goldstar
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
With respect to it not being considered a service panel, I don't see it that way. That original main breaker panel is still your service panel. Even though you left the main breaker in it (with a service rated ATS in front of it) and separated the EGC's and neutrals, the only purpose the existing main breaker serves at that point is as a disconnect means. It might as well be a molded case switch. It would be no different than having a main breaker disconnect nippled into a meter enclosure and SER leaving that to feed a main lug panel on the opposite side of the house. You'd have to feed your range, etc. out of that panel. You can't wire it back to the disconnect. So, if the original installer used SER cable to feed the range then you would already have moved the EGC to the ground bar.You have to land the white on the neutral bus, it is current carrying, but it is also the EGC for a three wire range circuit where permitted.
But the circuit must originate in service equipment.
Check out the exception to 250.140 that tells us where a 3 wire range circuit is permitted. Condition 3 of the exception says the circuit must originate at service equipment. So if you convert your existing service panel to a sub panel when installing a service rated ATS, you can no longer supply the existing 3 wire range circuit from that panel.
When inspectors start failing you for this then it's all over. You might as well pack up your tools and open a 7-11. It's hard enough convincing a HO to part with $10K plus for their new gen set, now we have to try and convince them that we'll have to rip open walls and ceilings so that we can replace the wiring to their electric ranges, ovens and dryers? Irrespective of what the Code says in this case you'll have a hard time selling this one IMHO. I can envision numerous complaints at town council meetings and possibly law suits. I think it's a far stretch to fail a contractor for chicken s**t stuff like this.
Just my opinion.