Just to be sure that I understand, you plan to have 20/240 at the beach? Yes, you can do what you propose if you decommission the existing circuit. The wire gauge depends on the distance. You need to do calculations for voltage drop. It is is long enough, you will need to use larger conductors.

How far is it from the main panel to the beach house panel?

Yes, it is basically a 20/240 circuit that will be split.

It is 60 ft from the main panel to where the new one will be in the beach house.

And just to confirm, we want to be able to turn off the pump from the main cabin while leaving the rest of the beach house on.

Thanks!

If you want to shut off the pump from the main cabin, but leave the rest of beach house on, I believe you will need to run two separate cables, one for each 20 amp circuit.

- When you install a sub-panel it will be connected to a dual breaker in the panel at the main house. You can shut off individual circuits at the beach house, but you can only shut off the entire circuit from the main house.

- When you use one 12/3 NM cable to connect two 120 volt circuits directly to the main panel (no sub-panel at the beach house) it is call a multi-wire branch circuit (MWBC). To be code-compliant, at the main house panel end it must be connect to a dual breaker or two single breakers with a handle tie. You would not be able to shut off only one of the circuits from the main house.

Bruce

A couple of things you need to be careful about. First, you **MUST** have a disconnect at the beach house. You also need to comply with the maintenance disconnect requirements of the pump (i.e., in site of where it is being serviced or the ability of being lockable). Just running a seperate branch circuit down switched from the main house is NOT going to cut it. You'll need disconnects for both the pump circuit and the feeder to your other loads. It could be a main breaker or some other form of switch that opens all the non-grounded conductors. Note that all the disconnects that serve the beach house need to be in the same enclosure (which can be up to six).

Another possibility would be to not switch the pump from the house side but add a light you could see from the house to remind you that left the pump circuit on.

If you run more than one circuit (which could be single MWBC) you need a grounding system (e.g., ground rods) at the beach house. You can not connect a 240V load to a MWBC so if you need power for the pump you are going to need to provide for multiple circuits.

I assume when you say that it's not buried that it's also not a proper aerial installation. If the cable has just been sitting on the ground it's probably of dubious condition anyhow.

Figure out what the actual load is and run four conductors of an appropriate size (three wires is right) either as wet-rated conductors conduit or in suitable direct burial rated cable (like type UF or USE). 12 guage sounds like it may not be sufficient for the loads involved. What's the HP rating of the pump?

The pump is 1/3 hp 120 volt. I discovered last night that the current circuit it tied into the 15 amp circuit for the kitchen lights! The wire is 12 gauge romex NM-B and has been thre for quite some time. I am surprised it has lasted! Basically all the electrical is getting redone. From the service comeing in on down.

Doing more reading on MWBC I am thinking of running two separate 12/2 circuits down to the beach house and into their own disconnects. Also install a grounding rod.

15A should be fine for that pump. Make sure that you follow the instructions for grouping the disconnects. You can use two two-pole switches mounted in the same box as the disconnects.

"Doing more reading on MWBC I am thinking of running two separate 12/2 circuits down to the beach house and into their own disconnects."

225.30 Number of Supplies.

Where more than one building or other structure is on the same property and under single management, each additional building or other structure that is served by a branch circuit or feeder on the load side of the service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.

*Your situation is not permitted*

"The pump is 1/3 hp 120 volt. I discovered last night that the current circuit it tied into the 15 amp circuit for the kitchen lights!"

That is not necessarily a problem per code.

However, the "beach house" may require several circuits.

210.11 Branch Circuits Required

"Note that all the disconnects that serve the beach house need to be in the same enclosure (which can be up to six)."

First, refer to 225.30 above and realize that with only one supply, you only need one disconnect.

Second, if two or more disconnects were necessary, or in this case cheaper, they do not need to be in the same enclosure.

Third, the six disconnect rule in 225.33 is not giving permission for more than one supply. It is saying that you could put six 20 amp 120 breakers on a 60 amp 240 feeder instead of a "main disconnect". Keep in mind that that feeder would already be protected by a 60 amp breaker at the main house.

225.33 Maximum Number of Disconnects

(A) General. The disconnecting means for each supply permitted by 225.30 shall consist of not more than six switches or six circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switch-board.

"You can not connect a 240V load to a MWBC "

Interestingly enough;

210.4 Multiwire Branch Circuits

(A) General. Branch circuits recognized by this article shall be permitted as multiwire circuits. A multiwire circuit shall be permitted to be considered as multiple circuits. All conductors of a multiwire branch circuit shall originate from the same panelboard or similar distribution equipment.

(B). Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.

(C) Line-to-Neutral Loads. Multiwire branch circuits shall supply only line-to-neutral loads.

Exception No. 1: A multiwire branch circuit that supplies only one utilization equipment.

Exception No. 2: Where all ungrounded conductors of the multiwire branch circuit are opened simultaneously by the branch-circuit overcurrent device.

** See 210.4(B) above which now makes 210.4(C) obsolete according to exception #2**

However, in this case, the pump is only 120v anyway.

http://www.mjobee.com/projects&news/nec%20art%20210.4.pdf

Fred, Ali has died. Apologies, Larry.