Needing to supply power to a control box for 2x 15,000 Watt immersion heaters (resistive load). Service is 3 phase 208v. Heaters will only be on for ~1 hour per day. Total Amp draw of both heaters is around 83. I've sized the circuit for 100 Amp breaker, 3x #3 AWG hots and 1x #6 AWG ground, 1-1/4" EMT.
Looks like I have 2 options:
Looks like I have 2 options:
- Make a 100 amp receptacle in a box for Hubbell pin/sleeve type connectors. This is the more preferred way as it gives flexibility for the placement of the control box and makes it easy to take down for servicing. I'd like to keep the junction box for this receptacle as small as possible. Questions arise as to how small this junction box can be since it's unclear if and how NEC 314.28 applies as there will be no wires passing through the box. All conductors will terminate at the receptacle. I can also have the conduit enter the back of the box (through the wall and opposite a cover plate), bringing Table 312.6(A) into effect.
- Pipe the 1-1/4" EMT directly to the box. Less desirable for reasons stated above. It also makes the control box part of the building wiring, which would ideally be avoided. Not sure of any subtle or lesser known code quirks this might bring up. If this method is necessary, is there a good way to transition from EMT to NM flex conduit without requiring a large box as per NEC 314.28?