Smash
Senior Member
- Location
- Philadelphia suburbs, PA USA
Objective supply 3phase 480V power for two loads one draws 12 amps will fuse at 30A the other has a 3pole 50amp breaker. Draws 22.5 amps
I already ordered a 208V Delta pri and 480V wye secondary 75KVA step up transformer. Here’s my plan I will run 2/3 MC about 110’ from the 208V panel will install a 3pole 100A breaker voltage drop will be within peramiters with #2 wire, at the load side a 3phase 100A 600V service disconnect to feed trans primary. Out of transformer to a fusible disconnect 10’ away to feed crane. Out of trans again (double lugs) about 15’ to non fusible disconnect to feed the 3pole 50A breaker load. There are no neutrals needed. So I do not plan to use the XO terminal. The 2/3 MC cable has a #8 stranded ground that will go to the HO lug in the transformer than bond to unit case. ? Then will run a separate # 6 EGC back to the source and ground. Little fuzzy on the grounding and bonding and when is it concidered a SDS at the source 110’ away or at the disconnect sitting next to transformer ? Also would run a # 6 solid from trans case to structure steel. Is this install ok once I figure out the grounding aspect. Gets confusing to me when talking delta/wye and SDS. You guys all helped me out to get this job I was able to hold a intelligent conversation of what was needed and now I want to check and double check to make sure I’m correctly doing the install. Ty in advance.
I already ordered a 208V Delta pri and 480V wye secondary 75KVA step up transformer. Here’s my plan I will run 2/3 MC about 110’ from the 208V panel will install a 3pole 100A breaker voltage drop will be within peramiters with #2 wire, at the load side a 3phase 100A 600V service disconnect to feed trans primary. Out of transformer to a fusible disconnect 10’ away to feed crane. Out of trans again (double lugs) about 15’ to non fusible disconnect to feed the 3pole 50A breaker load. There are no neutrals needed. So I do not plan to use the XO terminal. The 2/3 MC cable has a #8 stranded ground that will go to the HO lug in the transformer than bond to unit case. ? Then will run a separate # 6 EGC back to the source and ground. Little fuzzy on the grounding and bonding and when is it concidered a SDS at the source 110’ away or at the disconnect sitting next to transformer ? Also would run a # 6 solid from trans case to structure steel. Is this install ok once I figure out the grounding aspect. Gets confusing to me when talking delta/wye and SDS. You guys all helped me out to get this job I was able to hold a intelligent conversation of what was needed and now I want to check and double check to make sure I’m correctly doing the install. Ty in advance.