How to connect 6/3 wire to 12/2?

Question

I have inherited a wiring problem that I am trying to understand/solve.

The previous owner had a 6/3 wire run from a 50AMP breaker in the junction box to his hot tub. Spliced into that run was a 12/2 wire that provided power to an out building.

When the previous owner took the hot tub, he flipped the breaker and cut the wire at the entrance to the house (left it exposed...really nice!) and the cut it at the splice to the barn as well.

So, in anticipation of replacing the hot tub someday and needing power to the barn today, I 'assumed' that the previous setup was the way to go. So I ran 6/3 from the breaker to the hot tub area and added a box to contain the splice to the barn (wasn't there before, just exposed wires under the deck.)

I have no clue how to connect the 6/3 (black, white, red and copper) to the 12/2 (black, white, and copper) safely.

I know the white is neutral, and the black and red is hot, and the copper is ground...coming from the panel...what I dont know is how to connect the 12/2 properly to feed the barn what do I do with the Red wire?

Answer 1

Your 3 # 6 is connected to a 50A. 2P. breaker. That's OK.

Your 2 #12 needs 20A. protection at the tap.

If you want to do it right, get a 30A 1 P. fuse block, with a 20A.

fuse in a weatherproof enclosure.

Tap either 'hot' leg of the #6 feed to one side, and the black of

the 2 #12 to the other. (A short #12 pigtail is permitted.)

The white neutrals can be directly connected.

That protects your barn feeder.

It's a bit sloppy, but it's safe.

Answer 2

You don't!

First things first, the #6 is provided with greater overcurrent protection than you can run a #12AWG conductor on.

Next, why in the world would you want to install a cable assembly w/o a grounding conductor?

Third, it is very likely that the 6-3 was installed for either a single 240 Volt application, or 2 separate circuits. Better find out what its original installation is like before you go messing with it. If it was to run 2 circuits to the barn, then you should have a panel w/a disconnect and a grounding electrode at the barn. You may have the whole installation scheme figured incorrectly, and it probably wasn't correct to start with.

That brings me to my final point. HIRE A QUALIFIED, licensed electrical contractor to run the new wiring correctly. OR, buy lots of Life Insurance, not just for you, but for everyone else in your family. I'll happily allow you to name me as the beneficiary.

I just had an additional thought. If you no this is an "accident waiting to happen", why not take the opportunity to prevent the accident in the first place?

Answer 3

You made a mistake in running 6/3 to the 12/2.

6/3 is rated for 60 amps at 120/240 volts, 12/2 is rated for 20 amps, 120 or 240 volts (not simultaneously).  Mixing wire sizes is Mickey Mouse, and shouldn't be done.

In your main panel you will have to splice the 6/3 to some #12AWG jumpers to feed it with a 20 amp breaker, again-Mickey Mouse!

Call an electrician to do this correctly.  I'm sure the 12/2 out to the shed is not installed properly either.

This whole thing sounds like an accident waiting to happen.

PLEASE-CALL A PRO.

Answer 4

6/3 is over kill for a 20 amp circiut but if its existing and you want to use it it will work. you need to remove the 2 pole breaker and install a single pole 20amp breaker and hook up either the red or the black, you choose that will be your hot. then hook up the black from your 12/2 to your hot. then wht. to wht. and grd. to grd..

Answer 5

The basic problem I see here is that whenever you have a change in the intended use of a circuit, you need a breaker placed on that segment that will reliably trip when the weakest wire is overloaded.  

So if the 12/2 will only carry 20 amps safely, but the 6/3 will carry 50 Amps before it trips, then you need a device to install at the point of the splice that will provide a 20 amp breaker.  You can buy these at a home products store.  An exterior grade breaker box that you can run the 6/3 out to, and then branch off a 20 amp circuit.  But now the problem you have is that you just consumed 20 amps of your total 50 amp run to the hot tub.  You need to know that now the remaining capacity of that run is down to just 30 amps.  so, if you plan to put a hot tub back in someday, you'll either need to downgrade the 20 amps to 15 and then find a tub that only needs 35 amps, or run a separate line out to the barn from your main panel at that time if you'll need the full 50 amps to the hot tub again.

But for now, if you get a box rated at 50 amps that has a slot for a 15 or 20 amp breaker, you can branch out at that point to the barn, since the rest of the 50 amps on the 6/3 run is not going to be used until you get a new tub.

Disclaimer:  I am not an electrician, so please confirm anything I have said with someone who knows what they are talking about.  

Answer 6

You need to terminate the 6/3 in the box you installed with wire nuts and tape. Save til you have hot tub (disconnect required if not in sight of supply breaker). Begin at the barn, run a new 10/3 or 12/3 wire to your power panel. (longer distance use the 10/3 to allow for voltage drop). Supply the barn wire with a maximun 20 Amp breaker reguardless of either size wire. The fuse or breaker size is deturmined by the smallest wire size used in any combination. Most recripcles are only rated for 15 Amps unless you buy 20 Amp rated recripcles.

Over powering a wire size will cause a fire before the breaker would trip.

**JD