Alright I'm working on the design for my auto-topoff system. The tricky part is that the sump is too low to have its own drain, so I basically have to pump water out. I've come up with two different designs, and I'm not sure if it really matters which way I go, but I wanted to talk it out and see if there are any holes that I'm missing.
So the integral parts of the design will entail a solenoid valve to add water to the sump, a pump to remove water from the sump, a timer and a float switch.
The only variability in the two setups is which component is timed, and which component is switched.
My initial thought was, have the pump on a timer, and have it run for say, 2 minutes per day (or whatever). This will pump X gallons of water out over the duration. The float switch will control the solenoid, so as water begins to be removed, the switch energizes the solenoid and water begins to be added. If the switch fails closed, the sump overflows within a few minutes. If the switch fails open, water level in the sump slowly decreases because no new water is being added.
Second scenario - Have the pump on the float switch (reverse operation) and have the solenoid on a timer. The solenoid opens up for 2 minutes per day (or whatever) and adds X gallons of water. As the water level rises, the float switch energizes the pump and keeps the water level at a given height. If the switch fails closed, the pump drains the sump and burns out my pumps. If the switch fails open, the sump overflows eventually, unless I notice the water level rising daily.
The other variation is to not have a solenoid, but rather a constant drip system adding X gallons per day, and have the float switch operating in reverse mode so when the water level reaches a certain height, the pump energizes and removes some of the water. The only thing I'm uncertain about with this is how much of a window I can get with a float switch, I don't want the pump turning on to remove 1/4" of water, I would want to be able to set a range, say it turns on when the water is 8" high in the sump and turns off when the water is 4" high.
Anyway, sorry its so long, but any and all comments are welcome.
So the integral parts of the design will entail a solenoid valve to add water to the sump, a pump to remove water from the sump, a timer and a float switch.
The only variability in the two setups is which component is timed, and which component is switched.
My initial thought was, have the pump on a timer, and have it run for say, 2 minutes per day (or whatever). This will pump X gallons of water out over the duration. The float switch will control the solenoid, so as water begins to be removed, the switch energizes the solenoid and water begins to be added. If the switch fails closed, the sump overflows within a few minutes. If the switch fails open, water level in the sump slowly decreases because no new water is being added.
Second scenario - Have the pump on the float switch (reverse operation) and have the solenoid on a timer. The solenoid opens up for 2 minutes per day (or whatever) and adds X gallons of water. As the water level rises, the float switch energizes the pump and keeps the water level at a given height. If the switch fails closed, the pump drains the sump and burns out my pumps. If the switch fails open, the sump overflows eventually, unless I notice the water level rising daily.
The other variation is to not have a solenoid, but rather a constant drip system adding X gallons per day, and have the float switch operating in reverse mode so when the water level reaches a certain height, the pump energizes and removes some of the water. The only thing I'm uncertain about with this is how much of a window I can get with a float switch, I don't want the pump turning on to remove 1/4" of water, I would want to be able to set a range, say it turns on when the water is 8" high in the sump and turns off when the water is 4" high.
Anyway, sorry its so long, but any and all comments are welcome.
