Pump intermittently stops and restarts itself

[run53]

I am trying to trouble shoot this problem for my FIL. His pump intermittently stops and restarts itself. It only seems to do this in very hot weather (90+ degree heat waves).

Here are my theories of what could be happening but I am looking for help in trying to isolate which of these theories could be the correct one.

#1) During the heat waves, I expect that a drop in power from the power company could be enough to cut the motor. The power drop could be caused by many people using air conditioners on highest settings. This theory holds the premise that the problem only happens during heat waves. However, why the pump restarts itself doesn't seem to fit.


#2) The pump itself is overheating as a result of:
a) bad wiring between the breaker and the pump
or
b) clogged vents in the pump
or
c) motor is just going bad (it's more than 10 YO) - maybe a short or something inside.


If the problem was the motor 0verheating (#2), then why does it only seem to happen during heat waves? I should add in here that the motor itself is very hot to the touch most of the time it runs. I would think that either a,b or c above would cause the problem to happen even if it's only 70 degrees out. Could it be the heat wave temps add to the motor overheating to the point of failure and not when the temps are only in the 70's or mid 80's?

This problem started in August of last year and the pool was closed in September. This year the pool was opened on Memorial Day but this past weekend we had a 90+ degree heat wave (3 straight days). It happened on the 2nd and 3rd days of the heat wave. It always restarts itself automatically.

Any idea to further help trouble shoot this?

 

[jblizzle]

Sounds like the motor is certainly overheating ... as to why ... many possibilities. I think low voltage could contribute or it could be failing capacitors or it could be failing windings.

I had one doing this and eventually it melted part of the back end by the centrifugal switch. So, I would certainly try to figure out why (test the caps?) and fix it if you want to save the motor or start looking for a replacement motor or pump before it becomes a desperate situation.

Seriously consider an upgrade to a 2-speed motor/pump.

 

[run53]

Sounds like the motor is certainly overheating ... as to why ... many possibilities. I think low voltage could contribute or it could be failing capacitors or it could be failing windings.

I had one doing this and eventually it melted part of the back end by the centrifugal switch. So, I would certainly try to figure out why (test the caps?) and fix it if you want to save the motor or start looking for a replacement motor or pump before it becomes a desperate situation.

Seriously consider an upgrade to a 2-speed motor/pump.

Thanks for the input! I'm kinda leaning towards just replacing the pump. However it's my FIL's and he is 83 years old and would not be interested in upgrading anything. It's quite possible the next pump will outlast him :-(

I am trying to be cautious about replacing the pump unless I am pretty certain that is the issue. But unfortunately, like you said, it could be happening for many reasons. The fact that it only seems to be doing it during heat waves is making me think twice.

 

[jblizzle]

Well, then sell the 2-speed to him with the explanation that it will use 50% less electricity running on low speed, even if the pump is on twice as long.

By upgrade I do not mean in performance, I mean in electricity savings.

How big is the pump? Any high-flow water needs? If not, it is possible you could get a smaller 2-speed pump for the same or less money than an oversized single speed.

 

[run53]

Well, then sell the 2-speed to him with the explanation that it will use 50% less electricity running on low speed, even if the pump is on twice as long.

By upgrade I do not mean in performance, I mean in electricity savings.

How big is the pump? Any high-flow water needs? If not, it is possible you could get a smaller 2-speed pump for the same or less money than an oversized single speed.

Ah! I see, he might just go for that.

I don't have his pump details on me right now. I will be going to visit him tomorrow night probably and will get all the pertinent info. He has a very basic set up. 16x32 rectangle IG pool with sand filter, a single return and a single skimmer (maybe bottom drain but can't remember). No high-flow water needs.

I will post his pump specifics when I get over there. When I do, it would be great if you could suggest a replacement 2-speed. It would be much appreciated.

 

[run53]

The other consideration is that I will be doing the pump replacement for him. If I went from single speed to 2-speed, i assume there would be electrical wiring differences and possibly plumbing differences. I was hoping for a straight forward drop in replacement to make things easy on me.

 

[jblizzle]

Determine the voltage that is supplying the current motor (115V or 230V). And get the model and HP and service factor (SF) on the existing pump.

From the sound of it he could use a small (3/4-1HP 2 speed) ... problem is the 115V 2-speeds are difficult to find, if he has 230V then there are a lot more options.

There may be plumbing changes required anyway depending on how the current pump is attached. For the electrical, if you got a pump with a built-in speed selection switch, then the wiring is basically the same as any single speed pump.

 

[CUTiger78]

Only happens during heatwaves and comes back on by itself?

Any chance it's on a load shedding circuit controlled by the power company? I know air conditioners can be on something like this.

Just a thought....

 

[run53]

Only happens during heatwaves and comes back on by itself?

Any chance it's on a load shedding circuit controlled by the power company? I know air conditioners can be on something like this.

Just a thought....

Seems like a possibility but how could I tell if it's on a load shedding circuit?

 

[CUTiger78]

Seems like a possibility but how could I tell if it's on a load shedding circuit?

Well, you could ask your FIL, but at 83, he might not remember. I guess you could call the local power company and see if they were activating load shedding when the pump went off. You might need some info off his power bill, though, like his account #.

Good luck!

 

[run53]

Seems like a possibility but how could I tell if it's on a load shedding circuit?

Well, you could ask your FIL, but at 83, he might not remember. I guess you could call the local power company and see if they were activating load shedding when the pump went off. You might need some info off his power bill, though, like his account #.

Good luck!

Ok, so this is something he would have had to sign up for and would be reflected on his bill. I will ask him to have a look at the bill. Thanks for the idea!