DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   Wiring a receptacle for a lift station (http://www.diychatroom.com/f18/wiring-receptacle-lift-station-78918/)

hydrogeo99 08-16-2010 03:06 PM


I have a lift station next to my septic tank that pumps effluent to the drainfield. The lift station is a precast concrete structure with a 120V pump and float switch…the float switch has a 3-prong cord that piggybacks the pump cord. Obviously, these both need power at the lift station. The original owners had run a dedicated power line to the pump station and just stuck a receptacle box on a PVC conduit next to the pump station. The cord from the pump and float switch just came out of the ground next to the pump station and plugged into the outlet. This was unsightly, and in addition, the PVC conduit had broken at some point, leaving the receptacle box dangling from the PVC conduit. The power cord for the pump/switch was not protected and now the romex that brought power to the receptacle was exposed. I dug a hole next to the lift station and set a GFCI receptacle in a PVC box and inside a water meter type enclosure so I would have access to the receptacle but it would remain out of sight. That worked fine for some time, but on occasion (when it rains a lot) the GFCI trips when too much water gets into the meter box enclosure.
So…I’ve been trying to find a better way to provide power to the lift station. I thought of just installing a junction box inside the lift station for the receptacle and then plugging the cords to it, but believe that would probably be considered an explosive environment…so that's probably not the best way to do it. Does anyone know of any type of sealed or explosion proof enclosure that would allow me to install the receptacle inside the lift station? I've posted in the plumbing forum as well since this issue has both plumbing and electrical aspects. Thanks,
Tony

2 threads on same issue merged
Moderator

mpoulton 08-16-2010 08:58 PM

Quote:

Originally Posted by hydrogeo99 (Post 486673)
I have a lift station next to my septic tank that pumps effluent to the drainfield. The lift station is a precast concrete structure with a 120V pump and float switch…the float switch has a 3-prong cord that piggybacks the pump cord. Obviously, these both need power at the lift station. The original owners had run a dedicated power line to the pump station and just stuck a receptacle box on a PVC conduit next to the pump station. The cord from the pump and float switch just came out of the ground next to the pump station and plugged into the outlet. This was unsightly, and in addition, the PVC conduit had broken at some point, leaving the receptacle box dangling from the PVC conduit. The power cord for the pump/switch was not protected and now the romex that brought power to the receptacle was exposed. I dug a hole next to the lift station and set a GFCI receptacle in a PVC box and inside a water meter type enclosure so I would have access to the receptacle but it would remain out of sight. That worked fine for some time, but on occasion (when it rains a lot) the GFCI trips when too much water gets into the meter box enclosure.
So…I’ve been trying to find a better way to provide power to the lift station. I thought of just installing a junction box inside the lift station for the receptacle and then plugging the cords to it, but believe that would probably be considered an explosive environment…so that's probably not the best way to do it. Does anyone know of any type of sealed or explosion proof enclosure that would allow me to install the receptacle inside the lift station? I've posted in the plumbing forum as well since this issue has both plumbing and electrical aspects. Thanks,
Tony

2 threads on same issue merged
Moderator

This is a difficult problem to solve in an aesthetically satisfying manner. Your original solution was convenient, but definitely not code compliant (or safe). Remember that the wires feeding the GFCI receptacle are not protected by the GFCI. When that hole fills up with water and submerges the receptacle, the wires stay hot while under water!

To be safe, you'll need to have the receptacle above ground. Probably the most durable and attractive solution you'll be able to do would be to set a steel tube post, and mount a good sized weatherproof enclosure on it about 18" off the ground. Maybe use a 4" square tube post, and a 12X12X6" enclosure. Run large PVC conduit (probably 2") from the lift station up through the steel post and into the enclosure for the pump cord. Run smaller conduit (probably 1/2", could use NM liquid-tight flex) for the receptacle, and mount it in a box inside the enclosure. That gives you a nicely enclosed dry place for the pump connection, and protects everything from damage. The disadvantage of this solution is that it is moderately expensive, and not necessarily simple to build. It also does not provide a vapor-tight seal between the lift station and this cabinet, but you could make that happen if it's necessary.

hydrogeo99 08-16-2010 09:27 PM

that sounds like the only option I have right now. I'm real limited on distance though...the power cord from the pump/switch only gives me a foot or less from ground surface:

http://i181.photobucket.com/albums/x...9/DSC08419.jpg

As you can see, I'm using an extension cord to provide power until I can figure a way to do this right.

"It also does not provide a vapor-tight seal between the lift station and this cabinet, but you could make that happen if it's necessary."

I think a large conduit from the lift station to the cabinet would certainly allow explosive gases, if present, to travel into the cabinet although it would have to be large enough to allow me to pass the power cord plugs through it. I have seen some type of putty used in smaller diameter conduit (1/2 to 3/4") to create a seal and prevent explosive methane gas from migrating into electrical equipment at landfill sites, but don't remember what it's called or even know where to find it. Not sure if it could be used on larger conduit, but it's typically installed by placing a clean-out type fitting along a section of the conduit, un-screwing the plug, and then packing the conduit with the putty, then re-screwing the plug back in. Anybody know what that sealant is and where I can find some?

Stubbie 08-16-2010 11:31 PM

1 Attachment(s)
http://www.klsupplies.com/images/dra...asin6so-sm.jpgMaybe a catch basin to remove the water in the handhole enclosure. Something like this

mpoulton 08-18-2010 02:04 AM

That underground outlet, while creative, is rather scary! That's an electrified puddle waiting to happen.

Are you sure you can't pull more cord through from the pump? Most have fairly long cords, maybe the rest is just coiled up in the lift station? If so, build a pedestal. If not, then there is no really good or truly code compliant solution. However, here's what I would do:

Get a 6X6X4 or so PVC J-box with a gasket seal. Lowe's carries these. Mount it inside the lift station, as high up as it can go. Run PVC conduit into it for power, and seal the incoming conduit with spray foam. Install two cord grip connectors (Lowe's and Home Depot sometimes carry these - get the right size) in the bottom of the PVC box. Cut the plugs off your pump and switch, and run the cords into the box. Connect them to the incoming power wires appropriately (incoming hot to one lead of switch, pump hot to other lead of switch, pump neutral to incoming neutral, all grounds together). Tighten those cord grips really well, and use silicone sealant on the box cover.


All times are GMT -5. The time now is 05:54 AM.