Safety problem with feeders and branch circuits in the same wireway.

[avargasm]

That only applies if the equipment isn’t rated for 75 degree termination. Ask Mike Holt

Well, that's the equipment that I'm going to use. I'm keeping parts of a system already installed and the breakers are 60°.

Anyways, I think that you went somewhat off-topic. Thank you for your time and knowledge.

 

[Patpowers]

Ok , that is settled. The branch circuit can share the raceway with the feeders, we do it all the time in industrial and even sometimes in residential. We may have the feeders coming in to our sub panel and we leave out the same conduit with a protected branch circuit to supply outdoor outlets, and / lights

 

[don_resqcapt19]

Well, that's the equipment that I'm going to use. I'm keeping parts of a system already installed and the breakers are 60°.

Anyways, I think that you went somewhat off-topic. Thank you for your time and knowledge.

They must be decades old then, as breakers have had 75°C terminations for a long time.

However it is your design, and you your plan exceeds the requirements of the NEC, so it is not wrong.

 

[tom baker]

It would be very unusual to have a 1/0 on 100 amp OCPD, and it would not fit in the 100 amp lug

I was wrong and I checked a Sq D QOP 2/100 plug on a 2/0 will fit but thats a big wire for a plug on breaker, when a #3 is rated 100 amps at 75 deg C

 

[avargasm]

I was wrong and I checked a Sq D QOP 2/100 plug on a 2/0 will fit but thats a big wire for a plug on breaker, when a #3 is rated 100 amps at 75 deg C

Thanks. I am using 60° terminals. So, the next wire is a 1 AWG, but odd numbers are hardly found in the market or not built at all. So, the real next number is 1/0.

 

[tom baker]

Equipment 100A or less is usually rated 60° on terminals. It's also on Mike Holt's books.

Maybe this molded breaker is 75° because it's industrial grade. And remember: that number in the table is BEFORE derating.

 

[avargasm]

That's not my building in the photo. It was just an example of a 100A breaker with a 1/0 wire to show you that your statement was wrong.

 

[tom baker]

Equipment 100A or less is rated 60° on terminals. It's also on Mike Holt's books.

I have been an electrician for 40+ years retired as a master electrician, I have only seen one device with 60 Deg C terminals, an old dryer plug installed in 1940. Myself and nearly all others size wire from the 75 Deg C column, smaller wire, less copper, smaller conduit..the larger wire sizes from the 60 deg C column can certainly be used
I have know Mike Holt since 1996 and here is what he has to say

 

[tom baker]

That's not my building in the photo. It was just an example of a 100A breaker with a 1/0 wire to show you that your statement was wrong.

Yes I was incorrect but the wire could of been a #3

 

[avargasm]

I have been an electrician for 40+ years retired as a master electrician, I have only seen one device with 60 Deg C terminals, an old dryer plug installed in 1940. Myself and nearly all others size wire from the 75 Deg C column, smaller wire, less copper, smaller conduit..the larger wire sizes from the 60 deg C column can certainly be used
I have know Mike Holt since 1996 and here is what he has to say
View attachment 2561179

I showed you the link:

https://www.ecmweb.com/national-electrical-code/qa/article/20896624/stumped-by-the-code-equipment-temperature-terminal-rating-for-sizing-conductors

 

[Patpowers]

In that article referring to table 310.15(b)(16) , as of 2020 NEC it becomes Table 310.16.

Anyhow, let’s take a look at this:

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.

(1) Equipment Provisions.​

The determination of termination provisions of equipment shall be based on 110.14(C)(1)(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 310.16 as appropriately modified by 310.12.

• (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 (140°F).
  • (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 (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.
  
  
• (b)
  Termination provisions of equipment for circuits rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following:
  • (1)
    Conductors rated 75°C (167°F)
  • (2)
    Conductors with higher temperature ratings, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors

 

[avargasm]

In that article referring to table 310.15(b)(16) , as of 2020 NEC it becomes Table 310.16.

Anyhow, let’s take a look at this:

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.

(1) Equipment Provisions.​

The determination of termination provisions of equipment shall be based on 110.14(C)(1)(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 310.16 as appropriately modified by 310.12.

• (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 (140°F).
  • (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 (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.
  
  
• (b)
  Termination provisions of equipment for circuits rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following:
  • (1)
    Conductors rated 75°C (167°F)
  • (2)
    Conductors with higher temperature ratings, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors

Yea, I'm in case (2):


(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.

 

[Patpowers]

Note it says one of the following, not all of the following. So only one of the “dotted” rules need apply.

But , if you manage to find a 60degree rated equipment that was the last lunch in the remains of a dug up dinosaur , than you do need to size Conductor under 60.

 

[wwhitney]

Yea, I'm in case (2):

Right, but as most equipment has 75C terminals, you may use case (3). By choosing case (2) over case (3), you are wasting copper, although reducing voltage drop.

Cheers, Wayne

 

[jap]

Anything is possible.

This pretty much answered the OP"s question in post #2.

JAP>

 

[avargasm]

This pretty much answered the OP"s question in post #2.

JAP>

That is correct.