Can I replace my 1 hp Super Pump VS motor with a .85 ELV08c?

[rhino942]

Hi,
I have a 1 hp 115 v Hayward Super Pump SP1607 with 1-1/2" pipe and need to replace the motor. Any thoughts on this ELV08c replacement? https://www.regalbeloit.com/brands/Century/products/pool-and-spa/VGreen-Variable-Speed-Motor
Am I crazy to downsize to the .85 hp?
I could rewire to 230v if that makes sense and change impeller to 1.5 hp to go with the ECM16, but I'd rather not.
Help me decide and thanks.

 

[mas985]

As long as you don't run above 3200 RPM, you should be ok. The SuperPump SP1607 is a full rated 3/4 HP pump with a THP of 1.0 so technically, the VGreen 0.85 THP is too small. But if you cap the RPM at 3200, then the effective THP drops to about 0.85. The alternative is to downsize the impeller by one size.

 

[rhino942]

Thank you Mark,
your knowledge of equipment is wonderful and so helpful. I'm waiting on parts to upgrade the pump down to a SP2605, 3/4 HP and going with the ELV08c.

 

[JamesW]

I would go with a 1.65 hp vs motor and impeller.

That way you can run at a slower rpm and the pump will be much quieter.

 

[fishwater]

I’m curious to see your results when you change over. Having just received my electric bill after running my 1hp Super Pump 24/7 for a month I’m ready to make the change to a VS motor as well.

 

[kevreh]

I would go with a 1.65 hp vs motor and impeller.

That way you can run at a slower rpm and the pump will be much quieter.

James, I’m in a similar situation as the OP but my Hayward pump is up rated .75hp (uct1072). Guessing if I go with 1.65hp I would never want it to be at 100% as that may be way too much throughput for my system. May even cause a leak if there’s a weak part of the system. Basic math, I would never run it at more than 50%?