Can main service panel contain through-wiring from another service?

TimWA

Member
Presently two dwellings on the property sharing a 200A post-mount Mobile pack (meter/main). Larger house off the 200A feed-through lugs, smaller off a 100A 2P breaker.

Adding a 100A mobile-pack on the back of the same post to dedicate to the smaller dwelling so they can have their own utility bills. Can I splice onto the 100A feeder residing in the 200A enclosure and run it into the new panel via PVC nipple joining the two? Or do I have to disconnect the 100A raceway entirely and swing it over to the new panel.
 

GoldDigger

Moderator
Staff member
Presently two dwellings on the property sharing a 200A post-mount Mobile pack (meter/main). Larger house off the 200A feed-through lugs, smaller off a 100A 2P breaker.

Adding a 100A mobile-pack on the back of the same post to dedicate to the smaller dwelling so they can have their own utility bills. Can I splice onto the 100A feeder residing in the 200A enclosure and run it into the new panel via PVC nipple joining the two? Or do I have to disconnect the 100A raceway entirely and swing it over to the new panel.
The Canadian Electrical Code (CEC) feels very strongly about mixing service (no OCPD) conductors with any other conductors inside a panel as well as in a raceway. Their main panel has a compartmented space for the service wiring and it cannot extend into the main body of the panel enclosure.
The NEC does not feel that strongly about it yet, although UL is leaning in that direction. It comes down to what your AHJ feels about it.
I think that it is common right now to extend service conductors through a main panel to another device. Whether I would choose to do it would depend on the alternatives.
 

augie47

Moderator
Staff member
Location
Tennessee
If your nipple enters in the feeder section of each panel (away from the service conductors) I would say you plan is compliant (provided you don't exceed the fill discussed in 312.8).
To me it's a bit undesirable since you are mixing lads off two separate meters but I can not seem where its a violation. I would, as GoldDigger suggests, run it by your AHJ.
 
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