Subpanel Unsafe?

[Dan Shewell]

I recently inspected a 80 year old house that main electric panel was located in a detached garage ten feet from the house. The main panel was rated for 200 AMP and had a 100 AMP 240-volt feed to a subpanel in the house. The subpanel in the house had no main breaker and required more than six breakers to turn off power to the house. Would you call out the subpanel in the house as unsafe, and recommend a profesessional electrician evaluate the subpanel?

Dover, DE

[mnahrgang]

No. The main panel was where the main shut off was. This is no more "unsafe" than if there were no sub panel, and all the breakers were in the garage.

[mthomas2]

1) In my experience, there is a good possibility such a system is improperly bonded/grounded by current standards, and perhaps even by the standards in effect at the time it was installed.

2) This type of installation (for example a disconnect out the pole at the end of the driveway) is more common in rural and outer suburban areas, and AHJs in some more urban areas may not accept a service disconnect for a main structure in a detached auxiliary structure.

3) IMO, reports should explicitly document all situations were an energized panel or circuit my not be obvious to occupants , ex: the attached is from a report last week, where there was no OCPD ahead of a load-side panel:

[Joe Farsetta]

The subpanel in the house had no main breaker and required more than six breakers to turn off power to the house.

There is no requirement for a main disconnect in any subpanel, regardless of what it feeds or how many breakers it has.

As far as the post warning of improper grounding or bonding, ensure that the sub is fed with four conductors, with the grounds and neutrals segregated in the sub-panel. Look for the floating neutral bus bar...

[Brian A. MacNeish]

Originally Posted by jfarsetta

There is no requirement for a main disconnect in any subpanel, regardless of what it feeds or how many breakers it has.

As far as the post warning of improper grounding or bonding, ensure that the sub is fed with four conductors, with the grounds and neutrals segregated in the sub-panel. Look for the floating neutral bus bar...

Do you mean "3 conductors and a ground"?