240.21(b) (3) (3) (sec. not protected)

[Peter Anderson]

Is there any rule about transformer secondary wired in wye. 240.21(b) (3) (3) (sec. not protected) beingin the same gutter as branch circuits. Similar to the rule 230.7 for serviceconductors. (other conductors in raceway).

I have a 75kva transformer 3ph 480 to 208 300kcmil, bigwires in gutter and they ran 12ga branch circuit wires in there also. This seems so wrong but Ican’t find any article against it. Exceptmaybe 110.27 (b) preventing physical damage, but it is protected in the raceway already.

 

[Dennis Alwon]

I don't think it is an issue unless the secondaries are service conductors.

 

[Peter Anderson]

I don't think it is an issue unless the secondaries are service conductors.

I realize they are not service conductors only because they don’t enter the building. But it is a separately derived system just like an incoming service. In the event the branch circuits need to be worked on we would be exposed to a very high arc flash hazard . Or in the event of a fault the branch circuits it would be passing extream amperage to all parts of the run and Utilization equipment

 

[don_resqcapt19]

I realize they are not service conductors only because they don’t enter the building. But it is a separately derived system just like an incoming service. In the event the branch circuits need to be worked on we would be exposed to a very high arc flash hazard . Or in the event of a fault the branch circuits it would be passing extream amperage to all parts of the run and Utilization equipment

There is no restriction in the code on mixing those conductors.

The only restriction involves service conductors, and that is more driven by the utilities intent to make it more difficult to steal power than by the safety issues.

 

[kwired]

There is no restriction in the code on mixing those conductors.

The only restriction involves service conductors, and that is more driven by the utilities intent to make it more difficult to steal power than by the safety issues.

I don't know that I agreee on the stealing power issue. If past metering equipment you can't really steal power if you tap into those conductors.

POCO's only want to protect access to unmetered conductors

 

[GoldDigger]

Typical service conductors are not even weakly protected by primary side fusing (no NEC requirements there.)
Typical SDS secondary conductors are at least partially protected (i.e. short circuit but not overload) by primary OCPD.