So I just opened my pool yesterday and found out I needed a new pump. The pump casing itself had cracked, and had been leaking water into the motor mount, which had slung salt water all over the motor. So not only was the motor seized, but the casing is leaking as well (the pump is 13 years old anyways).
So luckily my utility offers a rebate for efficient VS pumps, which makes them as cheap if not cheaper than a single speed pump, so I'm looking at getting a Hayward SP26115VSP (0.85hp VS pump, although unfortunately it only runs on 115V).
Anyways my questions is in regards to the best way of wiring up the DIG-220 with this particular pump. I had installed the DIG-220 2-years ago to run my single speed pump with the pump relay, and everything was working fine. The pump would come on on schedule, the SWG generated chlorine and I got to enjoy the pool. The only problem is that the new VS pump looks like it has to have power at all times (i.e. the DIG-220 can't just send power to it whenever it wants it to turn on).
So my question is can the pump and DIG-220 be wired independently so the the timer on the pump controls the pump, and the DIG-220 does it's own thing? My concern with this option is that the power to the SWG cell would only be controlled by the flow switch. Is this the case anyways when the DIG-220 is wired to control a single speed pump, or does the DIG-220 know when it's sending power to the pump and only power the SWG (only if there is flow) if the pump is also running, or does it also rely soely on the flow sensor to be the on-off switch regardless of the DIG-220 pump control status? If it knows when it's sending power to the pump (i.e. there are 2 requirements to power the SWG: 1. power to the pump, 2. flow switch) can I simply synchronize the clocks and make sure the pump comes on a few minutes before the DIG-220 is instructed to turn the pump on?
The other option is to use the VS pump external relay control option with the DIG-220 relay. The VS pump has an option to control the pump speed with a set of external relays. It appears that the DIG-220 pump control relay is independent from the DIG-220 power supply (i.e. the DIG-220 power comes from terminal 1&2, which are usually jumpered to terminals 3&4 when using a pump relay). So if I supply 220V to terminals 1&2 like in the wiring diagram for an external timer, and then wire the LV relay for the pump into terminal 3, and out through terminal 5, that should allow the VS pump to be controlled by a low voltage circuit by the DIG-220's built in pump relay (don't need terminals 4&6 since the LV connection only switches one leg of the LV supply from the pump). Does this make sense?
Another question ... is there a minimum flow rate for the SWG cell? i.e. could I conceivably run the pump 24/7 and the DIG-220 24/7 at a lower % to get the same chlorine generation, or should there be a higher flowrate when running the SWG cell (ignoring any concerns with well mixing the pool at a low flowrate). Would this be beneficial over my current schedule of running the SWG and pump (single speed, so full flow) for 8 hours as soon as the sun goes down?
I know it's a lot, but I'm trying to get this all figured out so I can finish up opening. I took the cover off to remove all the plugs before I checked the pump, and would prefer not to have the dirty winter water sitting around in full sun for more time than I need to before I can get it clean. I'm debating on dumping in some bleach to keep it from getting too bad until I can install the new pump and vacuum/filter what's in there, but I worry that it 1. won't get well mixed, and 2. will be a loosing battle because of all the winter junk already in the water just sucking up the chlorine residual as soon as I dump it in.
27,000 gallon in-ground plaster not-heated pool
DIG-220 pool pilot SWG salt system: single manifold, RC-52 cell
Pentair 3/4hp whisper flow pump (WFE-3)(Broken: looking for a new one)
Pentair Cartridge filter (Pentair CCP-420)
Manual vacuum for now, although pool is plumbed for a pressure side system