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View Full Version : What size wire for a 60 amp breaker?



boostnerd
09-22-2003, 05:45 PM
Hi All:

I've been researching this and getting conflicting information.

I need a 60 amp breaker added to my panel. What size wire should I use?

Thanks,
Sonny

cope
09-22-2003, 06:33 PM
I would try #6, but #4 may be required. I don't want to be the one to pull it though.:(

echo8287
09-22-2003, 07:19 PM
#6 copper is good for 65 amps,since you cannot buy a 65 amp breaker normally people use a 60 or a 50 amp breaker.
#4 copper is a good deal more expensive and will handle 100amps.

Paul B
09-22-2003, 08:14 PM
Keep in mind you should consider length of the circut when determining the gauge wire. Its been a few years since I setup my shop, so my memory is weak on the calculation. I found guidelines for length in the code book I used for reference.

The first time around, I wired my shop using #10 underground feeder. That stuff is tough to work with, I'd never do it again. Second time around I used 1/2" thin wall conduit with THNN #12 for most everything except the welder, plasma cutter, and stationary woodworking machines.

superarc
09-22-2003, 08:21 PM
don't ask people here but ask a master electrician!

boostnerd
09-22-2003, 08:47 PM
I need to mount the outlet on my garage wall. The breaker panel is on the other side of the wall (outside).

The wire needs to travel 1 ft maybe...if that.

Thanks,
Sonny

cope
09-22-2003, 08:49 PM
Originally posted by boostnerd
I need to mount the outlet on my garage wall. The breaker panel is on the other side of the wall (outside).

The wire needs to travel 1 ft maybe...if that.

Thanks,
Sonny

6-3 will do the job.

Sberry
09-22-2003, 10:07 PM
Yes, 6 will be fine,, are you going to use pipe or cable? I like pipe and 3/4 will do it. I take it this is the main service entrance panel and not a sub? 2 number 6 and a 10 green for ground. At that distance you can use flexable conduit.

ventureline
09-22-2003, 10:14 PM
Simple but to the point, what your after is #6. Forget the pipe, Go with BX cable. It's clean, it bends, it's easy.

Sberry
09-23-2003, 01:34 AM
Do they sell BX that big at box stores? Any 6/2 cable will work. It is just assumed the ground is in it when talking cables. Technically 6/2 wg What machine are you going to run on this circuit? With welding machines rating requirements for wire may be different than breaker ratings. There are a few threads back with some discussions about wiring welders. Wiring for welders call for min wire size and max breaker size. It wont hurt to use bigger wire but the machine may only require 8 ?? especially at a foot from the panel. Do you have manual for the machine you are hooking up?

boostnerd
09-23-2003, 02:02 AM
The machine that I am hooking up is a Miller Dialarc HF. It's a 250 amp TIG/stick machine that can draw over 100 amps when wide open. I don't plan to push it that hard though.

Several people on the board that have experience with this machine have stated that they've had it on a 60 amp breaker and never tripped the breaker.

Can anyone recommend a source for this "BX" wire? I don't recall seeing anything like it at OSH.

Thanks,
Sonny

echo8287
09-23-2003, 02:40 AM
BX wire is armoured cable,with the wire already in it. I wouldn't use it as you would probably be prevented from pulling another wire through it if a problem arose. It also might be hard to find it in a #6. . You will have to go to an electrical supply for it. A welder only needs 6/2 w grd. Depends on how you will run the wire and through what kind of studs etc. whether you would need BX. As far as asking people around here we are all pretty knowledgable about wiring with one exception. I am a licensed electrician in Ga. You would need to check your local codes to be absolutely correct in your wiring practices.David

atucker
09-23-2003, 09:58 AM
Most of the big box stores (at least the ones near me) sell several different kinds of flexible/armored conduit, both metal and non-metal. Handy stuff, bends easy too ;) .

Allen T.

Sberry
09-23-2003, 10:55 AM
Yes, if you undersize the wire you need to match the breaker to wire size just like you are planning on doing. When the machine is wired to full potential the relationship of breaker to wire sometimes changes, but thats not the case here. Pontiac quoted the code section that pertains to single outlet and dedicated requirements for motors and machines where the maximum load of the machine provides the overcurrent protection for the wire itself and the breakers function primarily becomes protection for short circuit interuption. A water well is a good example of this setup as well as some compressors. They are on a dedicaed line. A 1 hp well with a draw of 6A at 240 may be on a 12 or 14 wire with 30A fuses. Its start up load is high but its run current is low. Its own thermal protection is going to limit draw and protect the wire from overheating but it needs a larger breaker or fuse to keep it from tripping on starting.

boostnerd
10-07-2003, 07:37 PM
UPDATE: My house currently has 100 amp 240v service. After some phone calls to the local electric company and a visit by one of their techs, they determined that my "box" and input wiring is capable of supporting 125 amps with a new main breaker. I just need a permit from the city.

I purchased a 70 amp breaker for my welder (Miller Dialarc HF -- will draw 89 amps maximum). This machine is capable of 310 amps output. I don't realistically ever see myself going much over 200-225, so I think a 70 amp breaker will do the job.

I've located some 4 gauge wiring and some conduit for the job. So far, I'm set.

PROBLEM: I cannot find a service receptacle with a rating higher than 50 amps. Home Depot has a lot of Leviton receptacles (mostly stuff for the dryer), but they are all 50 amp max. They are also "ungrounded".

Sonny

cope
10-07-2003, 07:57 PM
If the plug matches, get it.

boostnerd
10-07-2003, 08:03 PM
cope:

If my circuit breaker is rated at 70 amps and I have a receptacle that is only rated at 50 amps, will the receptacle "give out" first and cause me problems in a high amperage situation?

Thanks,
Sonny

Sberry
10-07-2003, 10:12 PM
No, you cannot use the 50 recept on that. Go to a regular electric store. Be prepared for sticker shock though. Your best bet if you want to fully power this machine is hard wire right to the breaker, but you cannot do it if you cant see the panel, like if its on the other side of the wall. You have to provide some visable disconnecting means and most of the time with machines at home it is the cord and plug. Find a main lug 2 pole disconnect with a breaker, or you could use fuses. If you used 50A, 6 wire and a 6 50R it would work, just wouldnt have full power.