12-3 wire on 30 amp circuit???

[Hot shot]

My next door neighbor just bought a generac generator 6500 8000
They just moved in a year ago
His setup is a 30 amp double pole breaker in main house panel
12-3 wire connected to breaker. Other end of wire runs down in crawl space and out crawl space door and has 4 prong plug which plugs into generator it’s not the flat yellow insulated wire it’s white insulated wire
Pretty sure he needs at least 10-3
We lost power early Saturday morning
We live off of a hard surface road with only 6 houses so we will be last on the totem pole

 

[Norcal]

There are applications where 12 gauge wire can be used with a 30A breaker but that generator inlet is not one of them, you are correct in that it should be 10 gauge wire. 12 gauge NM cable is 20A max as it is always sized from the 60 degree C column of table 310.16.....

Left off part of the table number because don’t have the code in front of me.

 

[Terry D]

As Norcal said, needs to be # 10

 

[esvee]

Copy pasting my reply to your thread in garage gallery in case someone else finds this thread:

It depends.

That breaker is probably made for an A/C unit specifically, which would fall under NEC, Art.440, Section III. 430.22E also specifies certain motors requiring a 30A breaker but can be wired with a 12AWG conductor.

https://www.mikeholt.com/mojonewsar...ning-and-Refrigerating-Equipment~20040102.htm

To make that breaker support whatever he wants to plug into it with the assumption there is 30A on the other side then yes the conductors should be 10AWG.

 

[Terry D]

Copy pasting my reply to your thread in garage gallery in case someone else finds this thread:

It depends.

That breaker is probably made for an A/C unit specifically, which would fall under NEC, Art.440, Section III. 430.22E also specifies certain motors requiring a 30A breaker but can be wired with a 12AWG conductor.

https://www.mikeholt.com/mojonewsar...ning-and-Refrigerating-Equipment~20040102.htm

To make that breaker support whatever he wants to plug into it with the assumption there is 30A on the other side then yes the conductors should be 10AWG.

None of that applies to this situation. What you are referring to is for wiring installations for larger motors and A/C compressors and welders and others listed in 240.4(G). All breakers now are HVACR rated. The breaker does not determine if you can use Article 430 or 440, the equipment that you are wiring does. The overloads built in the motors protect the branch circuit wiring from overcurrent, but not shorts or faults, the breaker does this. You are allowed to over size the breaker for start up currents. Any other wiring installations fall under 240.4(D). Maximum overcurrent protection for # 12 copper is 20 amps

 

[esvee]

None of that applies to this situation. What you are referring to is for wiring installations for larger motors and A/C compressors and welders and others listed in 240.4(G). All breakers now are HVACR rated. The breaker does not determine if you can use Article 430 or 440, the equipment that you are wiring does. The overloads built in the motors protect the branch circuit wiring from overcurrent, but not shorts or faults, the breaker does this. You are allowed to over size the breaker for start up currents. Any other wiring installations fall under 240.4(D). Maximum overcurrent protection for # 12 copper is 20 amps

I was suggesting the equipment may have been present when the house was built and is no longer.

 

[Terry D]

I was suggesting the equipment may have been present when the house was built and is no longer.

This is for a generator plugging into a 30 amp receptacle back feeding a 30 amp breaker in a panel

 

[Norcal]

I was suggesting the equipment may have been present when the house was built and is no longer.

I mentioned that there are situations where 12 AWG can be on a 30A circuit the OP’s situation does not fall into one of those, 10 AWG is required at minimum. What was there at one time has no bearing on the requirements for that generator inlet.

Being able to use a smaller conductor on A/C equipment depends entirely on the equipment data plate, but still not part of this situation.

 

[exranger06]

Let me guess...there's no interlock installed in the panel either, right?

 

[Hot shot]

No interlock
Just cutting main breaker off
We are going to change to 10-3
What kind of 10-3 with ground should he get
Probably will need about 35’. Haven’t measured yet
The ice storm we had won’t no joke
I don’t expect to have power for another week

 

[quickfarms]

Let me guess...there's no interlock installed in the panel either, right?

I use these on the main breaker instead of an interlock

 

[walta]

I say don’t touch it if you are not going to make it a code compliant installation.

Without a transfer switch or an interlock it is not compliant. Yes maybe you are smart enough to operate the generator without one of these devices but what will happen when someone else tries when you are away.

How will you feel if someone gets hurt badly?

Walta

 

[wyliesdiesels]

I was suggesting the equipment may have been present when the house was built and is no longer.

Doesnt matter what was there before. He has repurposed this for a generator inlet and thus the wire needs to be sized by the inlet and breaker size.

If the wire is inside the wall and never goes outside, he can use 10-3 NM-b.

Make sure the neutral on the generator is isolated...

Also, need to get an interlock....

 

[Hot shot]

I think we will get the 10-4 soow cord to get through this
Later on maybe run wire underground to where generator will be when running, mount the plug box (don’t know the proper name for it right now) or he might want to just leave the cord in the crawl space when not in use and cut breaker off. In the 14 years I have been living here I think I’ve had to run mine 1 time for maybe 8 hours and once or twice for 2 or 3 hours. I wanna say the last time this area got an ice storm was 20 years ago
Now as far as my generator situation I only have a 5250/7350. I’m tired of having to cut things off to run the hot water heater I also have a well pump which has a pretty big surge and a septic pump. I’m going to upgrade to a 50 amp. Might not need it often but when u need it u need it

 

[Hot shot]

Wylie can u explain how to do that (isolating the neutral

 

[wyliesdiesels]

I think we will get the 10-4 soow cord to get through this
Later on maybe run wire underground to where generator will be when running, mount the plug box (don’t know the proper name for it right now) or he might want to just leave the cord in the crawl space when not in use and cut breaker off. In the 14 years I have been living here I think I’ve had to run mine 1 time for maybe 8 hours and once or twice for 2 or 3 hours. I wanna say the last time this area got an ice storm was 20 years ago
Now as far as my generator situation I only have a 5250/7350. I’m tired of having to cut things off to run the hot water heater I also have a well pump which has a pretty big surge and a septic pump. I’m going to upgrade to a 50 amp. Might not need it often but when u need it u need it

cordage is not permitted to be used as building wiring.

the correct term is inlet...

Wylie can u explain how to do that (isolating the neutral

It varies by brand and model.

youll have to find where the neutral connects to the generator frame and remove it. then you can make a bonding plug where the neutral and ground on a plug are connected. plug this into one of the outlets when the generator is used as a standalone unit (not connected to a house)

 

[TechnoMayor]

Consider installing one of these...

http://www.interlockkit.com/

 

[Hot shot]

Gotcha
Thanks

 

[quickfarms]

Consider installing one of these...

http://www.interlockkit.com/

Those are about $150

Before you order one of those you should check with the manufacturer of your panel to see if they make an interlock.

For an example the Siemens kit for vertical stacked breakers is $27 on Amazon

 

[exranger06]

I use these on the main breaker instead of an interlock

That's still not code compliant, for 2 reasons:
1. What if you forget to install it, or misplace it? Or what if someone else plugs the generator in and they don't know they're supposed to install the lock? An interlock kit is foolproof; with an interlock, it's impossible to forget to turn off the main breaker and keep it off, because you CANNOT turn the generator breaker on unless the main breaker is already turned off.

2. An interlock doesn't only prevent the main breaker from being on while using the generator, it ALSO ensures the generator breaker is OFF when you're using utility power. Imagine you're using utility power, the generator breaker is still ON, there's nothing plugged into the generator inlet. Someone comes along, a young child perhaps, lifts the cover on the inlet, and touches one of the male prongs (which are energized, because the generator breaker is ON while the main breaker is also on)
Are you saying you keep one of those locks on the generator breaker at all times when you're using utility power? Even if you do, it's still not code compliant (see point #1).

 

[alfredeneuman]

I use these on the main breaker instead of an interlock

I used one of those as part of my "Lockout-Tagout" kit. I quit using it because all I had to do was give a little twist and it would fall right off.

 

[Hot shot]

We have decided to hold off and do it properly at a later date
Have another ice storm coming Thursday according to the weather man
Really don’t have time to do it anyway
He works and has 3 kids
I had to go get more gas for generator
We went ahead and got the trees off the power lines so the propane tank can get down the road tomorrow. My neighbor is down to 10% in his tank

 

[quickfarms]

I used one of those as part of my "Lockout-Tagout" kit. I quit using it because all I had to do was give a little twist and it would fall right off.

There are several styles for different breakers and they have to be correctly adjusted. It is also possible that yours is worn out. Mine firmly hold the handle of the breaker and are very secure.