Wire Size For A 60 Amp Breaker ,.According To The NEC ??

[MAX-24-Dean]

"Is there EVER a situation where it is legal to run a 10 gauge wire into a 60 amp breaker?

Yes, For the Rating of individual motor circuits, Article 430.52 in the NEC states that when using an inverse time circuit breakers to use 250 percent of the full load current. example; 24 amps of calculated full load motor current multiplied by 2.5 (250 percent) equals 60 amp inverse time circuit breaker.

The heat pump or air conditioner should have the fuse/breaker size you should use on a label fastened to the unit.
Refrigeration equipment Circuit breakers have a multiplier of 1.75 (175 percent of current rating). If the 175 percent can't start the load without tripping you can use up to 225 percent of rated motor current to size the breaker.

 

[4570Man]

If the panel breaker was sized for the 10 gauge wire and the 10 gauge wire is adequate for the load it would be alright. If the 10 gauge was being fed by a proper 30 amp breaker and then the 10 gauge was feeding a second 60 amp breaker which appears to be the case it’s fine. The 60 amp breaker is useless but it’s not going to burn the wire. Now if you were supposed to have a 60 amp supply that’s another problem.

 

[grsthegreat]

Electric heaters suck for electricians..... especially when trying to power house with generator. Most electric furnaces i encounter have 2 circuits run to the unit. One circuit powers fan and primary heat strip, the other circuit powers secondary heat strips. Usually, the actual draw from these circuits is around 42 amps from studying nameplates. But since electric space heating is required to be protected by 125% of the total load (NEC), they need a 52 amp breaker. The next sized breaker is a 60 amp. I agree until the supply breaker size and the equipment nameplate are checked, no one can determine if its wired correctly.

 

[LD1]

Lots of guessing in this thread.

Without knowing the breaker rating in the main panel....it cannot be answered.

You shouldnt have to remove cover. In your main panel, I doubt there are very many double pole breakers. Turn them off one at a time and see what they go to. Range, Water heater, dryer, HVAC, etc. (good time to label for future reference).

If its indeed fed with a 30a, you should be good.

Your worry of things going bad in the future and some other electrician dropping in a larger breaker.....well, not if you hire a competent electrician. Wires are frequently upsized based on circuit length and voltage drop. No electrician in their right mind is gonna pull out a 30a breaker and drop in a 60a breaker just because the few feet of wire in the panel is large enough. They will verify the circuit in its entirety.

When wiring 20a generic wall outlets.....if the outlets are on the opposite side of a large barn/garage, its not uncommon to wire 10ga to the first outlet, then daisy chain the rest with 12ga. It would be foolish to look in the panel and see the 10ga on a 20a breaker and assume the rest of the circuit is also 10ga

 

[Sberry]

Lots of comments and only a couple actually know wtf they are doing. Depending on the connected equipment a 10/60 may be legal, itys listed on the unit. Depending on wiring methods 10 is generally the max legal limit on a 60/ Many common home sizes are powered by 12/40,,, very common. This goes along with earlier threads, so many have learned, read or more likely quote hearsay ( I was always told) is the first clue. The statement, the breaker only there to protect the wire is one of the most eronious quotes in the electric industry and the sure sign the handyman is not really an electrician.

 

[grsthegreat]

Lots of comments and only a couple actually know wtf they are doing. Depending on the connected equipment a 10/60 may be legal, itys listed on the unit. Depending on wiring methods 10 is generally the max legal limit on a 60/ Many common home sizes are powered by 12/40,,, very common. This goes along with earlier threads, so many have learned, read or more likely quote hearsay ( I was always told) is the first clue. The statement, the breaker only there to protect the wire is one of the most eronious quotes in the electric industry and the sure sign the handyman is not really an electrician.

I have No idea what your trying to say

a breaker can be 125% oversized as long as theres a fused circuit further dowm protecting the equipment. But wire size has max NEC loads. If the equipment has a momentary 50 amp draw than runs at 20 amps… like a welder can… i have seen legal situations where #10 wire is attached to 50 amp breakers. For welders only. But on real world this hardly ever happens. Inspectors want circuits protected by proper breaker and wire sizes as no one knows what will be plugged into that circuit down the line.

 

[LD1]

The statement, the breaker only there to protect the wire is one of the most eronious quotes in the electric industry and the sure sign the handyman is not really an electrician.

Then enlighten us "handymen" and tell us what the breaker is there for?

 

[Sberry]

I would be glad to.

 

[Sberry]

The breaker is there for short circuit protection. Its also an off/on switch. The reason is is larger on these types of circuits is that is is sized so it DOESNT trip. The thermal protection in this circuit (different than general circuits with multiple outlets) is provided by the calculated load on the nameplate. The machine draws 15A, its on a 20 or larger wire, it doesnt overheat, its the calculated load. It needs to be sized within a certain parameter,,, small enough it will trip in the event of a fault or a short circuit. Welders are sized this way and an electric range puts all, should say most of the fundamentals of basic circuit design in play.
Any wire in it not rated for fault on 50,,, generally 12 within a range has an additional fuse such as a clock and electronic controls. The rest o9f it wires each element with number 12, more than the element draws, the total of these wont overheat the cord they are all connected to, the 50 allows enough current to pass, in the event of a short it will trip.

 

[Sberry]

In a common general circuit with multiple outlets it protects the wire for thermal as well as short circuit which is its main/second function. Not that it wouldnt trip thermal in other types of circuits but for this type of discussion its not really part of the design criteria and irrelevant,,, this is general and basic.
AC welder designed this way. In many cases wire size is increased within the machine instead of other methods, just as cheap to up it from a 16 to a 14 to meed short of 30 circuit.
This is why code and ul rate some of the light circuits,,, says only 120 and maybe 20A,,, this is because all the approved fixtures are 16 wire (again a load calc based oin the fact that the lamp base restricts the current, they only make lamps wont overload a fixture wire.
A common power strip utilizes this to some extent. They have 15A thermal overload, where lighter wire is used to power multiple outlets it must be protected. On a strip if one looks it says thermal breaker or thermal reset,,, it may trip on fault bu8t that is the primary function of the breaker. UL and Nema specs that anything that plug in to 120V be rated for fault on 20A, the breaker is the fault protection within the equipment if no additional is provided,,, this is different than simply overheating, if it has potential for that designed for it, additional resets like motors not protected other way has.