Overly hot pool pump motor

[Dfranc80]

Hello,

I have a 14x28 rectangular pool, 3 1/2' to 6' depth. I calculated about 14,000 gallons and roughly 85' of head. Pool piping is 1 1/2” combo of rigid and flexible PVC except at the equipment where it is 2”. A Hayward C4030 cartridge filter and originally a Super pump 2, 1 1/2Hp which died after four years of running too hot. My Generic brand motor now (1.65Hp) runs too hot to the touch as well. Listed Ambient temp is 50C, I measured up to 80C. Voltage reading 238v, and amperage 9.3a (motor is rated 8.5a). The thermal overload does not cut power surprisingly, however if manually stopped, the motor will only restart after it cools off (30 min approx).
My neighbour has same size pool with sand filter and a 3/4Hp Hayward Century motor - original (about 10 years).

WHAT IS THE PROBLEM?

I am desperate to figure out what the problem is and how to resolve it. I fear I will go through a motor every four years (this, being year 4 with generic brand motor). Is there too much friction in the head causing reduced efficiency of water flow? Will a VSP motor make a difference? Can I reduce to 1 Hp motor?

Any comments are appreciated!

See attached photo for setup. Thanks!

 

[JamesW]

What is the pump model number?

If it's SP3015EEAZ, it requires a total hp of 2.0 and anything less will be overloaded.

You can downsize the impeller and that should help.

 

[mas985]

Welcome to the forum!

Is there too much friction in the head causing reduced efficiency of water flow?

I doubt you have too much head loss. Excess head loss reduces the motor's power draw and heat, not increases. How did you calculate 85' of head loss? Hint: It is NOT the sum of pipe lengths and it is not a constant. It depends of flow rate. The best way to determine head loss is to measure pump pressure and suction at the pump.

Most likely the problem is a bad bearing in the motor. This adds more load on the motor and making it run hotter. A replacement motor is an option.

Will a VSP motor make a difference? Can I reduce to 1 Hp motor?

Yes and yes although when you reduce the motor size on a pump, you also need to change the impeller. Unless you meant a new 1 HP pump. But the reason a replacement pump will solve your problem, is because it comes with a new motor which is likely the problem you have now.

 

[JamesW]

I would replace the impeller with a SPX3007C.

 

[Dfranc80]

What is the pump model number?

If it's SP3015EEAZ, it requires a total hp of 2.0 and anything less will be overloaded.

You can downsize the impeller and that should help.

Pump model number is SP3010X15A.

 

[Dfranc80]

Welcome to the forum!

I doubt you have too much head loss. Excess head loss reduces the motor's power draw and heat, not increases. How did you calculate 85' of head loss? Hint: It is NOT the sum of pipe lengths and it is not a constant. It depends of flow rate. The best way to determine head loss is to measure pump pressure and suction at the pump.

Most likely the problem is a bad bearing in the motor. This adds more load on the motor and making it run hotter. A replacement motor is an option.

Yes and yes although when you reduce the motor size on a pump, you also need to change the impeller. Unless you meant a new 1 HP pump. But the reason a replacement pump will solve your problem, is because it comes with a new motor which is likely the problem you have now.

Thanks! I guess misunderstood the concept of head when I read up on it. Anyhow as I understand it, I can replace my motor and impeller (sized accordingly to motor Hp) or get a whole new pump. I will shop around and see what I can find. Thanks so much!

 

[JamesW]

I would replace the impeller with a SPX3007C. Try that impeller with your current motor.

 

[Dfranc80]

Pump model number is SP3010X15A.

I would replace the impeller with a SPX3007C. Try that impeller with your current motor.

It might be my plan B. I would like to cut my energy bill by getting a dual-speed or VSP. Theoretically changing the impeller would reduce force on the motor?

 

[JamesW]

Going to a smaller impeller will definitely reduce the force on the motor. The amps will drop significantly. You can even go down to a SPX3005C for even more power savings.

The SPX3005C will reduce the flow so take that into consideration.

I suspect that it will be enough flow unless you need high flow for some reason.

Maybe get the SPX3005C and see if that works for you. If it's not enough flow, switch to the SPX3007C

 

[Dfranc80]

Going to a smaller impeller will definitely reduce the force on the motor. The amps will drop significantly. You can even go down to a SPX3005C for even more power savings.

The SPX3005C will reduce the flow so take that into consideration.

I suspect that it will be enough flow unless you need high flow for some reason.

Maybe get the SPX3005C and see if that works for you. If it's not enough flow, switch to the SPX3007C

Thank you so much for the help!

It got me thinking, could the pump have a design flaw? In a sense that the impeller was too large for the original Super Pump 2 motor? I mean, the theoretical calculations must have worked out during design, so how could my Super Pump 2 have burnt out on me? I feel like this is a very particular situation.

 

[JamesW]

Do you have a picture of the original motor label?

 

[Dfranc80]

US Motor AST165

 

[mas985]

That is the correct motor size for the SP3010X15A. However, someone along the line may have swapped the impeller for a larger one. Do you know the impeller part# ? It is usually stamped on the side of the impeller.

 

[JamesW]

That's not the original motor. That motor was made in 2017.

When was the pump originally installed?

Who did the motor change?

Do you have a picture of the original motor?

Do you have a picture of the pump silver label with the model and serial number?

If the motor is not loud, the impeller is probably too big.

Was the impeller replaced when the motor was replaced?

 

[JamesW]

I suspect that the motor in the picture is the third motor that has been on the pump.

The original motor was probably replaced sometime before 2017 and the original impeller (SPX3010C) was replaced with a SPX3016C, which overloaded the new (2nd) motor.

 

[Dfranc80]

Here is the timeline. I don’t have a pic of the original motor but I have the silver label pic attached . Pool was constructed in 2013 with the original Super II pump 1 1/2Hp SP3010X15. The impeller would have to be the SPX3010C as per manufacturer‘s spec. I replaced the motor in 2017 (I’m an electrician by trade) along with the shaft seal after my Super II burnt out on me (motor casing and windings were discoloured). I bought this motor because it was quick and cheap as I was leaving on vacay the following day. Since then it’s been running hot every year.
I’m at the point that I am ready to go out to buy the Pentair Supermax VS and I can forget about the past.

 

[JamesW]

Does the impeller spin freely?

There is a model number on the impeller. What is the number?

 

[Randrx2]

I suspect your head is too low, therefore your flow is higher than expected. This is causing more power on the pump. Higher flow=higher power. Do you have a valve down stream of the pump or filter? You can close that down some to reduce the flow and watch your amps go down. DO NOT DO THIS ON THE SUCTION SIDE.

We are having this discussion about pump flow and power in the Depp End forum.

 

[JamesW]

It's not a low head situation.

The impeller is either binding or it's too big.

 

[Dfranc80]

I will get a pic of the impeller tonight and post.