milemaker13
Senior Member
- Location
- Suburbs of Chicago
We are moving 3 old spot welders. These are old Stancos with a heavy base and long copper weld arms. Two are 50 KVA and the 3rd is 30 KVA. They operate at 208v single phase.
Currently they are tied into 80 amp breakers with short runs of #6 THHN. The 30 KVA has a 60 amp breaker and #6. The runs are 15' or less.
They want them moved to a location that will require ceiling drops, so the runs will be much longer.... longest being about 80'.
I am having a hard time nailing down a solid answer on conductor and OCP sizing. To make matters worse, I don't have a code book in front of me to read what exactly 630. says about it.
What I want to avoid is spec'ing #6 in 3/4 EMT (cuz that's what's there) only to change my tune tomorrow.
Just because it has been working well for years doesn't mean it was done correctly!
Any insight on installing medium sized resistance spot welders?
Currently they are tied into 80 amp breakers with short runs of #6 THHN. The 30 KVA has a 60 amp breaker and #6. The runs are 15' or less.
They want them moved to a location that will require ceiling drops, so the runs will be much longer.... longest being about 80'.
I am having a hard time nailing down a solid answer on conductor and OCP sizing. To make matters worse, I don't have a code book in front of me to read what exactly 630. says about it.
What I want to avoid is spec'ing #6 in 3/4 EMT (cuz that's what's there) only to change my tune tomorrow.
Just because it has been working well for years doesn't mean it was done correctly!
Any insight on installing medium sized resistance spot welders?