I think the low setting on my 2 speed pump isn't enough

[kevreh]

So, I finally wired up the 2 speed relay for my pump. Messed around with it this weekend running both low speed and high speed. It seems like low speed isn't adequate. observations;

- When running, there's a big air cavity in the filter area of the pump intake, which tells me either not enough water is coming in or too much is leaving to keep things in balance.
- Water is coming in, but barely any is coming out of the returns when I put my hand over them.
- Water flowing into skimmer baskets (2) is barely moving.

I am not using solar when testing and the de filter has recently been backwashed. For solar I can have my suntouch switch the pump to high speed. I'm a little surprised that low speed is so lame. Do others run into this where they can't use low speed?

Having a VS pump would give solve this, just not in the budget now.

Thanks-
Kevin

 

[duraleigh]

I think you are stuck. Low is Low. Air appearing in the pump basket lid on low is common. Does the air go away when you switch to high?

 

[Bama Rambler]

It's common to have air in the pump strainer basket when running the pump on low speed. Unless there's air building up in the filter and/or coming out the returns, I wouldn't worry too much about it.

How many returns do you have?
What size are the return eyeballs?

I see that you have replaced the motor on your pump with a smaller 2-speed one. What is the service factor on the old and new motors?
Did you also replace the impeller with the recommended model for that motor?

 

[kevreh]

I think you are stuck. Low is Low. Air appearing in the pump basket lid on low is common. Does the air go away when you switch to high?

Yeah, it does. That's what caught my attention at first. Surprising thing is my equipment is only 15 feet from the pool, and pretty much at the same elevation. I guess if I had a higher HP pump this wouldn't happen. But then my pump would be too powerfull on high when running solar or the booster pump.

 

[kevreh]

It's common to have air in the pump strainer basket when running the pump on low speed. Unless there's air building up in the filter and/or coming out the returns, I wouldn't worry too much about it.

How many returns do you have?
What size are the return eyeballs?

I see that you have replaced the motor on your pump with a smaller 2-speed one. What is the service factor on the old and new motors?
Did you also replace the impeller with the recommended model for that motor?

When you say you wouldn't worry about it, does that mean to use the low speed? If low isn't really helping to keep the surface skimmed, and it won't run when the solar valve is open, then maybe I'm better off not using it.

2 returns.
No eyeballs, haven't used them in a couple years. But 1-1/2".
I'm not sure about the old motor, its' long gone, but the new motor is 3/4hp, with a 1.5 sf and total of 1.13hp. That's coming from the label on the pump. If I had to guess, the old motor was 1hp, and I replaced it with a slightly lower HP because of the service factor.
I did not replace the impeller. Whats the side effect if you don't? That may be playing into things.

 

[Jimrahbe]

K,

That is why they invented the variable speed pump...

Jim R.

 

[mas985]

Some questions:

- When running, there's a big air cavity in the filter area of the pump intake, which tells me either not enough water is coming in or too much is leaving to keep things in balance.

Is there air at the start of the low speed cycle or does it develop over time?

- Water is coming in, but barely any is coming out of the returns when I put my hand over them.

What is the filter PSI on high speed and then low speed?

- Water flowing into skimmer baskets (2) is barely moving.

Is water traveling over the weir door or around the sides? I have a 1/2 HP pump and on low speed the water just barely goes over the top of the weir door in both skimmers.

What is the Hayward pump line (e.g. SuperPump)?

 

[kevreh]

Some questions:

Is there air at the start of the low speed cycle or does it develop over time?

Once the pump switches from high to low it takes a good 10 minutes to fill with air. On that note I went out to watch the pump cycle from high to low and did notice there's air bubbles coming into the pump. Its just less noticable at high speed. So airs getting in somehow, maybe the union leading to the pump or one of the jandy 3 ways or something leading to the pump.

What is the filter PSI on high speed and then low speed?

High- 15psi, Low- 2psi.

Is water traveling over the weir door or around the sides? I have a 1/2 HP pump and on low speed the water just barely goes over the top of the weir door in both skimmers.

What is the Hayward pump line (e.g. SuperPump)?

It is going over the door, slightly. Its an AO Smith two speed motor and Hayward pump body (sp2607x10).

 

[mas985]

It sounds like the flow rate is sufficient. Just keep in mind that clearing the surface will take longer than high speed.

But it also sounds like an air leak. The union is a good place to start. The pump lid is another place to look.

 

[kevreh]

Good idea on the pump lid. The gasket is getting a little worn, I'm sure its a $5 item or something.

 

[duraleigh]

No eyeballs, haven't used them in a couple years. But 1-1/2".

Well, that is a big pressure drop. Put the eyeballs back (3/4 or 1/2) and you will see an increase in pressure and surface flow. Why aren't you using them?

 

[kevreh]

Well, that is a big pressure drop. Put the eyeballs back (3/4 or 1/2) and you will see an increase in pressure and surface flow. Why aren't you using them?

Every year I would take them out so I could plug the returns, and eventually I noticed the surface stayed clean without them. So why bother. But your right, with the low pump pressure the smaller diameter of the eyeball should make a difference. Thanks for pointing that out. I love this forum.