shawnbebout
Member
So I took a job as a maintenance electrician in a factory. I noticed a green ground screw bonding the neutral block, in the disconnect, on the secondary side of the transformer. 277/480 step down to 120/208. Separately derived system, not the service by a long shot. I know the bonding should take place at the source, not in the first disconnect.
So I pulled the cover of the transformer yesterday. They took the 2 neutrals (parallel) from the xo bar to a 4 barrel lug (mounted to the left side of transformer case) then off to the secondary disconnect. They took all the grounds, to a 3 barrel lug, mounted on the right side of the case. Building steel, and the grounds in the pipes. There was no actual wire connecting the neutral and ground lugs. I assume they were using the metal case of the transformer as a bonding jumper.
I reworked it, so the proper bonding is now done.
I guess my question is, was this legal back in the early 90's? I know it wouldn't fly today. Also they had the "service disconnect" sticker on the secondary side disconnect.
So I pulled the cover of the transformer yesterday. They took the 2 neutrals (parallel) from the xo bar to a 4 barrel lug (mounted to the left side of transformer case) then off to the secondary disconnect. They took all the grounds, to a 3 barrel lug, mounted on the right side of the case. Building steel, and the grounds in the pipes. There was no actual wire connecting the neutral and ground lugs. I assume they were using the metal case of the transformer as a bonding jumper.
I reworked it, so the proper bonding is now done.
I guess my question is, was this legal back in the early 90's? I know it wouldn't fly today. Also they had the "service disconnect" sticker on the secondary side disconnect.