single phase panel in a 3 phase system?

[wwhitney]

I agree, so, maybe the rule for the spare conductor needs to be rethought.

It's not the spare conductor rule we disagree about it, it's the definition of circuit conductor for applying 310.15(B) to determine whether the neutral conductor is a CCC.

Cheers, Wayne

 

[winnie]

IMHO a reasonable code change is that a set of conductors with spares should be treated as though the spare are used as expected.

So an extra pair of wires in a conduit for a future circuit counts as 2 additional CCC, because the expected use is to add a new circuit.

But an extra 4 wires (wye full boat) would count as 3 CCCs.

And this feeder with 4 wires would count as 3 CCCs because if the 4th wire is used (in a reasonably expected fashion) the neutral would cease to count.

Jon

 

[kwired]

Heck, some code violating ding dong might install a 1p 20a breaker in the load end panel and tie a #12 Thhn to the spare feeder conductor to turn on an indicator light back at the line side feeder panel for a proof positive indicator they had voltage on that particular buss bar at the load end panel.

Uh-oh,, our spare just became an actual current carrying conductor, and, that would make 4 wouldn't it?

Jap>

Make it a control style indicator light and call it a Art 725 control circuit and you maybe don't need to consider that conductor for ampacity adjustment purposes? Certainly more believable than if the indicator light were a 1000 watt luminaire

 

[kwired]

I did not read all the posts so don't know what all came up, but if you have a feeder circuit like what is in question here with one phase conductor not actually in use, there isn't all that much you can use it for other than maybe the mentioned return for an indicator or to actually utilize the third phase within the feeder circuit. You are not going to use it for an additional feeder or a branch circuit (properly anyway) without also adding at least one other conductor to be part of the same feeder or branch circuit. Switch return loop is about all it is good for for options outside of using it as the third phase conductor.

 

[Joethemechanic]

I'm still for reidentifying it with green tape and connecting it to the ground bar at each end

 

[jap]

I'm still for reidentifying it with green tape and connecting it to the ground bar at each end

I'm for leaving it like it is in the hopes that someday the spare conductor can be utilized for the installation of a 3ph Panel.

Jap>

 

[Joethemechanic]

I'm for leaving it like it is in the hopes that someday the spare conductor can be utilized for the installation of a 3ph Panel.

Jap>

Well that was kinda my thought. I just figured you could just pull the green tape off and reconnect it to the 3rd phase whenever you needed it. If it's on the ground bar, it's not a current carrying conductor

 

[LarryFine]

My interpretation is that the spare conductor is "countable" rather than "counted."

Meaning that it is to be considered as a CCC as it normally would be, not absolutely.

 

[jap]

My interpretation is that the spare conductor is "countable" rather than "counted."

Meaning that it is to be considered as a CCC as it normally would be, not absolutely.

I'm with you Larry.

Jap>

 

[winnie]

My interpretation is that the spare conductor is "countable" rather than "counted."

Meaning that it is to be considered as a CCC as it normally would be, not absolutely.

I don't think the code explicitly says this, but since this interpretation matches what I was proposing as a change, I'm on board

-Jon

 

[jap]

Well that was kinda my thought. I just figured you could just pull the green tape off and reconnect it to the 3rd phase whenever you needed it. If it's on the ground bar, it's not a current carrying conductor

That's the thing.

During this whole thread we were never informed of the load, the size of the feeder, or the size of the conductors.

It could be a 100 amp feeder or a 1000 amp feeder for all we know, and, landing the spare conductor or conductors as an EGC may be more of a task than what it's worth to satisfy a rule that may or may not need satisfied to begin with.

It's just simply odd to see a phase of a 3ph panel feeder capped off.


JAP>

 

[acrwc10]

That's the thing.

During this whole thread we were never informed of the load, the size of the feeder, or the size of the conductors.

It could be a 100 amp feeder or a 1000 amp feeder for all we know, and, landing the spare conductor or conductors as an EGC may be more of a task than what it's worth to satisfy a rule that may or may not need satisfied to begin with.

It's just simply odd to see a phase of a 3ph panel feeder capped off.


JAP>

the feeder is 200 amp

 

[jap]

the feeder is 200 amp

Well It is getting close to Halloween, so,
The panel was labeled as a 120/240v 1ph. panel
There were only 1p and maybe 2p breakers in the panel leading one to believe it was a 120/240v 1ph panel.
Yet, when you took the cover off found out that is was actually a 120/208v 1ph panel disguised as a 120/240v 1ph panel.
And, is absolutely not a 120/208v 3ph 4w panel in any way shape or form.
Why?
Because it hasn't been connected as such.

JAP>

 

[winnie]

And then someone went and snuck a NOS delta breaker in

 

[LarryFine]

Yet, when you took the cover off found out that is was actually a 120/208v 1ph panel disguised as a 120/240v 1ph panel.

What could you see with the cover off that told you this? What is the visible difference???

 

[jap]

What could you see with the cover off that told you this? What is the visible difference???

Because you saw the capped off phase and put a meter on it because you thought it was a 3ph 240v Delta feeder.

JAP>