docj67
Inactive, Email Never Verified
- Location
- Berkeley California USA
Hello veterans!
Appreciate this forum so much.
I'm auditing a job against 230-70-75
I have a building with old disconnects that are candidates for replacement
Each one is a dual two pole 50 feeding two subpanels in it's corresponding dwelling unit.
Each one's two two pole 50's are not handle tied so it takes two hands to execute a simulatneous disconnect of all ungrounded conductors.
My understanding of 230.72 A is now a tad confused. It seems as if 6 simultaneously throwable breakers is the biggest qualifiable config for a main disconnect and that any more then one two pole breaker ( which is what constitutes 95% of what I have seen in the field either as off main row main bus disconnect or backfed to bus main disconnect ) must be tied together. Or are you allowed 6 motions of the hand meaning a maximum of 6 breakers that can each be thrown with one move of the hand. Thanks.
Also having never read detail on the requirements for "disconnection means for the grounded conductor" until recently, I'd like to check that my interpretation of 230.75 is such that as long as neutral bar is a standard screw held system you are good bc i never seen a neutral fed thru a disconnect except for maybe once or twice with three phase....
My old place had 3 units each with a "main disconnect" that you could not disconnect all circuits with two hands. I assume this does not qualify at all as a main disconnect--they were in fact small fed pacific panels dating to the late 40's. My ex landlord has since cleaned it up part of it...
I'm grateful to be able to have this forum because is the part of the work of an electrician I enjoy the most and will continue to attempt to develop a specialty in. This question is also generated by the same building that I worked on recently that necessitated me delving into the world of grounding and an earlier post here..in different sub forum.
Thx so much.
Appreciate this forum so much.
I'm auditing a job against 230-70-75
I have a building with old disconnects that are candidates for replacement
Each one is a dual two pole 50 feeding two subpanels in it's corresponding dwelling unit.
Each one's two two pole 50's are not handle tied so it takes two hands to execute a simulatneous disconnect of all ungrounded conductors.
My understanding of 230.72 A is now a tad confused. It seems as if 6 simultaneously throwable breakers is the biggest qualifiable config for a main disconnect and that any more then one two pole breaker ( which is what constitutes 95% of what I have seen in the field either as off main row main bus disconnect or backfed to bus main disconnect ) must be tied together. Or are you allowed 6 motions of the hand meaning a maximum of 6 breakers that can each be thrown with one move of the hand. Thanks.
Also having never read detail on the requirements for "disconnection means for the grounded conductor" until recently, I'd like to check that my interpretation of 230.75 is such that as long as neutral bar is a standard screw held system you are good bc i never seen a neutral fed thru a disconnect except for maybe once or twice with three phase....
My old place had 3 units each with a "main disconnect" that you could not disconnect all circuits with two hands. I assume this does not qualify at all as a main disconnect--they were in fact small fed pacific panels dating to the late 40's. My ex landlord has since cleaned it up part of it...
I'm grateful to be able to have this forum because is the part of the work of an electrician I enjoy the most and will continue to attempt to develop a specialty in. This question is also generated by the same building that I worked on recently that necessitated me delving into the world of grounding and an earlier post here..in different sub forum.
Thx so much.
Last edited:
