messing around with vsf pump settings. Main drain.

[vsman]

Looked into a bunch of old posts- essentially the general consensus is that the main drain is useless. I have 3 returns- 1 from the spa, 1 from the main drain, and 1 skimmer return (2 skimmers- the pipes merge somewhere).
I'm trying to get to the fine balance of minimizing energy costs and expending my own efforts to maintain the pool (aren't we all?).
Shutting of the main drain- I am able to get the pump down to 1700 rpm consuming 255W and see a good flow into both the skimmers. I run the cleaner for 2 hours in the morning at 2600 rpm at 1000Watts and a booster pump (plus how much ever the booster pump consumes). The pump is programmed for 10 hours a day. For a total of apprx. 120kWh per month.

1- Is there any downside to permanently leaving the main drain switched off?
2- Any positives to turning it on when the cleaner is on?

If the answer to 2 is yes- I'm thinking of getting another actuator and turning the main drain on when the cleaner is turned on and then switching it off.

 

[ajw22]

What model cleaner do you have?

 

[vsman]

What model cleaner do you have?

It’s a pentair racer with a pentair boost-rite pump (1 hp).

 

[ajw22]

With a pressure cleaner and booster pump your skimmer and main drain settings and pump RPM make no difference to the cleaner.

I would leave the MD at 10% to 20% open. That should not affect your skimmer flow or pump RPM.

 

[proavia]

Just so we are all on the same page. The main drains and skimmers aren't returns - they are on the suction side... they suck water from the pool. Returns are what returns water to the pool.

That being said, Allen's suggestions will work fine for your pool.

 

[markayash]

I do what Allen suggested and leave mine cracked open just a tad to help circulate the water

 

[vsman]

Follow up questions-
- the filter pump needs to be running when the cleaner booster pump is working.
1- why?
2- what is the minimum rpm/ flow ( to achieve the why in question 1)

 

[vsman]

Just so we are all on the same page. The main drains and skimmers aren't returns - they are on the suction side... they suck water from the pool. Returns are what returns water to the pool.

That being said, Allen's suggestions will work fine for your pool.

Noted- thank you.

 

[ajw22]

Follow up questions-
- the filter pump needs to be running when the cleaner booster pump is working.
1- why?
2- what is the minimum rpm/ flow ( to achieve the why in question 1)

The booster pump picks off water from somewhere in your plumbing. It needs the main pump running to feed water to the pickoff point. The booster pump is not strong enough to handle circulation suction on its own.

Booster pumps were implemented before variable speed pumps came on the scene. I think anything over 1200 RPM should work but you have to see what works on your system where neither pump cavitates or gets starved of water.