Table 310.15(B)(3)(a)

[jbolen]

I have some 1 1/2 EMT with 42 #12 xhhw current carrying conductors. What is maximum over current device for these circuits

 

[xformer]

I have some 1 1/2 EMT with 42 #12 xhhw current carrying conductors. What is maximum over current device for these circuits

This in a dry or wet location?

 

[david luchini]

This in a dry or wet location?

Is it going to make a difference with 42 ccc's?

 

[Dennis Alwon]

This in a dry or wet location?

It is probably xhhw-2 which would not matter if it is wet or dry

 

[Dennis Alwon]

10 amp overcurrent protective device if it is 90C. You need to increase the wire size and then reduce the number of conductors or use 2 runs of conduit

 

[xformer]

Is it going to make a difference with 42 ccc's?

To properly apply 310.15B16 one must first look at 310.104A.

In a dry location starting ampacity of #12 is 30 amps.
In a wet location starting ampacity of #12 is 25 amps.


I came up with 10 amps - dry / 5 amps wet.

 

[david luchini]

I came up with 10 amps - dry / 5 amps wet.

I came up with 15 amps - dry or wet

 

[Dennis Alwon]

To properly apply 310.15B16 one must first look at 310.104A.

In a dry location starting ampacity of #12 is 30 amps.
In a wet location starting ampacity of #12 is 25 amps.


I came up with 10 amps - dry / 5 amps wet.

I think David's point is there probably isn't a 10 or 5 amp overcurrent protective device unless fuses are used. Not likely

 

[xformer]

I came up with 15 amps - dry or wet

How so?

 

[xformer]

How so?

:slaphead::slaphead::slaphead:

 

[Dennis Alwon]

I came up with 15 amps - dry or wet

Are you going with next size up rule? The load of course would have to be less.

 

[LarryFine]

I would ask what the capacity needs to be to serve the loads, and work backwards from there.