[Jhellwig]

At work we get leviton model n7899 gfcis. I am trying to find the wire tempature rating but the information in the box doesn't have it nor does their website. The only tempature they mention in an operating range. I emailed their product support and they gave me the operating tempature range again. I also checked some other manufactures sites and none of them list a connection temp for any device.

What am I missing here? Why are they hiding this info? If I remember right if it doesn't list a tempature then you default to 60c. That makes life a pain.

 

[wildleg]

.... If I remember right if it doesn't list a tempature then you default to 60c. .....

I concur.

110.14 (1) Equipment Provisions. The determination of termination
provisions of equipment shall be based on 1l0.l4(C)(l)(a) or
(C)(1 )(b). Unless the equipment is listed and marked otherwise,
conductor ampacities used in determining equipment termination
provisions shall be based on Table 310.15(B)(l6) as
appropriately modified by 310.l5(B)(7).
(a) Termination provisions of equipment for circuits
rated 100 amperes or less, or marked for 14 AWG through 1
AWG conductors, shall be used only for one of the following:
(1) Conductors rated 60°C (l400P).
(2) Conductors with higher temperature ratings, provided the
ampacity of such conductors is determined based on the
60°C (140°F) ampacity of the conductor size used.
(3) Conductors with higher temperature ratings if the equipment
is listed and identified for use with such conductors.
(4) For motors marked with design letters B, C, or D, conductors
having an insulation rating of 75°C (l67°P) or
higher shall be permitted to be used, provided the ampacity
of such conductors does not exceed the 75°C
(l67°P) ampacity.

 

[FrunkSlammer]

In Canaduh if it doesn't list a temperature rating, it's 90c by default.

 

[wildleg]

In Canaduh if it doesn't list a temperature rating, it's 90c by default.

dats nuts

 

[FrunkSlammer]

Yeah but neither make a difference because 60c and 90c are still higher than 20A, which the breaker size for a 20A GFCI. I can't imagine your code is less than 20A for #[email protected]?

 

[Jhellwig]

Yeah but neither make a difference because 60c and 90c are still higher than 20A

Not any more. Now 12 is 20 amp at 60c. They changed the code. More than 3 current carrying at 20 amps at 60c means you have to have #10 now. That is what I am trying to get away from.

It is funny that first they ruin multi wire circuits and now they mess with the derating. More copper, bigger conduit, more labor and less money to do it with. Yeehaw

 

[FrunkSlammer]

Probably the meds I'm on, but what do you mean more than "3 current carrying at 20amps"?

 

[Jhellwig]

12 is rated for 20 amps at 60c now. 80 percent derate for 4-6 current carrying conductors means it is only good for 16 amps. So now you have to pull 10s instead where 12s were good before.

 

[AllWIRES]

If you're using thhn you would derate from the 90c column. Same with NM cable.

With the maximum amperage after derating being 20a

 

[FrunkSlammer]

Yeah don't derate the wire insulation because of the terminal connection temperature and then derate the wire insulation because of multiple wires. That doesn't make sense.

 

[AllWIRES]

110.14

(C) Temperature Limitations. The temperature rating associated with the ampacity of a conductor shall be selected and coordinated so as not to exceed the lowest temperature rating of any connected termination, conductor, or device. Conductors with temperature ratings higher than specified for terminations shall be permitted to be used for ampacity adjustment, correction, or both.

334.80 Ampacity.
The ampacity of Types NM, NMC, and NMS cable shall be determined in accordance with 310.15. The ampacity shall be in accordance with the 60°C (140°F) conductor temperature rating. The 90°C (194°F) rating shall be permitted to be used for ampacity derating purposes, provided the final derated ampacity does not exceed that for a 60°C (140°F) rated conductor. The ampacity of Types NM, NMC, and NMS cable installed in cable tray shall be determined in accordance with 392.11.

 

[Jhellwig]

So I guess I am not understanding 110.14(C). I thought you had to use whatever tempature was the lowest. For instance if the terminal is rated for 60c you had to start with the 60c column and then derate from there. Now that I keep re reading it it looks like you start the derating from whatever the wire is rated for regardless of what the terminal is rated for. What is the point of knowing the terminal tempature then? There must be some reason.

 

[AllWIRES]

So I guess I am not understanding 110.14(C). I thought you had to use whatever tempature was the lowest. For instance if the terminal is rated for 60c you had to start with the 60c column and then derate from there. Now that I keep re reading it it looks like you start the derating from whatever the wire is rated for regardless of what the terminal is rated for. What is the point of knowing the terminal tempature then? There must be some reason.

You derate based on the maximum temperature rating of the conductor but your final number can not exceed the temperature rating on the terminal you are using.

 

[Jhellwig]

Ok that makes sense. The more I got to thinking I knew I was worn I just didn't know why. Now I gotta convince the stubborn old guys at work that we don't need to pull 10 for 20 amp circuits.

I learned this 12 years ago in college. I just haven't had to deal with more than 3 current carrying conductors till now so I have forgot a lot.

 

[FrunkSlammer]

damn that would be a serious waste of money!!

 

[Jhellwig]

That is why I need to be able to explain this to them. I always thought it wasn't needed but I got confused when I tried to figure out why. We always pull more than one circuit in the conduit when we run outlets around here so this is getting to be a big issue.

So apparently I busted my butt yesterday pulling 9 #10s through 3/4 EMT for 4 20 amp circuits for nothing.

 

[AllWIRES]

That is why I need to be able to explain this to them. I always thought it wasn't needed but I got confused when I tried to figure out why. We always pull more than one circuit in the conduit when we run outlets around here so this is getting to be a big issue. So apparently I busted my butt yesterday pulling 9 #10s through 3/4 EMT for 4 20 amp circuits for nothing.

Be aware if you go over 9 conductors it will derate by 50%.

Table 310.15(B)(2)(a)

 

[Jhellwig]

8 current carrying and a ground.

 

[Jhellwig]

We are having this debate again and the guys I work with are having a hard time with 110.14(C). Is there a drawing that illustrates this somewhere.

 

[AllWIRES]

We are having this debate again and the guys I work with are having a hard time with 110.14(C). Is there a drawing that illustrates this somewhere.

I don't know how a drawing could explain it any better then it's written.