Do circuit breakers in series need to be the same amperage?

[alfredeneuman]

Show me in the code where that applies to 6awg feeding a subpanel.

Show me in the Code where the term "subpanel" appears. (It doesn't)

 

[EngineerNate]

Show me in the Code where the term "subpanel" appears. (It doesn't)

You're still lawyering and your original comment still isn't applicable to OP's situation.

You can't feed a subpanel, running general purpose loads, with 6 awg copper, on a 100A breaker.

C'mon man. This argument is the electrical equivalent of me saying, to a person who owns a Toyota Camry with the gas 4-banger, "You can't put diesel in your car." And some guy walking up to us and saying, "BUT SOME CARS TAKE DIESEL!"

It's a verifiably true statement, but the Camry is still going to need it's fuel system flushed if the owner puts diesel in the tank.

If you blindly replace any breaker in any panel, with a higher amperage equivalent, without understanding what's downstream of that breaker, both load wise and wiring wise, you're a goof who has no business in an electrical panel.

"Repurposing a 6 awg feed and connecting it as a dedicated motor feed and sizing the breaker appropriately for that purpose" isn't the same thing.

Cheers,
Nate

 

[alfredeneuman]

This was what you said in post 38

"As has been said several times. If someone after you comes in and does a bunch of boneheaded stuff there's nothing you can do to stop them.
Anyone who puts a 100A breaker on 6 awg copper is incompetent or ignorant enough to do any number of dangerous things that might kill them or burn the house down no matter what you do."

..... with no mention of anything else

 

[EngineerNate]

This was what you said in post 38

"As has been said several times. If someone after you comes in and does a bunch of boneheaded stuff there's nothing you can do to stop them.
Anyone who puts a 100A breaker on 6 awg copper is incompetent or ignorant enough to do any number of dangerous things that might kill them or burn the house down no matter what you do."

..... with no mention of anything else

I've admitted my imprecise language and since attempted to be more specific.

 

[EngineerNate]

Getting back to OP's situation:

As an amateur at best when it comes to electrical, my practice is always to err on the side of more copper/aluminum and smaller OCPD if there's anything even remotely questionable in my mind.

Because I don't know everything and a bit of back pocket margin on wire heat generation and voltage drop hurts nothing but my wallet, and that pain is a lot more temporary than either an electrical fire or having to redo something after I've spent ages putting walls up over it.

But even then, I didn't think twice about feeding my 100A rated subpanel with a 60A breaker and 6 awg THHN copper in pipe, and neither the electrician who did the downstream work of that subpanel or the code inspector had an issue with it.

There's no legal requirement for the breaker in the sub to be the same size and no associated liability down the line if someone does something non-code compliant, so it seems a silly expense for a what-if that is posited on someone doing something outside of what's legal and prudent.

 

[dave*99]

You could print out this entire thread and laminate it to the wall next to the sub panel, add an additional copy next to the main.
This became one of those threads where the first couple of replies made the salient points and then it turned into a urination competition.

 

[RPH]

Doing the right thing and worrying about what someone down the line may do out of their own ignorance are not the same thing.

You can spend all kinds of money thinking it may idiot proof something. It may help, it may not

When you think you have it idiot proofed. Along comes an idiot who proves you wrong.
Anybody can do anything at anytime. I can’t keep the guy that buys my house from pulling the meter and jumping it.
If you don’t understand electricity and how it works. STAY OUT of electrical cabinets and such. Call a pro electrician you trust.

 

[mm08822]

Then that is on them for not knowing what they are doing.

Worrying about a dumb next guy is his problem, not yours

It's like the car commercial where the next owner is telling you, the new car owner, how to drive and maintain it as you drive it off the car lot.

 

[mikedodge]

The same going nowhere conversation revived after two years. Must have been a slow night lol