing from freezing. It takes many hours for the water to freeze in the plumbing and it is less time than it takes the motor to cool off to ambient temperature and restart again so I think it would be fine to use as freeze protection.

What is your typical low temperature and how long does the temperature stay below zero? Often times people use freeze protection when it isn't really necessary: The Physics of Freezing and Freeze Protection

But if you insist on using a timer, do not control the power of the motor with that timer but use the dry contact relay controls (page 16) instead. Powering on and off the motor that way can send transients to the drive which could cause failures and might be responsible for the behavior you are seeing. VS pumps should always be directly connected to the mains power and powered up at all times.

 

[ajw22]

I've seen that but page 21 says that is to protect the motor; not plumbing or other pool components since motor temp does not correlate directly to the outside air temp.

Things don’t freeze that quickly. Read The Physics of Freezing and Freeze Protection

The freeze protection box you are using is old school from before pumps protected themselves.

 

[JeffSNC]

Thanks, this is good info. So my thinking is...

- Just leave the timer on all the time.
- Use the motor freeze protection for temp issues.
- But I think I still need to fix the issue as it'll keep tripping if I cant disconnect it altogether (which i probably could but would need to hire someone I think).

Our tems are usually not bad (Charlotte, NC) but last yr for example we had single digits for a few days and had a pretty solid layer of ice on the pool (though water was flowing in the pipes underneath .. so that makes me nervous.

 

[mas985]

- But I think I still need to fix the issue as it'll keep tripping if I cant disconnect it altogether (which i probably could but would need to hire someone I think).

If the timer pump relay is on all the time so the pump drive always has power, I don't think it will affect breaker anymore and it should not trip. Try if for a few days and see what happens. But make sure you set up the pump low temperature settings.

BTW, is the timer power (not the pump relay) wired to the same breaker as the pump?

Do you know what size breaker is used for the pump?

 

[JeffSNC]

Yeah, looks like that's right, timer on all the time seems to negate the thermostat issue from my test so far, will keep an eye on it.

Timer power does seem to be wired to the same breaker (as the clock will stop when the breaker is tripped).

Not sure on the size, have to take a look.

 

[tstex]

Re that ecostar, make sure it's on its own 20amp DB GFCI breaker, preferably the Siemens [SqD is the next best]. If you need a model number, let us know.

W all the noise the VSP give off [VD harmonics], they can trip GFCI breakers in the 4-6mA range. Siemens has a 6mA range while most others have 4-5mA. Also, if you can keep you panel and VSP out of the direct sun in Spring/Summer/Fall hot times, that's a good practice...