Double Tapping at Main (600 Amp multi-phase)

Just came across this today and since I don’t do a lot of commercial inspections I thought I’d get some professional opinions. Info: 15K sq.ft. bldg. built in 1950’s. I’m calling it a 600 amp (based on fuse sizes) multi-phase w/double tapping at the main. I also could not confirm or find where these smaller wires go to within the building. Thoughts and comments appreciated.

That’s a 120/240, 4 wire Delta service. High leg to ground (B phase) is ~208 volts.

It looks OK on the line side–appears to be parallel fed as long as wire size is correct.

Thanks for the info guys. I was particularly interested in what you (or anyone else) thought about the double taps at the main lugs (below fuses).

Any time I see this I write it up as such but because these are multiple lug connections on a commercial panel / installation, I didn’t know if this could somehow be considered an acceptable connection.

That connection is not acceptable. Lugs that can accept two conductors have to be listed as such. Unless that’s some type of factory wiring the use of multiple conductors under that lug is not permitted.


Thanks, I appreciate your help. That’s what I was thinking but it never hurts to get another opinion.

And I promise you…that’s not factory wiring:)

Thank you for the update. I was wondering is someone was going to say something about that.