Wiring from cistern pump

[transferguy]

posted by: doktrred

I have a 20 amp circuit that uses 12-2 UFB direct burried, in a run that is approximately 100' going to a small pump house where I have a Square D pressure switch and tank that controls a submersible pump in my cistern. The pump is 110 V-- I forget the rated amperage. This is the only load on this circuit. Due to the ongoing drought here in central Texas I have to haul water periodically. I was using a gas powered transfer pump to transfer water from my 300 gal. trailer mounted tank to the cistern, but it bit the dust. So, I got a small portable Wayne electrical pump to replace it. I would like to put a gfci outlet on the exterior of the pump house taking power from the pump circuit so I can use the Wayne pump close to the cistern, vs. using an outlet close to the house and running a hundred feet of garden hose to the cistern. Is this possible (advisable), and would I need a disconnect somewhere in this circuit? I am not in the city limits , and quite frankly the only code that seems to exist here is the code of the west! I would however, like to do this safely and adhere to code if possible.

Thanks

[transferguy]

posted by: chrisb

I don't see any problems with your plan.

Is the cistern not lower than the trailer so you could just use gravity to drain the tank? I think of cisterns as being in the ground. Is yours above ground?

[transferguy]

posted by: doktrred

Thanks for the reply. The cistern is above ground. We live on a big granite dome Llano county(Enchanted rock-if you've ever heard of it- is about 15 miles south of me), and digging especially with drought is almost impossible. I broke the chain for the trencher that I rented when I ran the UFB for the cistern initially!

[transferguy]

posted by: suemarkp

Branch circuits that contain fastened-in-place equipment (is your submersible pump fastened in place?) disallows general use receptacles or lights on that circuit if the fastened-in-place items use more than 50% of the circuit. So if the pump is under 10A, you're fine. If over, then technically it would be a violation to add a receptacle unless the pump is not considered fastened-in-place. I'd probably not worry about it, but you could use a 3-way switch to cutout the submersible pump when you want to use the receptacle.

A branch circuit to a detached structure required a disconnect. You should install a 20A rated AC Only switch close to where the power enters the pump house.

I would always run xx-3 to a detached building (e.g. 12-3). This would allow 2 separate 120V circuits should you need it, or support a 240V pump. It could also provide a spare wire should you lose one if you only wanted one circuit. This is a minimal cost increase after you've gone to all the work of making the trench.

Mark
Kent, WA

[transferguy]

posted by: doktrred

I'm not sure what fastened in place means exactly. The submersible pump is laying horizontal on two small cinder blocks on the bottom of the cistern, my guess is....... not fastened in place? I wish I had thought of the xx-3 cable when I originally set this up, I will remember the next time though
.
Don't know if it matters, but the UFB enters the pump house, and connects directly to the pressure switch. In essence, the pump house is a doghouse sized box that keeps the pressure switch dry and the pressure tank from freezing, never thought of it as a detached structure, but NEC probably doesn't make any distinction. The 3 way switch is a good idea, but I would need to put it in a weather proof box, as I don't want to have to open the access panel every time I transfer water(I don't have a hinged door on this thing). Good ideas though.

[transferguy]

posted by: suemarkp

Fastened-in-place is not defined in the code. For a pump, I call it fastened-in-place if it is connected to rigid piping (perhaps with unions to help with removal/replacement) or if it is hard wired in place. If it is just one of those drop in pumps with a power cord and flex hose output, I'd say it isn't fastened-in-place.

You could argue that a 4x4 post is a "structure" with the wording of the NEC. Usually, an inspector will want a disconnect at something that looks like a building or shed at the least. Your pump switch isn't a suitable disconnect. The reason for a disconnect at the dog house is if you're servicing the pump or switch, you want to ensure the power is off. A local switch makes that easy to know. If you turned off a breaker back at the house, someone could flip it on unless you use lock-out-tag-out procedures which I'm sure no homeowner does. But you can make the same safety argument if you have to service the disconnect switch, but that's the NEC rules.

Mark
Kent, WA

[transferguy]

posted by: doktrred

Well, I looked at the job I posted about above, this weekend. When I originally posted, I was going from memory (always dangerous)! As it turns out the cistern pump is in fact a 220V 2 wire circuit. So I don't see an easy or safe way of tapping this circuit for a 110V receptacle without the neutral wire. Guess it's back to the drawing board. Thanks for all the help.

[transferguy]

posted by: chrisb

Buy yourself a 240volt transfer pump and install a 240 volt receptacle like a NEMA 6-15

[transferguy]

posted by: sellycrash

Posted by suemarkp

Branch circuits that contain fastened-in-place equipment (is your submersible pump fastened in place?) disallows general use receptacles or lights on that circuit if the fastened-in-place items use more than 50% of the circuit. So if the pump is under 10A, you're fine. If over, then technically it would be a violation to add a receptacle unless the pump is not considered fastened-in-place. I'd probably not worry about it, but you could use a 3-way switch to cutout the submersible pump when you want to use the receptacle.

A branch circuit to a detached structure required a disconnect. You should install a 20A rated AC Only switch close to where the power enters the pump house.

I would always run xx-3 to a detached building (e.g. 12-3). This would allow 2 separate 120V circuits should you need it, or support a 240V pump. It could also provide a spare wire should you lose one if you only wanted one circuit. This is a minimal cost increase after you've gone to all the work of making the trench.

Very enlightening information and broaden my
thank you