Temperature limitation 110.14C

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cppoly

Senior Member
Location
New York
Section 110.14(C)(1)(A) says:

"Termination provisions of equipment for circuits rated 100 amperes or less, or marked 14 AWG through 1 AWG conductors, shall be used only for one of the following..."

(1) Conductors rated 60 degree C, etc....

If the circuit is rated 100 A or less then OK it makes sense that you must use the 60 degree C column from the conductor ampacity table. But, what does this mean marked 14 AWG through 1 AWG conductors? #1 AWG is rated for 110 A in the 60 degree C column. My question is, what is the point at which you can switch over to the 75 degree amapcity column: #1 AWG or 1/0 AWG if the terminals are marked for 60 degree C? The wording is confusing.
 
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templdl

Senior Member
Location
Wisconsin
cppoly said:
Section 110.14(C)(1)(A) says:

"Termination provisions of equipment for circuits rated 100 amperes or less, or marked 14 AWG through 1 AWG conductors, shall be used only for one of the following..."

(1) Conductors rated 60 degree C, etc....


These are my thoughts:
If the circuit is rated 100 A or less then OK it makes sense that you must use the 60 degree C column from the conductor ampacity table. But, what does this mean marked 14 AWG through 1 AWG conductors? #1 AWG is rated for 110 A in the 60 degree C column. My question is, what is the point at which you can switch over to the 75 degree amapcity column: #1 AWG or 1/0 AWG if the terminals are marked for 60 degree C? The wording is confusing.
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These are my thoughts:
If the terminations are marked 60degC then you are locked in with the 60degC column and only are able to use the 75 and 90degC for deratings. 60degC wire was very common at one time as with the older NM nonmetalic wire. Then NMB came along but it still has to be allpied at 60degC up to 100a. The benifit of NMB is where you have to terminate it in a light fixter outlet. How many times have you removed a fixure wire with the old NM or even BX wire and the insulation falls appart when you even look at it.
Devices above 100A should have 75degC rated terminals and as such as long as the wire is rated 75degC and about you are allowed to use the 75degC column using the benifits that 90degC and sometimes higher rated wire brings to the party for derating purposes.
 
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cppoly

Senior Member
Location
New York
For a designer though, I won't know what the terminations are marked until after equipment is installed. It's unclear on when to switch over to the 75 degree C column.
 
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templdl

Senior Member
Location
Wisconsin
charlie b said:
I include in the project scope whatever time is needed to investigate existing conditions.
Click to expand...

Yup, as there is existing 60degC rated wire there has to be 60degC terminals. All newer equipment should have 75degC rated terminals. As soon as you confirm what the terminations are rated at which should not be a big issue then applying the rated cable should be a non issue.
 
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