Hayward pump/motor temperature (possible mismatch)

[RichSiegmund]

Installed a new US Motor today to replace a 4year old motor that failed (smoke got out).

I'm wondering about two things (and see my NOTE below about the filter replacement)

1) is the mismatch in total HP between pump and (both) old and new motors okay? I'm told the new motor is a direct replacement for the old, and they do have same total HP. **

2) Is the case temperature too high? After running about 30 minutes I measured 200F. The motor fan is blowing hot air, not obstructed at all.


First photo below shows the temperature measurement

** I think (can't remember for certain) that the original motor with the Hayward pump was replaced under warranty when it failed after about 13 months. So it's possible (likely) that Leslie's put a new but lower rated motor in as a courtesy. In any case, the Old motor worked fine for 4 years until 2 days ago when I noticed it was off due to thermal safety switch. Both new and old motors generated powerful enough jets in the hot tub

NOTE - A possible complication is that I had replaced the DE filter with the next size up. Went from a pentair 48sqft to a pentair 60sqft. I think I read in this forum that upsizing the filter is fine. I did the entire replacement myself, I'm pretty certain that there aren't any issues since there are no leaks, filter cleans, jets in pool and waterfall from spa to pool looks normal. HOWEVER -> the pressure guage on top of the filter now reads about 19 psi with the full new charge of DE, whereas previously I think it was closer to 15 psi. I always fully dissassemble the filter, so it always starts pristine and at consistent pressures.


Summary
- could be that the larger filter (with higher pressure) caused old motor to fail within a week (with 30 min daily runtimes, I was on vacation)
- new motor could be being overstressed
- or maybe the high temp I'm measuring is expected with a higher SF motor


Some more details

Old motor: 1.5hp SF 1.10 ( 1.65 Total HP)
New motor: 1.0hp SF 1.65 ( 1.65 Total HP) This is a new motor, from a reputable local service/supply shop in Austin TX, is new (not rebuilt)
Pump casing label: 1.5hp SF 1.6 (2.4 Total HP)



Hayward pump


New motor


Old motor

 

[kadavis]

You need to match motor HP with the pumps impeller. If you use a motor with less total HP than the pumps impeller it will run hot and shorten the motors life. You could check the number on impeller to give you a positive id

 

[JamesW]

The casing temperature is definitely too high. Probably an overloaded motor.

If the original impeller was not replaced with the first replacement motor, then the motor is being overloaded.

You're going to have to check the part number on the impeller.

You're probably going to have to replace the impeller or the motor.

 

[RichSiegmund]

Thanks @JamesW and @kadavis
I'm reluctant to put a smaller impeller in because I'd have less powerful jets in the hot tub.

Is there any reason to think that replacing the 48 sqft DE filter with the 60 sqft should be a factor in this? Seems to me that a larger filter should always be easier to pump water through than a smaller filter, however it appears that the new/larger filter is running about 5 PSI higher than the previous one (which was a pentair also, from around 1997).

I've tried to reach out to Hayward to confirm whether the presence of their 2.4 THP sticker on the pump housing implies that it was originally paired with that motor. Seems likely.... Their support person escalated to their supervisor, now I'm waiting to hear from them.

In any case I think I'll be wanting to get a larger 2.4 THP motor.

 

[JamesW]

The filter is not relevant.

The pump definitely came with a motor that had 2.4 hp.

 

[RichSiegmund]

Awesome @JamesW
Last question, there isn't an exact 2.4 THP rated motor, I can move up to 2.25 or 2.6. The cost difference is minor, so I'm thinking that the 2.6 would be preferable (and it's in stock).

My preference is to move up to the 2.6 (thinking it will run cooler over all)

Am I safe going above the 2.4 THP rating on the pump assembly by about 10%? I'm thinking the primary risk is that when the filter is backed up the motor will be able to increase pressure to a greater degree. But that's already a risk with any motor if I were to let the filter get too backed up.

 

[JamesW]

You have a SP3215EE Tristar pump. It's the same as a SP3215X20 Tristar pump.

The SP3215X20 takes a 2.2 total hp motor.

So, you can use a 2.2 hp motor or you can use the bigger motor if you want.

 

[RichSiegmund]

Success !!

The new motor (2.6 total hp) has been running a few hours now and the max temp I measure (case, around center of label) is 170F. With the smaller motor it reached 200F after about 30 mins, which is when I turned it off.

The larger motor cost me about $370 vs $230.

Thanks for the help @JamesW and @kadavis !!

 

[JamesW]

170 is still a little bit too hot. If it's in the sun, it might be ok.

Assuming you are measuring surface temperature, in the shade, at air temperatures less than
90 F, I would give this as a rough guide:

Below 135 F, good
135 to 150 F, warm
Over 150 F, too hot.

Maybe check the voltage to make sure that it's good.

 

[borjis]

What is a proper temp for a properly sized pool pump motor and impeller?

I know mine get's hot to the touch, but it's worked very well the last 5 years.
would be good to know if 170f is considered good since 200f is too high.

EDIT: thanks James!!!