Running Power to the Pump...

[HiTechTed]

I just put in a shallow well in my garden area and I want to run power to it to hook up a pump. So I'll cut to the chase and give you guys my information...I'm positive that there are a few of you who know electricity enough to tell me if I'm on track here or not.

The well is 20 feet deep and there's at least 8 feet of water in the pipe. I set things up so that I can put the pump in my garden shed, to keep it all out of the weather.

I haven't accurately measured the distance I need to run the wire to the pump but I know it's not more than 400 feet, so let's say 400 feet to be safe. I was planning on using direct burial 10/2 wire with conduit anywhere there's a risk of the wire being run over. I was going to run the pump at 240V.

I thought that a 1/2 hp pump would be plenty for the job. From what I have read, the output of a pump that size should be more than enough for our needs.

I would -like- to tap off of my garage power for this run to the garden. I was planning on putting a breaker panel in the garden shed just for the pump. With that said, I would like to have some way of turning off the power to the garden power line from the garage, if anybody has a suggestion. Just in case something bad ever happens, I don't want that line to be hot all the way to the garden without some way of killing the power to it.

I probably didn't use exact terminology here but I think that's everything. If anybody sees a problem with my plan please feel free to share your knowledge. From what I've calculated online, I would have less than a 5% voltage drop even with a 12 or 13 amp load using 10/2 wire over 400 feet at 240V, and keep in mind that my distance will actually be less than 400 feet.

p.s. I can't do solar or a windmill now...I appreciate the suggestions but I have to run wire for now...

 

[leonz]

The problem is that you only have 1.5 gallons per foot for a 6 inch well casing
If it is a 6 inch casing.

Your better off buying a low leverage pitcher hand pump,
drop pipe, sucker rod and the foot valve from Lehmans or
the folks at O'brock windmills in Ohio as the ship everything
a local plumbing shop that has pitcher pumps as the submersible pump will burn out before it gets more water. (been there done that)

 

[mojoinco]

Circuit breaker box in the garage? Yes -- no. Put a switch rated for 208/240/double pole in the garage. This does need to have an appropriate breaker in its path (maybe an appropriately smaller one/fused at the disconnect).

Put a disconnect box (as used for spas/hot tubs/ac units) in the shed. You will likely need a ground rod there as well (a long way from the garage).

Also, you may want to run your voltage drop numbers again. Direct burial will allow for more current capacity, conduit less (heating due to air transfer of heat vs dirt connection for convection). You need to know what chart you used was referencing.