Travelers and current carrying conductors

[Shockedby277v]

Are travelers considered current carrying conductors when derating? 2 ungrounded (phase A &B) 2 neutrals 4 travelers 2 switch legs 1 equipment ground. All #12 stranded THHN on 20amp breaker 277volt. I needed to add characters so now I am rambling …. Have to derate to 70% or 50%? table 310.15(B)(3)(a)

 

[infinity]

Short answer is no since one traveler will be carrying current and the other will not.

 

[Dennis Alwon]

This is a note at the bottom of the Table for current carrying conductor's

Number of conductors is the total number of conductors in the raceway or cable, including spare conductors. The count shall be adjusted in accordance with 310.15(E) and (F). The count shall not include conductors that are connected to electrical components that cannot be simultaneously energized.

 

[jap]

This is a note at the bottom of the Table for current carrying conductor's

What exactly does that mean?

In the OP's scenario there would actually be 1 traveler from each circuit that would be carrying current when the lights were on.

Would that make a difference?

JAP>

 

[winnie]

Travelers which are carrying current count toward the CCC number.

In common 3 an 4 way switching setups, you have 2 travellers but only 1 at a time is conducting. In this case the pair of wires counts as 1 CCC.

There are some strange 3 way setups where both travelers might conduct at the same time, in which case the pair wires would count as 2 CCC.

Jon

 

[ptonsparky]

Travelers which are carrying current count toward the CCC number.

In common 3 an 4 way switching setups, you have 2 travellers but only 1 at a time is conducting. In this case the pair of wires counts as 1 CCC.

There are some strange 3 way setups where both travelers might conduct at the same time, in which case the pair wires would count as 2 CCC.

Jon

I'm having a hard time wrapping my head around that. Can you post a diagram ?

 

[infinity]

What exactly does that mean?

In the OP's scenario there would actually be 1 traveler from each circuit that would be carrying current when the lights were on.

Would that make a difference?

JAP>

Yes it does in this example because if you only count two of the four travelers then the derating is 70%. (8 CCCs': 2 hots, 2 travelers, 2 neutrals, 2 switch legs) If you count all 4 travelers the derating is 50% (10 CCC'S) and the #12 conductors become 15 amp conductors instead of 20 amp conductors with the 8 CCC's.

 

[jap]

So in the OP's scenario where 1 traveler from each circuit is carrying current when each load is on meaning (2 travelers carrying current at the same time) shouldnt they be counted?

It was indicated before that they would not be counted.

JAP>

 

[infinity]

So in the OP's scenario where 1 traveler from each circuit is carrying current when each load is on meaning (2 travelers carrying current at the same time) shouldnt they be counted?

It was indicated before that they would not be counted.

JAP>

There are 4 travelers in the raceway. Only two can be energized simultaneously so only two count as CCC's when applying derating.

 

[jap]

There are 4 travelers in the raceway. Only two can be energized simultaneously so only two count as CCC's when applying derating.

Then I dont understand post #2.

JAP>

 

[infinity]

Then I dont understand post #2.

The implied question was if there are 4 travelers in a raceway do they all count as CCC's and the answer is no for the reason given in post #2.

 

[winnie]

I'm having a hard time wrapping my head around that. Can you post a diagram ?

Search for 'traveling bus three way'; here is an example: https://diy.stackexchange.com/questions/58678/coast-3-way-does-this-conform-with-code

The use is to provide constant power and switched power anywhere along a 4 wire line with switches at either end. In the cable you have the constant 'hot', the 'neutral', a 'switched hot', and a single 'traveler'. And as I describe it this way I realize that there aren't 2 travelers where only 1 counts as a CCC; but rather that this is a non-standard 3-way arrangement with only a single traveler.

-Jon

 

[jap]

The implied question was if there are 4 travelers in a raceway do they all count as CCC's and the answer is no for the reason given in post #2.

I took the implied question as do they count at all.

They dont "all" count, but, a couple of them do.

JAP>

 

[infinity]

I took the implied question as do they count at all.

They dont "all" count, but, a couple of them do.

JAP>

It would have been clearer if I said short answer, yes and no.