Termination Temperature Rating & Upsizing Ground

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PowerEE

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1. Are there any pieces of commercial or industrial grade equipment that are only rated 60* C?

2. This question is related to code 110.14(C) and code 250.122(B). Say for a 100A breaker (marked 60/75), I design the wire size to be #1 AWG (110A) from the 60*C column. The specifications state to use THWN wire, so the contractor installs #1 AWG (130A) rated 75*C. Since the minimum wire ampacity should be #3 AWG for 75*C, shouldn't this require the ground to be upsized per 250.122(B)?

This question is in regards to commercial and industrial only. My concern is applying code 110.14(C) for all pieces of equipment 100A and below, especially for new construction. For a renovation project, I might run into electrical equipment that is not marked with a termination temperature rating. For new construction, how often do you see a piece of equipment that is not marked with a termination temperature rating?
 
PowerEE said:
1. Are there any pieces of commercial or industrial grade equipment that are only rated 60* C?

2. This question is related to code 110.14(C) and code 250.122(B). Say for a 100A breaker (marked 60/75), I design the wire size to be #1 AWG (110A) from the 60*C column. The specifications state to use THWN wire, so the contractor installs #1 AWG (130A) rated 75*C. Since the minimum wire ampacity should be #3 AWG for 75*C, shouldn't this require the ground to be upsized per 250.122(B)?

This question is in regards to commercial and industrial only. My concern is applying code 110.14(C) for all pieces of equipment 100A and below, especially for new construction. For a renovation project, I might run into electrical equipment that is not marked with a termination temperature rating. For new construction, how often do you see a piece of equipment that is not marked with a termination temperature rating?
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@PowerEE

In regards to commercial and industrial, the application of 110.14(C) applies to all applications, including residential, just wanted to clarify that before I went on. You can use a higher temperature rated conductor [110.14(C)(2)] and still maintain the ampacity value of the 60 degree column. Also most all equipment will be listed and identified for use with 60/75, so if the device is listed and identified for 75 then it would not matter because 110.14(C)(3) covers for this.

Remembers this is very common, for example most THHN is 90 degree rated insulation but is used on 75 degree or even 60 degree terminations all the time as long as we keep in mind the ampacity limitation of the terminations you are dealing with which is the main charging scope of 110.14- Electrical Connections.

As for 250.122(B) I would not see this as being a trigger for 250.122(B) requiring an increase in EGC size.

Those are my thoughts on the subject. Hope it was helpful.
 
PowerEE said:
2. This question is related to code 110.14(C) and code 250.122(B). Say for a 100A breaker (marked 60/75), I design the wire size to be #1 AWG (110A) from the 60*C column. The specifications state to use THWN wire, so the contractor installs #1 AWG (130A) rated 75*C. Since the minimum wire ampacity should be #3 AWG for 75*C, shouldn't this require the ground to be upsized per 250.122(B)?
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IMO the EGC needs to be increased in size since, as you've stated, the #3 AWG condcutors would be compliant for a 100 amp OCPD.
 
I don't see any reason to upsize the ground. The #1 THWN with an ampacity of 110 meets the requirements of 110.14(C)(1)(a)(2).
 
infinity said:
IMO the EGC needs to be increased in size since, as you've stated, the #3 AWG condcutors would be compliant for a 100 amp OCPD.
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Section 250.122(B) says where the ungrounded conductor was increased in size, he did not increase the size as he is still using the 60 degree column, just used a conductor with a different (higher insulation rating) insulation rating. The conductor is still a 1 AWG.

Thats my opinion....FWIW

Or be could use the raceway(compliant with 250.118) and say Poo-Poo on you code dudes.......and then 250.122(B) wont apply.

Edited: BTW...what is a condcutor?..is that a new type of EGC?...:angel:
 
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MasterTheNEC said:
Section 250.122(B) says where the ungrounded conductor was increased in size, he did not increase the size as he is still using the 60 degree column, just used a conductor with a different (higher insulation rating) insulation rating. The conductor is still a 1 AWG.

Thats my opinion....FWIW

Or be could use the raceway(compliant with 250.118) and say Poo-Poo on you code dudes.......and then 250.122(B) wont apply.

Edited: BTW...what is a condcutor?..is that a new type of EGC?...:angel:
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So the #3 THWN with 75? C terminations and a 100 amp OCPD is a violation?
 
david luchini said:
The terminal is suitable for use with 60deg conductors (at the 60deg ampacity) and 75deg conductors (at the 75 deg ampacity.)
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Okay, that covers the obvious... so I should have alluded to within the context of the OP.

IOW, with a 60/75 rating are we required to use 75 column with 75 and 90 conductors ... or can we use the 60 column for minimum size???
 
Smart $ said:
Okay, that covers the obvious... so I should have alluded to within the context of the OP.

IOW, with a 60/75 rating are we required to use 75 column with 75 and 90 conductors ... or can we use the 60 column for minimum size???
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Ummm, this gets done all the time with NM-B cable...correct?

I think if you use the 60 degree column on jobs where the use of the 75 degree column was permitted that chances are you would be buying larger wire than you would really need would make the manufacturers of the wire happy but is a design choice. The issue here is really the protection of the insulation at hand and if you tend to load the wire at the 60 degree column values you are keeping the heat rise below the temperature limits of the conductors insulation...just being overly cautious if using a THWN.

As for someone elses post (sorry I can't remember now) the question was, or wait it was infinity, sorry brain drain this morning. The question was "So the #3 THWN with 75? C terminations and a 100 amp OCPD is a violation?"

Well I see the conductor being installed was a 1 AWG and not a 3 AWG. I see no problem (as I know where you are going..in 110.14(C)(1)(a) but again i see 110.14(C)(1)(a)(2) applying.
 
Smart $ said:
Okay, that covers the obvious... so I should have alluded to within the context of the OP.

IOW, with a 60/75 rating are we required to use 75 column with 75 and 90 conductors ... or can we use the 60 column for minimum size???
Click to expand...

You can use the 60 column with 60deg, 75deg or 90deg conductors.
 
MasterTheNEC said:
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Well I see the conductor being installed was a 1 AWG and not a 3 AWG. I see no problem (as I know where you are going..in 110.14(C)(1)(a) but again i see 110.14(C)(1)(a)(2) applying.
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Yes... but 110.14(C)(1)(a)(3) is also applicable... and that's the dilemma. Who gets to decide which when it comes to determining whether the #1 is compliant with or in violation of 250.122(B)...??? The designer is going to opt for (2) while the AHJ may feel (3) is appropriate and enforceable.
 
Smart $ said:
Yes... but 110.14(C)(1)(a)(3) is also applicable... and that's the dilemma. Who gets to decide which when it comes to determining whether the #1 is compliant with or in violation of 250.122(B)...??? The designer is going to opt for (2) while the AHJ may feel (3) is appropriate and enforceable.
Click to expand...

And basically I believe that most can convince the EI that they are saying roughly the same thing, that you can use a higher temperature rated insulation (much like we do with NM-B) and still meet the 60 degree. To be honest with you I find this a little "over anal-ising" something that is just not really there in THIS example. Might apply in other examples but in this example I would not tell the contractor to upsize anything....

But as we tend to say here....we can agree to disagree...we will let the games begin when the contractor meets the inspector and let them hash it out. Much like the handbook, we are all full of interpretations and i'm set on mine...;)
 
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