power to boathouse

**LOTW** · 12-29-2010, 11:24 AM

I want to run power to a boathouse about 100 feet from a cabin. I want three outlets and two interior lights. Outlets would be used for charging a boat battery and occasional small tools. All can be on one circuit and I would prefer to avoid a subpanel unless very beneficial or necessary. Would 12 guage wire suffice with a 20 amp GFCI breaker? I would use direct burial wire and still run it through a conduit. Any advice appreciated.

**jwelectric** · 12-29-2010, 12:22 PM

Install one twenty amp circuit using #12 THW conductors would be fine. Be sure to use an insulated equipment grounding conductor with this circuit.

Should you decide to run more than just one circuit a panel would be needed and a grounding electrode system installed. The neutral would need to be isolated and the equipment grounding conductor bonded to the grounding electrode system.

I hope this answers you question but if not please let us know.

hj · 12-30-2010, 08:38 AM

He could also use 12/3 w/grd, employing a shared neutral and a two pole breaker.

**LOTW** · 12-30-2010, 10:14 AM

Thank you gentlemen. What would the advantage be to using the 12-3 wire over 12-2 wire? Is it just a way of having more power at the boathouse if I ever need it? I am thinking that the cost difference would not be too great for the 12-3 materials (less than $100) so if there is an advantage I would certainly consider it. I apologize for my ignorance re 12-3 wiring but once the 12-3 was brought down to the first box in the boathouse, would I continue to use 12-3 for the other boxes in the circuit or would I switch to 12-2?

**cacher_chick** · 12-30-2010, 03:07 PM

The boathouse is considered an outbuilding so you can only have 1 circuit unless you install a subpanel.
Following the thoughts of jwelectric would be correct.

**LOTW** · 01-03-2011, 07:01 AM

Thanks again. I will run a 12-2 wire after the ice melts in May.

**Speedy Petey** · 01-03-2011, 01:17 PM

In this instance a 12/3 multi-wire (shared neutral) circuit is considered ONE circuit in the eyes of the code and a much preferred way to go.
That one extra wire will give you an added circuit and will will lessen voltage drop as long as the loads are balanced as much as possible.

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.