CrankyOldMan
Plastic
- Joined
- Sep 6, 2017
I've seen mention of it in a few other places but I haven't found a detailed answer for running a neutral along with the center-tapped delta output from a RPC. The plan is to add outlets on the machine instead of running extra leads to the walls or putting in transformers. A 240 Delta to 208Y transformer is cost prohibitive at this point.
The current setup: 5HP American Rotary panel with a 3HP idler. Shop equipment is all 1 - 1.5 HP stuff but I may add something larger later and want to future-proof the wiring now.
The plan: Run a SO 5-wire cable from the RPC to the machine in use. Connect things using twist-lock NEMA plugs/receptacles. I've gone over the requirements for conductor sizing and overcurrent protection and understand the math but don't know what exceptions/special cases apply here. The calculations will also depend on what solution I use for the 110 outlets so I need to sort that out first.
The questions:
* NEMA L21 devices are spec'd for 120/208Y. Is there any issue with using them for 240 high leg--other than the marking being wrong? Should I go up to L22 for higher voltage rating?
* Since it's not hardwired, does this negate the NEC tables for dedicated motor circuits and just use the standard ampacity and derating tables?
I've got more questions but they also hinge on what connector to use and what NEC tables apply.
Thanks!
The current setup: 5HP American Rotary panel with a 3HP idler. Shop equipment is all 1 - 1.5 HP stuff but I may add something larger later and want to future-proof the wiring now.
The plan: Run a SO 5-wire cable from the RPC to the machine in use. Connect things using twist-lock NEMA plugs/receptacles. I've gone over the requirements for conductor sizing and overcurrent protection and understand the math but don't know what exceptions/special cases apply here. The calculations will also depend on what solution I use for the 110 outlets so I need to sort that out first.
The questions:
* NEMA L21 devices are spec'd for 120/208Y. Is there any issue with using them for 240 high leg--other than the marking being wrong? Should I go up to L22 for higher voltage rating?
* Since it's not hardwired, does this negate the NEC tables for dedicated motor circuits and just use the standard ampacity and derating tables?
I've got more questions but they also hinge on what connector to use and what NEC tables apply.
Thanks!