Water pump pressure switch wiring
Asked Nov 8, 2010, 09:47 AM
We lost water pressure in our house last night. We have a well pump 360 feet down. My 1st thought was the well pump has finally failed. I though a moment and remembered there is a pressure switch in the basement so decided to check that. The pressure read only 30. That seemed a little low. I checked the circuit breaker and seemed OK. I turned them off and back on anyway. Two breaker switches, 220 volt water pump. I took the cover off the pressure switch, the contacts were open. I manually closed the contacts my moving the switch contacts forward to make contact. I could hear the water starting to fill up the tank and the pressure go up. I may need a new switch. 14 years old. Seems to be working normal for now anyway.
I noticed there is only 3 wires for this 220 circuit. They used the neutral wire(white) for the 2nd leg of the 220. Is this common? I was trained in electricity in the military and this goes against what I was taught. I always thought you should use a 4 wire for 220 and use red for the 2nd leg.
Not only that, There is a cutoff switch near by. I took the cover off and the switch cuts off the black wire only. This sounds dangerous since the 2nd leg, white in this case, is still hot.I tried using the cutoff switch and the pump still works anyway.
Apparently the pump will work on 110. And yes I verified the cutoff switch definitely is in line to the pressure switch.
I remember noticing the white wire going into the 2nd breaker for the 220 a few years ago when an electrician was working on something else. I asked him then if that was normal for water pumps. He kind of shrugged his shoulders and
Implied it was common.
Should I at least replace the cutoff switch with a switch that will cutoff both legs of the 220 if there is such a thing.