So I finished re-doing the feed to a septic lift pump with a proper sized box at the correct height above grade, only to find that the cord set configuration still doesn’t fit…no problem I’ll get a thinner box. But while messing around I came up confused.
This is a lift pump in a two compartment septic tank designed to lift liquid up a couple of feet to the drain field, the whole system professionally designed and installed except for the wiring, which I did. The cord set coming from the pump has three cables, one for the alarm system (in case the pump or switch fails), and two others that are designed so one plugs in and the other piggy-back plugs through the first.
I thought this was for convenience in case you only had a single recepticle or so you could plug both cords into an extension cord in case the underground feed failed. OR in case you wanted to use the other side of the duplex receptical for another purpose.
Since this piggyback set doesn’t quite fit behind the box cover, I thought what the heck, plug each one into one side of the recepticle, they fit then,….but then the pump kicks in and stays on! and when I plug them in piggyback, the pump goes off.
What’s up with this? I’m assuming that the switch (I think it’s a floating mercury switch) is powered by one of the cords, and when it calls for the pump to go on, the piggybacked cord gets energized…but how can they do that with this piggyback plug-in scheme?
Is this the way they’re supposed to work or is there something wrong?
Replies
I'm assuming that the switch (I think it's a floating mercury switch) is powered by one of the cords, and when it calls for the pump to go on, the piggybacked cord gets energized
You assumed correctly here. These cords must be piggybacked for the system to work.
Thanks...but,
Why is it done this way?
Well, one reason is that the pump is therefore standard, and it doesn't matter if you use a float switch or not, use the same pump. Also, it makes it easy to add or remove the float switch, you don't have to hard wire it.
You can buy switches to be hard wired if you want, but that just means more work for the electrician. It's fairly easy to plug it in.
Got it...thanks
sorry I didn't get back with you but Tenpenny told you what I was going to say in very similar terms.
If you have to do so (and know what you are doing!!!) you can cut the plugs off and hard wire the whole mess... but why make it hard on yourself?
Thanks, WHW. Got it all wired nice, plugs in, cover goes on. They start digging the hole today for a 1200 sq addition. (had to get this lift pump thing sorted out because they are going to add 6 - 10 " of fill on and about the septic tank, and will use some topsoil from the excavation for the fill)
Exciting times...this will also be a DIY RFH deal, so I'll be back and forth across this board daily.