20a breaker protecting #8 wire

[hillbilly1]

I think the reasoning behind it is to allow the ocp to trip quicker on a short, if the resistance is high enough, the fault current would be lower, slowing down the trip time due to the inverse time delay characteristics of the breaker. If you have ever heard the conduits (tubing:lol rattle on a long run under a fault, that is partially what is causing it.

 

[mm11]

If you had a 20a breaker and circuit but the distance required # 8 wire due to VD would anything be wrong with doing that? I would think the breaker would need to be changed .. No? Thanks

<br><br>Look at 210.3-Rating. "Branch circuits recognized by this article shall be rated in accordance wiht the maximum permitted ampere rating or setting of the overcurrent device....Where conductors of high ampacity are used for any reason, the ampere rating or setting of the specified overcurrent device shall determine the circuit rating."<br><br>

 

[kbsparky]

Cetrainly you would agree that this is not the same as someone coming along in the future and changing circuit breakers to a larger size.

I certainly would not agree with this. It is the exact same thing: The Code is playing the "what if" scenario when they require something that is not needed for the present installation to function properly, based on a whim that someone might change up something in the future.

 

[hillbilly1]

It sure don't stop them from slapping a 30 amp breaker in with a #14 wire! Changed out a panel in a retail space, found all #14 wire, with all 30 amp single pole and double pole breakers which was signature of a certain local contractor. (Finally lost his license after 50 years and a customer of his turning him into the state) Nearly all of the Romex was brown instead of white! (And it was only a three year old install)

 

[stickboy1375]

It sure don't stop them from slapping a 30 amp breaker in with a #14 wire! Changed out a panel in a retail space, found all #14 wire, with all 30 amp single pole and double pole breakers which was signature of a certain local contractor. (Finally lost his license after 50 years and a customer of his turning him into the state) Nearly all of the Romex was brown instead of white! (And it was only a three year old install)

Did anyone question his actions on why he thought it was okay?

 

[hillbilly1]

Did anyone question his actions on why he thought it was okay?

He had been wiring houses back when they just had a small fuse panels, 30 amp Edison base fuses were the norm. He had no formal electrical education, he just knew that's the way he always done it, and didn't see anything wrong with it. Georgia did not have a state electrical license until the early 80's, so once they started issuing license's, they grandfathered everybody in that could prove they had been in the trade a couple of years, and have a building contractor sign for them. No test or other means to prove competency.

 

[stickboy1375]

He had been wiring houses back when they just had a small fuse panels, 30 amp Edison base fuses were the norm. He had no formal electrical education, he just knew that's the way he always done it, and didn't see anything wrong with it. Georgia did not have a state electrical license until the early 80's, so once they started issuing license's, they grandfathered everybody in that could prove they had been in the trade a couple of years, and have a building contractor sign for them. No test or other means to prove competency.

Wow... crazy....

 

[fmtjfw]

I not sure we let our grandfather use the TV remote, let alone pick wire sizes

I not sure we let our grandfather use the TV remote, let alone pick wire sizes

I worked with a grandfathered master electrician who believed that neutrals were 2 sizes below hot and grounds 2 sizes below neutrals (30 Amp ciircuit = #10 H, #12 N, #14 G). I was pulling 3 #10s for a circuit and he cut the wires with his dikes and tried to start a fight.:rant:

I went back later and fixed later:roll:.

 

[spark master]

Logically, I agree with upsizing the ground, when upsizing the hots. in event of a short, you don't want a voltage drop across the ground. you want as low resistance as possible on the return path to earth.

 

[ActionDave]

Logically, I agree with upsizing the ground, when upsizing the hots. in event of a short, you don't want a voltage drop across the ground. you want as low resistance as possible on the return path to earth.

Logically, do you agree with downsizing the equipment ground if you use a larger overcurrent device?

 

[Alwayslearningelec]

Yes.

Why can't use NM cable.... Isnt there a ground

 

[Alwayslearningelec]

This has been discussed here a lot. No clear reason has ever been given.

Can't the EMT be used as the ground no matter what? So why would a seParate ground ever need to be Pulled? Thanks

 

[fmtjfw]

Except for certain cases EMT can be used for "the" ground conductor. But it has a splice every 10 feet or less. Just as I would avoid gratuitous splices every 10 feet or so in a wire conductor, I avoid using the raceway as the sole means of grounding.

I accord the grounding wire at least the same "respect" as the neutral and hot. Actually greater respect, in that a bad grounding connection may not be apparent until it is needed. A bad hot or neutral is a lot more apparent.

 

[fmtjfw]

In terms of upsizing the grounding wire when upsizing the current carrying wires, ignoring the fact that the NEC requires it for a moment, you can apply two theories:

1) The upsizing is to reduce voltage drop in the grounding conductor under fault conditions, to reduce touch shock probabilities and reduce ground fault clearing times. In this case you are for upsizing.

2) The size of the grounding conductor is chosen so it it does not melt and disappear during fault conditions. In this case its size would be based on the rating of the OCPD, and you are against upsizing.

 

[kbsparky]

In terms of upsizing the grounding wire when upsizing the current carrying wires, ignoring the fact that the NEC requires it for a moment, you can apply two theories:

1) The upsizing is to reduce voltage drop in the grounding conductor under fault conditions, to reduce touch shock probabilities and reduce ground fault clearing times. In this case you are for upsizing.

2) The size of the grounding conductor is chosen so it it does not melt and disappear during fault conditions. In this case its size would be based on the rating of the OCPD, and you are against upsizing.

Explain this scenario to me then:

Using a #6 wire fed from a 60 Amp breaker only requires a #10 EGC.

Take that SAME #6 wire, and feed it from a 20 Amp breaker, now the EGC is required to be a #6!

How is the ground wire any safer being a #10 on a 60 Amp circuit?

 

[stickboy1375]

Explain this scenario to me then:

Using a #6 wire fed from a 60 Amp breaker only requires a #10 EGC.

Take that SAME #6 wire, and feed it from a 20 Amp breaker, now the EGC is required to be a #6!

How is the ground wire any safer being a #10 on a 60 Amp circuit?

Im no expert on this, BUT... if you increase wire size to reduce voltage drop, don't you think the same effects occur on the grounding conductor as well? Without increasing the grounding conductor, during a fault, you incur voltage drop on the grounding conductor. (Yes or No?)

 

[kbsparky]

YOU did not answer my question.

How is it safer for a 60 Amp circuit to only require a #10 ground VS a 20 Amp circuit with a #6 ground?



Your logic defies me here ....

 

[stickboy1375]

YOU did not answer my question.

How is it safer for a 60 Amp circuit to only require a #10 ground VS a 20 Amp circuit with a #6 ground?



Your logic defies me here ....

I have no idea... :ashamed1:

 

[ActionDave]

Can't the EMT be used as the ground no matter what?

Sure can.

So why would a seParate ground ever need to be Pulled? Thanks

Because job specs call for it, or it gives the person installing one a sense of quality in their installation.

I rarely pull a green unless I'm told to. The EMT is a better equipment ground than any wire you could stuff in it.

 

[newservice]

i always put a neutral in every switch box. always have. but that's just me.

Ummmm, what about a simple switch leg? Cant we do those any more? Gonna make life pretty hard if that's true