Air in Salt Generator at Low RPM's Need Help

[traderfjp]

Hi Trader;

I'm not sure what the solution to your problem might be, because I'm not sure what the problem is.

The problem is that when I want to save electricity and use a lower pump speed there isn't enough flow to keep the plates of my salt generator totally bathed in water. I have a canister with the plates/cartridge inside and then the water enters from the bottom of the canister and exits from the bottom of the canister. When I use a slower pump speed I get a large air pocket and only about 3/4 of the plates are submerged in water. This causes the salt generator to trigger the service light which starts blinking. I was told, from the company, that I will ruin the plates if this occurs too often. I guess the system doesn't shut itself off with improper flow.

Solutions: I can turn my generator off and then use the lower speeds but then I won't be making chlorine and it requires me to always run the pump at a 3 or 4 setting which uses lots of electricity. Right now I have my solar panels on and am using a 3 seeting which pulls 800-900 watts. If I can run the pump on a 2 setting I can reduce my wattage to 300 watts.

Another possibility to plumb the canister so the inlet and outlet is on the top of the unit but I'm not sure that would solve my problem. Not sure what I can do.


Many SWCGs have flow switches that will shut down the unit if the FLOW is too low. Some may have current sensors that will shut down if the current flow across the plates is wrong, possibly due to air. Do you know which is happening in your unit?

The service light blinks when there isn't enough flow. I'm not sure if current is then shut off or if this is just a warning that damage will eventually result from operating the unit like this.

It's always *possible* to plumb a pool so that there's no air in the lines, but it's not always *practical*. It depends on current piping, and why you are getting air in there now.

Can you take pictures and send them to poolforum AT gmail DOT com? I'll post them if you do. It would make it much easier for folks to help you. There was no picture link in your post, but in any case, pictures of YOUR pool would be best.

I sent them to your gmail account.

[Poolsean]

The cell is specifically designed to be mounted with the inlet and outlet at the bottom of the cell, so that the flow protection device (which is testing for continutity across two points at the top of the cell) can work properly. The problem is as you found out. Not enough flow to evacuate all the air, will not allow the system to come on. You may try starting the pump on a higher speed to get the air pockets out first, then having it switch to a lower speed, which should continue to keep the air pocket out.
Otherwise, you'll just have to run the system on something higher than the lowest speed.

The problem with mounting it differently from the instructions is the collection of hydrogen gases. If there is not enough flow to send this back to the pool and released to the atmosphere, it can collect at some point within your circulation system and damage equipment.

[traderfjp]

Yes. Running it at a higher speed does get most of the air out but on the lower speed the water level still falls over time and the flow sensor shut the unit down. I think I have a solution. I'm going to install a PVC valve on the outlet of the SWG to create some back flow pressure. When I run the pump on a higher speed I can turn the valve wide open and on lower speed I can throttle the valve down.