Barbqranch
Senior Member
- Location
- Arcata, CA
- Occupation
- Plant maintenance electrician Semi-retired
I am involved with planning the moving of a piece of equipment in our plant. Our power is 208Y/120, and there is a transformer that raises this to 480 V 3p for this one cutting machine. Machine name plate calls for 50 A (41.5 kva) and the transformer is 45 kva. Machine draws full power only for a couple of minutes every 10 minutes or so. All this was installed before I was hired, and there is much evidence around here that things were just done, not planned.
Transformer currently is on a 100 A 3pole breaker, not in line of sight, with no other disconnects. At the very least, I need to install a lock on the breaker. Does this transformer require a fused disconnect on the output, and could you please direct me to the area of the NEC (2011) where I can learn more about this. Should I be concerned about a fuse blowing and dropping a phase out to the machine, if I were to install 50 A fuses? (Machine actually draws a peak of 42 amps, at least when I checked.)
To all of you who know so much more than I do, I owe a lot. It has been an education being on here. Thanks.
Transformer currently is on a 100 A 3pole breaker, not in line of sight, with no other disconnects. At the very least, I need to install a lock on the breaker. Does this transformer require a fused disconnect on the output, and could you please direct me to the area of the NEC (2011) where I can learn more about this. Should I be concerned about a fuse blowing and dropping a phase out to the machine, if I were to install 50 A fuses? (Machine actually draws a peak of 42 amps, at least when I checked.)
To all of you who know so much more than I do, I owe a lot. It has been an education being on here. Thanks.