Electrical history question

[Gac66610]

When was a four wire feeder required for a sub-panel installed in a residence? Homeowners have a 200a main in the attached garage and a sub-panel in the basement fed with a 3 wire feeder and a home inspector noted it, the house was built in 1960, but I can not say when the sub-panel was installed.

Thanks,
Greg

 

[Ponchik]

I THINK it was 1999 or 2002 cycle.

 

[Strathead]

When was a four wire feeder required for a sub-panel installed in a residence? Homeowners have a 200a main in the attached garage and a sub-panel in the basement fed with a 3 wire feeder and a home inspector noted it, the house was built in 1960, but I can not say when the sub-panel was installed.

Thanks,
Greg

Are you asking about a panel that has 240/120 single phase? As in, the feeder you question doesn't run a separate ground and neutral? If so, I don't think it has been "allowed" by code since the design of a system with a bonded service. OTOH, it has been done, especially from a disconnect or a meter outside a structure to a panel located further than the allowed "inside nearest the entrance" many many times. There was a time when it was allowed between buildings, but not within a single structure, as far as I know.

 

[kwired]

I THINK it was 1999 or 2002 cycle.

Was before then, not sure how long before but guessing at least into 1960's or even 1950's.

There are many older installs that don't follow that rule, but I don't think most were compliant at the time of install. Inspections just didn't look at that very hard until about the 1980's or so. My thoughts is the rule was there for a long time but education on some of those details was pretty poor.

 

[Gac66610]

Thanks for the responses, I believe it was in to 90's that we started separating the grounds and neutrals at the range and dryer receptacles, maybe even the feeder for a detached garage. I wasn't sure of "in the same dwelling" thought I'd try and find out before replacing the 3 wire to a 4 wire feeder

 

[infinity]

For a sub-panel in an attached structure in 1960 an EGC was required. The 1959 NEC {250-61} states "The grounded circuit conductor on the load side of the service disconnecting means shall not be used for grounding equipment, cable armor, or metal raceways as provided in paragraph 250-57b-3, and section 250-60. Neither of the mentioned exceptions would apply to the installation outlined in the OP.

 

[kwired]

Thanks for the responses, I believe it was in to 90's that we started separating the grounds and neutrals at the range and dryer receptacles, maybe even the feeder for a detached garage. I wasn't sure of "in the same dwelling" thought I'd try and find out before replacing the 3 wire to a 4 wire feeder

Pretty sure it was 1996 NEC that started requiring separate ground/neutral to all ranges and dryers, with exceptions for existing installations.

Separate buildings, was not an all out requirement until either 2005 or 2008, but there had been wording for some time requiring separate equipment grounding if there were other parallel conductive pathways between the two buildings.

 

[Smart $]

For a sub-panel in an attached structure in 1960 an EGC was required. The 1959 NEC {250-61} states "The grounded circuit conductor on the load side of the service disconnecting means shall not be used for grounding equipment, cable armor, or metal raceways as provided in paragraph 250-57b-3, and section 250-60. Neither of the mentioned exceptions would apply to the installation outlined in the OP.

I agree it was long ago. The main thing is if the sub panel is in the same building. It wasn't until the new millennium that an EGC was required for a separate structure.

 

[James L]

When was a four wire feeder required for a sub-panel installed in a residence? Homeowners have a 200a main in the attached garage and a sub-panel in the basement fed with a 3 wire feeder and a home inspector noted it, the house was built in 1960, but I can not say when the sub-panel was installed.

Thanks,
Greg

what kind of inspection was it? Inspection of permitted work or home sale?

what do you mean by inspector noted it?

private home inspectors have no jurisdiction, they simply make suggestions. No one is obligated to this kind of inspector.

however,
that also means there's really no basis for seeking a grandfather clause in this type of scenario.

if an inspector mentioned it and the homeowner wants the most code compliant scenario, get it properly grounded regardless of when the house was built