Wiring for a well house

[montanaspf]

I am re-wiring my well house. The previous owner had run 12/2 wire (no ground wire) from a 100 amp breaker on the service panel to a 30 amp breaker in the yard on a metal stake, then on to the pump house. Along this run were 2 splices covered with electrical tape. At the well house he then ran a wire off one leg of the pressure switch and one wire off the well casing to run a light bulb and heat tape. It looked like an accident waiting to happen.

The pump motor is: 3450rpm, 3/4HP; Franklin Electric Motor, model #2445070117, 3/4HP, 1ohm, 230V, 3450rmp, 6.0amp, 2 wire I plan to use a 60 watt bulb for freeze protection. The distance to the well from the service entrance is ~65 feet. I plan to use 12/2 w/gound in conduit (I already have this wire and want to avoid buying more wire)

Questions:

1. Will a two pole 20amp breaker be sufficient at the service entrance?
2. If I pull a single 12 gauge wire to the well house, along with the

12/2, can I wire in a 110 circuit for a light?

1. How do I wire the circuit at the well house. Do I need a sub-panel at the well house with a 20 amp, two pole breaker and a single pole 15 amp breaker?

Wiring to the pump seems straightforward but wiring for a simple light bulb seems to be adding quite a bit of cost.

[Steve Barker DLT]

You need to run a minimum of a 12/3 wire. And technically, you should set a panel at the well house and treat it as a subpanel with the ground and neutral isolated from one another.

s

[gfretwell]

Use a 240v light bulb

[The Reverend Natural Light]

Or two 120v bulbs in series?

[John Grabowski]

*If pulling wire underground it must be rated for a wet location. Ordinary type NM (Romex) is not. You would need to use type UF or individual conductors such as THWN. It is easier to pull individual conductors into a conduit.

*Yes

*No. All of the conductors should be in the same cable.

*I Think that you will be better off pulling in four #10's and putting a sub-panel at the well house. That way you can have power for your pump with less voltage drop and power for lighting and a 120 volt GFI receptacle for servicing purposes.

*Labor will be your biggest expense. That wire needs to be at least 18" deep in the ground.

[gfretwell]

That is an interesting thing. 300.3(B) actually says

"(B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, OR cord, unless otherwise permitted in accordance with

300.3(B)(1) through (4)."

Since this is all in the same "raceway" does the "or" eliminate the need to have them all in the same cable jacket? If this was 12/2 UF cable and everything else was compliant I might let him go on the THWN neutral. I agree if this is Romex (type NM) it is a no go.

BTW with this fixed in place load (less than 50% of BC capacity) there is no real reason why he can't supply a receptacle and a light from the two legs of the circuit making it a 210.4(C) ex-1.

[John Grabowski]

I know there are several options for him. He could also put a transformer on the 220 line to get his needed 120 volts for a light or as someone else suggested 220 volt bulbs are available. I tend to think of the best way to go and not just minimum code requirements or jerry rigging. If he is going to do all that work digging a trench and running new wiring, he might as well install something that will serve his long term needs and not just for this moment. Sometime in the future the pump may need to be changed out and it may have different specifications. Right now he has a 3/4 hp. The next pump may be 1 hp. If I was specifying this job for a customer I would suggest a 1" PVC conduit underground and #8 conductors connected to circuit breaker panel with a ground rod at the well house. I would also bond the well casing.

I don't think the paralleling of the wire in the same conduit meets the requirement of 310.4

[Wayne Whitney]

You need to read the exceptions, exception (3) basically says for NM and UF, you don't need to have all the conductors in the same cable, you just need them all to go through the same hole when entering a metallic box.

I missed the OP, if he is installing conduit to the well house, why use a cable assembly at all?

Cheers, Wayne

[gfretwell]

Because he already has it. My guess is this is already done

[Stormin Mormon]

I am re-wiring my well house. The previous owner had run 12/2 wire (no ground wire) from a 100 amp breaker on the service panel to a 30 amp breaker in the yard on a metal stake, then on to the pump house. Along this run were 2 splices covered with electrical tape.

SM: 100 amp breaker feeding 12 gage wire is a bit over capacity. 12 ga is rated for 20 amps.

At the well house he then ran a wire off one leg of the pressure switch and one wire off the well casing to run a light bulb and heat tape. It looked like an accident waiting to happen.

SM: I'm with you. Though, it probably worked fine for many years.

The pump motor is: 3450rpm, 3/4HP; Franklin Electric Motor, model #2445070117, 3/4HP, 1ohm, 230V, 3450rmp, 6.0amp, 2 wire I plan to use a 60 watt bulb for freeze protection. The distance to the well from the service entrance is ~65 feet. I plan to use 12/2 w/gound in conduit (I already have this wire and want to avoid buying more wire)

SM: Yep, wire is expensive. Your 12-2 should feed your 6 amp pump just fine.

Questions:

1. Will a two pole 20amp breaker be sufficient at the service entrance?

SM: Yes, that should drive your 6 amp motor just fine.

1. If I pull a single 12 gauge wire to the well house, along with the

12/2, can I wire in a 110 circuit for a light?

SM: A black colored stranded wire sounds good. Make the two blacks hot, and the white a neutral.

1. How do I wire the circuit at the well house. Do I need a sub-panel at the well house with a 20 amp, two pole breaker and a single pole 15 amp breaker?

SM: I'd want a disconnect switch for when you or someone else is working on the equipment.

Wiring to the pump seems straightforward but wiring for a simple light bulb seems to be adding quite a bit of cost.

SM: Do some net search, see if you can find 220 volt light bulbs. Skip the

110 volt sub circuit.