Conduit with shared branch circuits from separate services

[tw1156]

Can a single conduit share branch circuits that are derived from separate services? For example; there is a service set for exterior lighting and branch circuits serving those lights. A second service set up in a location with branch circuits serving various receptacle locations outside. Their branch circuits share the same conduit for some underground runs and same pull box in various locations.

By definition, only the Branch circuit conductors, 1000V or less, will be sharing the same conduit, but they are from separate services and the main service disconnects are not located within sight of each other.

300.3(C) says" Conductors of different systems", which would seem to permit it, but I do not believe that's the correct section, but the closest I could find.

 

[infinity]

Not a problem, are these panels actual fed from different services from the utility?

 

[tw1156]

Not a problem, are these panels actual fed from different services from the utility?

Yes; they are fed from two separate locations on a site from overhead transformers. The reason I ask these questions is it seems that the NEC would not want someone working in an area thinking they disconnected the power source to their system they were working on and still have a hazard present. Perhaps I was thinking too much into it.

 

[JFletcher]

Conduit can indeed have wiring from different panels at different voltages... All equipment that I have ever seen with multiple voltages or power feed sources have warning stickers to indicate such.

 

[tom baker]

The reason I ask these questions is it seems that the NEC would not want someone working in an area thinking they disconnected the power source to their system they were working on and still have a hazard present.

Electricians should be considered qualified and know how to test for voltage.

 

[tw1156]

Electricians should be considered qualified and know how to test for voltage.

Let me ask this question in a separate way; would you see any issue if these were separate tenants that shared the same conduit for their branch circuits supplied by separate services? Neither tenant had access to the others main panel. Thanks for all the answers though so far.

 

[petersonra]

Can a single conduit share branch circuits that are derived from separate services? For example; there is a service set for exterior lighting and branch circuits serving those lights. A second service set up in a location with branch circuits serving various receptacle locations outside. Their branch circuits share the same conduit for some underground runs and same pull box in various locations.

By definition, only the Branch circuit conductors, 1000V or less, will be sharing the same conduit, but they are from separate services and the main service disconnects are not located within sight of each other.

300.3(C) says" Conductors of different systems", which would seem to permit it, but I do not believe that's the correct section, but the closest I could find.

JMNSHO, but a "system" is not the same thing as a "service".

There is also a big difference between seperate services and separate service conductors that are the same service.

 

[kwired]

JMNSHO, but a "system" is not the same thing as a "service".

There is also a big difference between seperate services and separate service conductors that are the same service.

I agree.

OP did say this was two separate services not within sight of one another - which does leave one asking if they are allowed to be separate services or not. If same voltage, and other characteristics they generally must have the service disconnecing means in same location.

There also is requirements when you do have multiple supplies to a facility to identify other sources at each service disconnect location, though that alone doesn't necessarily help you know there are circuits from two sources if you are in the common junction box somewhere away from the service disconnecting means.

Let me add that since there is a second service there is a second system - has to be for the second service to be allowed even if both supplied by same source.

we also must identify conductors by system and phase when there is multiple voltage systems present.