Hayward Super-II Pump Impeller Size for 3HP VS Motor?

[bzbee]

I have a Hayward Super-II pump (Model SP-3015X20) with a 2HP motor that died a few days back. So I purchased a 3HP (3.5 SFHP) VS Motor to replace it on the same pump.

Opened the pump today and was wondering if I should I up-size the impeller. Here is what the pump has now:
Seal Plate: SP3020-E (rated for upto 3HP)
Diffuser : SP3021-B (rated for upto 3HP)
Impeller: SP3016-C (rated for upto 2HP)
Hayward Super II SP3000 Series parts list - Hayward Super II SP3000 Series Parts - INYOPools.com

Would there be any benefits if I replaced the impeller with larger SPX3020-C or SPX3026-C? I am guessing it would effect the flow-rate i.e. give me higher flow at lower rpm. Is that right? Would that translate into better motor efficiency = higher power savings?

While on the topic of replacing the motor, one of the bolts on the motor mounting plate (Part # SP3000-F) is stuck. Whoever installed it had torqued them super tight, I had a very tough time getting three off. The fourth one is worse, it is actually dug into the platisc (as if it was tighetened by a impact wrench or something). Any tips on getting it off without destroying the plate? I have sprayed it some penetrating oil and am letting it sit for an hour and hoping that would help loosen it a bit.

Thanks.

 

[bzbee]

Update: Got the mounting plate off, the penetrating oil worked. The plate is in bad shape on the side facing the motor, lots of calcification and surface cracks all around (pics attached), So I have to get a new plate now, guess I won't be installing the motor today.

 

[JamesW]

I would go with the SPX3026C impeller. That will allow you to run slower for the same flow rate. It will be quieter at the same flow rate.

 

[bzbee]

I would go with the SPX3026C impeller. That will allow you to run slower for the same flow rate. It will be quieter at the same flow rate.

Thanks for confirming. That's what I thought but wasn't sure. Ordering it now, will arrive on Wednesday.
So that's 2 more days for the pool to stagnate and turn a darker shade of green. I gave up on trying to mix it manually. Will just SLAM it after I get the pump running.

 

[jimmythegreek]

Agree swap the impeller out. Once back together a slam will get you clear again. With a larger pump you can get clear water faster if you keep your filter clean.

 

[JamesW]

I would program a maximum speed limit on the motor right away of about 2700 rpm. You really don't want to go to full speed with that impeller.

You can probably run at about 1,200 rpm most of the time unless you need more flow for something specific.

 

[bzbee]

Agree swap the impeller out. Once back together a slam will get you clear again. With a larger pump you can get clear water faster if you keep your filter clean.

Yes, that was one reason I decided to get the 3HP VS motor (over the 1.65 hp). Better flow at lower speeds along with lower noise and, hopefully, lower power consumption.

Got the SPX3025CKIT Impeller Upgrade Kit that includes SP3026C IMPELLER, SP3021 DIFFUSER and SP3021R IMPELLER RING. The kit was only $10 more than buying the just the impeller, so thought I might as well get it so that all the pump internal parts are new.

I would program a maximum speed limit on the motor right away of about 2700 rpm. You really don't want to go to full speed with that impeller.
You can probably run at about 1,200 rpm most of the time unless you need more flow for something specific.

Looks like there is no way to limit the max speed on this motor - Link to Manual
I will just have to avoid using max speed and program the custom speed to 2700 rpm and use that when needed for vacuuming etc that needs higher flow.
For regular filtering etc, I will just set it at 1200 - 1500 rpm, depending on how it performs. Planning to let it run for 12 hrs or more per day.