# Wire size and type limiting current



## HackWork (Oct 2, 2009)

So here is an interesting one. Recently an inspector said that I did something that was definitely against code, but he passed it anyway so I didn't push for his reasoning.

I replaced an old panel with a new one. The existing 50A feed for the range was #6 copper romex. I had to extend the 2 hot conductors with a short pigtail to reach the breakers, I used #8 THWN.

As we all know, #8 THWN is perfectly fine for 50A. But when that same size copper conductor is inside of romex, it is now only good for 40A for whatever reason.

The pigtail that I use was real THWN, labelled as such, and was not part of the romex assembly.

Code?


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## splatz (May 23, 2015)

Would it be equivalent to transitioning from one wiring method to another, or is a pigtail not really a wiring method? 



HackWork said:


> So here is an interesting one. Recently an inspector said that I did something that was definitely against code, but he passed it anyway so I didn't push for his reasoning.
> I replaced an old panel with a new one. The existing 50A feed for the range was #6 copper romex. I had to extend the 2 hot conductors with a short pigtail to reach the breakers, I used #8 THWN.
> 
> As we all know, #8 THWN is perfectly fine for 50A. But when that same size copper conductor is inside of romex, it is now only good for 40A for whatever reason.
> ...


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## Roger123 (Sep 23, 2007)

In other words, you extended a 50 amp circuit that was installed with NM conductors in a residential dwelling.


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## HackWork (Oct 2, 2009)

Roger123 said:


> In other words, you extended a 50 amp circuit that was installed with NM conductors in a residential dwelling.


Good or no?


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## Roger123 (Sep 23, 2007)

HackWork said:


> Good or no?


:smile:

I say maybe a violation of 334.80


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## HackWork (Oct 2, 2009)

Roger123 said:


> :smile:
> 
> I say maybe a violation of 334.80


Disqualified for not posting the code.


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## CoolWill (Jan 5, 2019)

As long as the splice was in a legal location, I say good.


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## Switched (Dec 23, 2012)

CoolWill said:


> As long as the splice was in a legal location, I say good.


I agree. I can't find where/how that would be a violation. He didn't cite a code?


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## Cow (Jan 16, 2008)

It is not a code violation despite what the inspector may think.

Each of the two wiring methods you were dealing with, Romex and THHN, are rated 50 amps, which you know.

If everyone can agree on that, then the inspectors argument boils down to the fact you joined them together with a splice.

When did splices become violations?

On a different note, we are having a similar struggle with one inspector. We are working in a different area than usual on some larger projects and are dealing with an inspector we haven't dealt with before. We've had to spend a fair amount of time educating the inspector, who appears to be looking for reasons to fail us, on what is actually in the code book. 

It's tough when you haven't had an opportunity to establish a good working relationship with your inspector(s).


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## HackWork (Oct 2, 2009)

Switched said:


> I agree. I can't find where/how that would be a violation. He didn't cite a code?


No because he passed it, as if he was doing me a favor.

I do agree that on the surface it seems odd. But once you put some thought into it, it’s no different than any other time we transition. For example, for a 60A charger I will often run #6 Romax through a basement into a box in the garage, then run conduit with #6 around the garage to the charger.


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## HackWork (Oct 2, 2009)

mistake.


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## Bird dog (Oct 27, 2015)

Are all your terminations rated for 75 degrees? T310.15(B)(16) shows THWN in the 75 degree column. Also, The temperature limitations are in 110.14(C)(1).


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## HackWork (Oct 2, 2009)

Bird dog said:


> Are all your terminations rated for 75 degrees? T310.15(B)(16) shows THWN in the 75 degree column. Also, The temperature limitations are in 110.14(C)(1).


It’s a new residential panel.


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## macmikeman (Jan 23, 2007)

It's perfectly fine in the location you are describing. And on a secondary note- Although not acceptable to the NEC, the practice here was to run #6-3 alum see cable for range outlets for decades of my time as an electrician, all the while passing inspections with no problems nor questioning by any inspectors. Right up till around the year 2011 or so when they started following Mike Holt like a guru. 

My understanding is that the code book changed the temperature values from 75 deg column to 60 deg column for the types of nm cables and set cables due to *Canadians *complaining that the two countries had different values for those same gauges of conductor insulations.


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## HackWork (Oct 2, 2009)

I still use #6 AL SER cable for 50A. 

Wasn’t the issue if it was in a certain amount of thermal insulation? I don’t remember because I didn’t pay any attention to the stupid code change LOL.


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## macmikeman (Jan 23, 2007)

HackWork said:


> I still use #6 AL SER cable for 50A.
> 
> Wasn’t the issue if it was in a certain amount of thermal insulation? I don’t remember because I didn’t pay any attention to the stupid code change LOL.


Could have been due to insulation, but I remember watching a Holt video when Mike explained the Canadians(CMP'S) were fussing because USA and Canada had different ampacity values for the same cables . So according to Mike, big brother bent to please little brother.......... :vs_mad:


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## emtnut (Mar 1, 2015)

macmikeman said:


> Could have been due to insulation, but I remember watching a Holt video when Mike explained the Canadians(CMP'S) were fussing because USA and Canada had different ampacity values for the same cables . So according to Mike, big brother bent to please little brother.......... :vs_mad:


Cute story Bro , but #8 Loomex is good for 50A up here :biggrin:


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## dronai (Apr 11, 2011)

emtnut said:


> Cute story Bro , but #8 Loomex is good for 50A up here :biggrin:


Loomex ? did you guys go and change the name of romex to be different ?


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## Bird dog (Oct 27, 2015)

emtnut said:


> Cute story Bro , but #8 Loomex is good for 50A up here :biggrin:


Tin hat Mac strikes again. :biggrin:


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## Kevin (Feb 14, 2017)

HackWork said:


> No because he passed it, as if he was doing me a favor.


He probably passes it because he couldn't remember if it's against code.

Sent from my new phone. Autocorrect may have changed stuff.


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## HackWork (Oct 2, 2009)

Kevin_Essiambre said:


> He probably passes it because he couldn't remember if it's against code.


He was very sure it was against code.

His line of thinking was that #8 romex can't handle 50A. That is why they used #6. So he thinks extending that romex would also require #6.

I agree that it seems odd. But it's code compliant.


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## HackWork (Oct 2, 2009)

Roger123 said:


> :smile:
> 
> I say maybe a violation of 334.80


Can you tell me which part??



> 334.80 Ampacity. The ampacity of Types NM, NMC, and NMS
> cable shall be determined in accordance with 310.15. The
> allowable ampacity shall not exceed that of a 60°C (140°F)
> rated conductor. The 90°C (194°F) rating shall be permitted to
> ...


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## Bird dog (Oct 27, 2015)

HackWork said:


> He was very sure it was against code.
> 
> His line of thinking was that #8 romex can't handle 50A. That is why they used #6. So he thinks extending that romex would also require #6.
> 
> I agree that it seems odd. But it's code compliant.


Did he ask you for your reasoning to do it?


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## emtnut (Mar 1, 2015)

dronai said:


> Loomex ? did you guys go and change the name of romex to be different ?



Loomex is romex, but not stuffed with paper :biggrin:


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## HackWork (Oct 2, 2009)

Bird dog said:


> Did he ask you for your reasoning to do it?


Nope. He didn't care


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## HackWork (Oct 2, 2009)

emtnut said:


> Loomex is romex, but not stuffed with paper :biggrin:


We need to come together to make a better product. I want a romex type cable with no paper that could be used in a damp location, and insulated ground for safety.


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## flyboy (Jun 13, 2011)

CoolWill said:


> As long as the splice was in a legal location, I say good.


Does that mean if it was in a brothel in Santee, S.C. it would be illegal?


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## emtnut (Mar 1, 2015)

flyboy said:


> Does that mean if it was in a brothel in Santee, S.C. it would be illegal?



Which states are brothels legal in ?? .... Asking for a friend :biggrin:


OK 99, I asked for you :vs_laugh:


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## emtnut (Mar 1, 2015)

HackWork said:


> We need to come together to make a better product. I want a romex type cable with no paper that could be used in a damp location, and insulated ground for safety.



And have thhn/thwn stamped on the conductors, since that's what they are anyways.



Back to the range, is it higher than 12kW ?


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## CoolWill (Jan 5, 2019)

flyboy said:


> Does that mean if it was in a brothel in Santee, S.C. it would be illegal?


I can't find "brothel" in Article 100:sad:


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## HackWork (Oct 2, 2009)

emtnut said:


> And have thhn/thwn stamped on the conductors, since that's what they are anyways.
> 
> 
> 
> Back to the range, is it higher than 12kW ?


No idea, I was only there to change the panel. I never even went in the kitchen.


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## CoolWill (Jan 5, 2019)

emtnut said:


> Which states are brothels legal in ?? .... Asking for a friend :biggrin:
> 
> 
> OK 99, I asked for you :vs_laugh:


If it's for 99cents, it will be a bathhouse you're looking for.


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## HackWork (Oct 2, 2009)

CoolWill said:


> If it's for 99cents, it will be a bathhouse you're looking for.


Brutal.

That could only have been a worse burn if you added the year 1985 to it.


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## telsa (May 22, 2015)

No, it was because the splice was in Free Air.

That'll bail you out every time.


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## CoolWill (Jan 5, 2019)

HackWork said:


> Brutal.
> 
> That could only have been a worse burn if you added the year 1985 to it.


Some year of the past called and said that the thing you said is theirs and they'd like it back. BURN!!!


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## joe-nwt (Mar 28, 2019)

macmikeman said:


> Could have been due to insulation, but I remember watching a Holt video when Mike explained the Canadians(CMP'S) were fussing because USA and Canada had different ampacity values for the same cables . So according to Mike, big brother bent to please little brother.......... :vs_mad:


Come on.....does that seem even remotely realistic to you?


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## CoolWill (Jan 5, 2019)

joe-nwt said:


> Come on.....does that seem even remotely realistic to you?


Sorta. I was talking with a Southwire engineer a couple years ago and he mentioned something about NEC and CEC ampacities and an effort to harmonize them. Don't remember the details.


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## joe-nwt (Mar 28, 2019)

CoolWill said:


> Sorta. I was talking with a Southwire engineer a couple years ago and he mentioned something about NEC and CEC ampacities and an effort to harmonize them. Don't remember the details.


Typically that's engineer speak for CEC will do what NEC tells them. It's mandatory for all our politicians and regulatory bodies to have their spine removed at indoctrination so I somehow doubt anything we say is worth a pinch of **** $hit.


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## Galt (Sep 11, 2013)

No doubt it will burst into flames.


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## emtnut (Mar 1, 2015)

CoolWill said:


> Sorta. I was talking with a Southwire engineer a couple years ago and he mentioned something about NEC and CEC ampacities and an effort to harmonize them. Don't remember the details.



I've read about it in a few articles. They are trying to harmonize the 2 codes.
It would be a benefit to us, because we source many items from the US.

Would be nice to have plastic boxes without ground bar ... maybe they would come down in price ! (They're ridiculously expensive up here)



But you guys will have to call it Loomex ... we're not budging on that one :biggrin:


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## Kevin (Feb 14, 2017)

emtnut said:


> I've read about it in a few articles. They are trying to harmonize the 2 codes.
> It would be a benefit to us, because we source many items from the US.
> 
> Would be nice to have plastic boxes without ground bar ... maybe they would come down in price ! (They're ridiculously expensive up here)
> ...


I would love for them to ship us 14/4 and 14/2/2 cables up here... maybe in #12 as well.

Sent from my new phone. Autocorrect may have changed stuff.


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## Cow (Jan 16, 2008)

Kevin_Essiambre said:


> I would love for them to ship us 14/4 and 14/2/2 cables up here... maybe in #12 as well.
> 
> Sent from my new phone. Autocorrect may have changed stuff.


Maybe we can trade. 

You just have to get teck listed for us to use down here, so we can wire everything from toasters to industrial kilns to igloos with it. Like you guys up north...


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## CoolWill (Jan 5, 2019)

emtnut said:


> Would be nice to have plastic boxes without ground bar ... maybe they would come down in price ! (They're ridiculously expensive up here)


That's crazy talk. We have it on good authority that switches and receptacles would be impossible to bond without that ground strap. Are you trying to kill yourself!?




> But you guys will have to call it Loomex ... we're not budging on that one :biggrin:


I'll buy a lantern and disconnect my service before I call it loomex:vs_mad:


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## MTW (Aug 28, 2013)

What does a Canadian plastic box with ground strap cost versus a similar metal device box?


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## Mulder (Sep 11, 2010)

Cow said:


> Maybe we can trade.
> 
> You just have to get teck listed for us to use down here, so we can wire everything from toasters to industrial kilns to igloos with it. Like you guys up north...


"Tek" is listed in the US and can be used here. It just is not called Tek (or whatever) it is available as PVC coated MC cable. It has become more popular around here. Look at 330.10(A)(11)


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## joe-nwt (Mar 28, 2019)

MTW said:


> What does a Canadian plastic box with ground strap cost versus a similar metal device box?


Mega bazzilion dollars more. Many a contractor have gone belly up with the added cost of these cumbersome contraptions and their installation.

Apparently.


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## Kevin (Feb 14, 2017)

Mulder said:


> "Tek" is listed in the US and can be used here. It just is not called Tek (or whatever) it is available as PVC coated MC cable. It has become more popular around here. Look at 330.10(A)(11)


False. You have what we call ACWU. It only has a waterproof outer coating. TECK90 has an inner AND outer waterproof layer. See photos. 

First one is PVC jacketed MC cable.
Second is TECK90.
Third is they layer breakdown of TECK90.









Sent from my new phone. Autocorrect may have changed stuff.


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## Kevin (Feb 14, 2017)

Cow said:


> Maybe we can trade.
> 
> 
> 
> You just have to get teck listed for us to use down here, so we can wire everything from toasters to industrial kilns to igloos with it. Like you guys up north...


Sounds like a deal to me.

Sent from my new phone. Autocorrect may have changed stuff.


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## Easy (Oct 18, 2017)

6 AWG NM is good for 55 AMPS on the chart I looked at. #8 THHN is also good for 50 amps at 75 deg. C. When you say “romex” you are talking about NM cable? It’s rated at 55 amps and falls in the 60 deg. C. column of the ampacity chart. Is this an accurate statement?


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## HackWork (Oct 2, 2009)

Easy said:


> When you say “romex” you are talking about NM cable?


 :surprise:



> It’s rated at 55 amps and falls in the 60 deg. C. column of the ampacity chart. Is this an accurate statement?


I don't know what you are saying here. The 60 degree column of #8 is 40A, not 55A.


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## Easy (Oct 18, 2017)

No not #8 .... #6 NM cable is rated at 55 AMPs .... @ 60 Deg. C 
#8 copper THHN is rated at 50 amps @ 75 Deg. C 
Therefor the #6 NM cable would have a higher ampacity ratting than the #8 THHN.. Just saying ...


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## HackWork (Oct 2, 2009)

Easy said:


> No not #8 .... #6 NM cable is rated at 55 AMPs ....


I'm not sure where #6 comes into this.


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## Easy (Oct 18, 2017)

You said "I replaced an old panel with a new one. The existing 50A feed for the range was #6 copper romex." What you did is fine as far as I am concerned. I am just confused on the temperature ratings of the wire as it applies to code in this situation.


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## HackWork (Oct 2, 2009)

Easy said:


> You said "I replaced an old panel with a new one. The existing 50A feed for the range was #6 copper romex." What you did is fine as far as I am concerned. I am just confused on the temperature ratings of the wire as it applies to code.


The question is about the piece of #8 that I used to extend the conductor. That is what the inspector said was against code.


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## Easy (Oct 18, 2017)

I think if you would have used #6 thhn that would have been a violation. By using # 8 thhn (rated at 50 amps) your max OCPD would be a 50 amps and if you put in #6 some knuckle head might up-size the breaker at a later date. You did good in my opinion.


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## HackWork (Oct 2, 2009)

Easy said:


> I think if you would have used #6 thhn that would have been a violation. By using # 8 thhn (rated at 50 amps) your max OCPD would be a 50 amps and if you put in #6 some knuckle head might up-size the breaker at a later date. You did good in my opinion.


I disagree with it being a violation to use #6 in my situation. Which code do you think it violates? 

FWIW, I use #12 to extend both 20A and 15A circuit conductors when replacing a panel. It's easier to bring in 1 size wire to do both. That would be against code as well if what you said is true.


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## Easy (Oct 18, 2017)

Under normal conditions I would not transition from 12 gage in a panel to 14 gage as my branch circuit. For voltage drop I would up-size. So I guess it's a mute point because as an electrician we need to look at the entire circuit before up-sizing the OCPD.


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## R777V (May 16, 2016)

I would have gone along with it as long as you weren’t “pig tailing” it inside the panel. Although I’m also not a fan of scaling down conductors even if the ampacity was sufficient. You couldn’t afford the cost of using #6?


Sent from my iPhone using Tapatalk


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## HackWork (Oct 2, 2009)

R777V said:


> I would have gone along with it as long as you weren’t “pig tailing” it inside the panel.


 I don't understand what you mean by "pig tailing". That is what I did, but we might be using that term differently.



> Although I’m also not a fan of scaling down conductors even if the ampacity was sufficient.


 The only person I am out to make happy is the customer. We are not uspposed to make the inspector happy by doing what he is a fan of, we are supposed to do what is code compliant. 



> You couldn’t afford the cost of using #6?


 Who said that I couldn't afford it? There are lots of things I can afford but do not waste money on. The right size piece of #8 was handy, so I used it.


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## MotoGP1199 (Aug 11, 2014)

-Splicing is allowed in panels
-#8 is suffecient
-Pigtailing usually is used to describe using wire nuts from one branch circuit and splitting it off to a device and continuing the circuit to the next device. What he did I would just call splicing.

I have down sized wires many many times. A lot of times someone over sizes wires to a motor based off of the circuit breaker size which is 200% or 250% times the motor FLA. If I do work on that circuit and install a Drive or new whip to the motor I will size it properly to 125% of FLA and not waste money. NO reason to oversize wire larger than needed based off of load, and de-rating factors.


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## HackWork (Oct 2, 2009)

MotoGP1199 said:


> -Splicing is allowed in panels
> -#8 is suffecient
> -Pigtailing usually is used to describe using wire nuts from one branch circuit and splitting it off to a device and continuing the circuit to the next device. What he did I would just call splicing.
> 
> I have down sized wires many many times. A lot of times someone over sizes wires to a motor based off of the circuit breaker size which is 200% or 250% times the motor FLA. If I do work on that circuit and install a Drive or new whip to the motor I will size it properly to 125% of FLA and not waste money. NO reason to oversize wire larger than needed based off of load, and de-rating factors.


Yeah, I figured the little piece of wire is called a pigtail. 

I could have used a 3M blue/gray wirenut to make this connection, but I used an aluminum barrel splice reducer instead.


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## R777V (May 16, 2016)

They aren’t keen in Chicago with splicing inside a panel, especially non residential, it might be code compliant but like you said make the inspector happy. That’s the bottom line, also the other golden rule “it was on the truck”. So use what you have at hand. More my own preference than anything else.


Sent from my iPhone using Tapatalk


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## Willie B (Jan 31, 2020)

Terminal temp rating at each end. Is it 75 Degree C?


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## CoolWill (Jan 5, 2019)

Willie B said:


> Terminal temp rating at each end. Is it 75 Degree C?


At least with the new breaker, yes. The other end, well, the inspector probably didnt go look, so it wouldn't have any impact.


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## HackWork (Oct 2, 2009)

CoolWill said:


> At least with the new breaker, yes. The other end, well, the inspector probably didnt go look, so it wouldn't have any impact.


The other end was 6 inches away inside of the panel, a set screw spice reducer.


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## macmikeman (Jan 23, 2007)

emtnut said:


> Cute story Bro , but #8 Loomex is good for 50A up here :biggrin:


Yea, and your ambient is 0 centigrade..... 


I know what I watched. I didn't say it, I repeated it. From about twenty years ago , which is when we started having to attend CEU classes that showed Mike Holt Code changes movies back then.


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## Easy (Oct 18, 2017)

CoolWill said:


> At least with the new breaker, yes. The other end, well, the inspector probably didnt go look, so it wouldn't have any impact.


I think you are talking about the other end being the range receptacle and those lugs would probably be 75 deg. C, but they could also be 60. Who knows. I'm just glad that Hack didn't use big blue wire nuts to splice inside the panel.


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## CoolWill (Jan 5, 2019)

HackWork said:


> The other end was 6 inches away inside of the panel, a set screw spice reducer.





Easy said:


> I think you are talking about the other end being the range receptacle and those lugs would probably be 75 deg. C, but they could also be 60. Who knows. I'm just glad that Hack didn't use big blue wire nuts to splice inside the panel.


Yes, I'm talking about the range receptacle end being uninspected.


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## HackWork (Oct 2, 2009)

The termination on the range receptacle wouldn’t matter.


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## Easy (Oct 18, 2017)

HackWork said:


> The termination on the range receptacle wouldn’t matter.


Yes true .. conductor already at 60 so it's as low as it can go.I slip tracks some times. It's my OCD kicking in.


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## Easy (Oct 18, 2017)

The important thing is you did not have to pull the range out, or pull out the plug for inspection. You and Coolwill really know code and make learning very enjoyable.


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## CoolWill (Jan 5, 2019)

HackWork said:


> The termination on the range receptacle wouldn’t matter.


I know. It read to me like Willie B was saying it did.


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