Replacing .75hp pump with vgreen 1.65hp motor

[kevreh]

I know that sounds like a huge step up, but the vgreen .85 motors are hard to find and are pretty much the same price as 1.65hp motors. Below are the reference numbers. My current motor is uct1072. .75hp, 3400rpm, 115v/8amp. Service factor 1.

Questions;

1. Basically, since I don’t need 1.65hp can I just keep my impeller, and if so what would the effective hp be?
2. If I upgraded the impeller, would I then reduce the rpm’s so I don’t increase my system pressure too much?

.85hp motor: Elv08c
1.65hp motor: Ecm16cu

Thanks!

 

[Jimrahbe]

K,

You are worrying over nothing..

You could put a 3 HP VS pump on your pool and it would work just fine..

It is really a variable horsepower pump, so you just adjust the HP to what you want or need at the time.

Thanks,

Jim R.

 

[kevreh]

Thanks for feedback Jim, glad there’s nothing too complicated about this. So don’t switch the impeller?

 

[Jimrahbe]

K,

Let's see what Mark has to say.. Calling @mas985

Thanks,

Jim R.

 

[mas985]

Impellers are fairly inexpensive and there are definitely some benefits to a larger impeller as long as you don't exceed the motor load rating.

- Larger impellers can be run at lower RPM for the same flow rate reducing noise. Energy use tends to be a little less too.

- Large impellers have a bigger vane gap which means they are less likely to clog with debris

- Large impeller have a higher full speed flow rate which can be useful for quick skimming before swimming

If it were me, I probably would upsize the impeller but make sure you get the correct size for the motor.

What is the current pump model# OR current impeller model#?

 

[jamesey]

@kevreh - I just had a similar dilemma as you. Wanted to disassemble my old pump with a single speed 1 hp motor to a variable speed 1.5 hp vgreen motor, but ultimately went a completely different route

I don't know what your budget is, but in my case, it was more economic to replace the entire pump with an off-brand 3 HP VSP. Budget was my main priority and at 1/3 of the price of the industry leaders I just need it to last for a 1/3 of their lifespan

My new pump runs at a very low RPM 24/7 day and I've had no issues

 

[kevreh]

Impellers are fairly inexpensive and there are definitely some benefits to a larger impeller as long as you don't exceed the motor load rating.

- Larger impellers can be run at lower RPM for the same flow rate reducing noise. Energy use tends to be a little less too.

- Large impellers have a bigger vane gap which means they are less likely to clog with debris

- Large impeller have a higher full speed flow rate which can be useful for quick skimming before swimming

If it were me, I probably would upsize the impeller but make sure you get the correct size for the motor.

What is the current pump model# OR current impeller model#?

Thanks mark. My motor was a uct1072 .75hp, 3400rpm, 115v/8amp attached to a Hayward Superpump. Just today I put a new vgreen 1.65 vs motor on the “wet side” with the .75hp rated impeller. My understanding is that with this impeller I’m getting similar gpm as my .75hp motor. Is that correct?

If so, apples to apples at 3400 rpm I’m getting worse performance with the new motor since I’m running the motor at 100%, 240v, and the through-put is similar to my old motor. So if I put an impeller on that’s for a 1.65hp motor, I could run it at about 50%?

 

[kevreh]

@kevreh - I just had a similar dilemma as you. Wanted to disassemble my old pump with a single speed 1 hp motor to a variable speed 1.5 hp vgreen motor, but ultimately went a completely different route

I don't know what your budget is, but in my case, it was more economic to replace the entire pump with an off-brand 3 HP VSP. Budget was my main priority and at 1/3 of the price of the industry leaders I just need it to last for a 1/3 of their lifespan

My new pump runs at a very low RPM 24/7 day and I've had no issues

So by tripling the hp, you’re able to run it at a fraction of the rpm’s?

 

[mas985]

The HP load on a motor is due to the impeller, NOT the rating on the motor. So even though the rating is higher, it doesn't mean that the new motor will use more energy. Most likely, it will use less energy because it is a more efficient motor.

 

[jamesey]

So by tripling the hp, you’re able to run it at a fraction of the rpm’s?

That's right! I have my new 3 hp running 24/7 @ 1500 rpms. While I'm getting less flow at any given moment compared to my prior single speed, I'm circulating significantly more water through my system at a fraction of the electricity cost. It's a no brainer. Wish I did this years ago

I see you're in Virginia (I used to live in Annandale too ), but there might be rebates from Dominion to upgrade to an EnergyStar rated pump. Check it out:

https://www.dominionenergy.com/virginia/save-energy/energy-star-products

If this is true, you could get the same pump I ordered at just under $300. Absolute steal

 

[jamesey]

Oh, forgot to mention to check your specs on your filter. I don't know anything about Carvin filters

You want to make sure your filter is oversized for your pump just in case you do decide to run it at high speeds. It's okay if it's not, just make sure you remember to limit the RPMs so your filter can handle the new flow