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Thursday, April 13, 2023
Question:
Hi Charlie. We are we are wiring to a new spa in the backyard of single-family dwelling. The spa manufacturer’s installation instructions require minimum 6AWG copper conductor for the ungrounded conductors, the grounded conductor, and the equipment ground, for their spa with a 40A OCPD.
From the service panel there is a 40A supply consisting of:
- 40A Circuit Breaker OCPD
- 2- #8 AWG copper ungrounded
- 1- #8 AWG copper grounded (Neutral) conductor
- 1- #10 AWG copper equipment grounding conductor
This supply is feeding a 2-circuit main lug, Hot tub style 3R device with a 40A GFCI OCPD installed. From the load side of the 40A GFCI OCPD, there are #6 AWG copper conductors installed in accordance with the installation instructions. Would this installation comply with the manufacturer’s installation instructions? Is supply to the line side of the 40A GFCI technically a feeder? Is the load side is the 40 GFCI OCPD a branch circuit? Thanks, Mark Binder
A
Answer:
Hello Mark, thank you for the question. The manufacturer's installation instructions are part of the listing of the equipment, as such, they will need to be complied with to maintain the spa’s listing, even if they are above and beyond the minimum installation requirements of the NEC®. The specific wording used (i.e., branch circuit conductors, vs just conductors) in the installation instructions will also be key in the application.
In the example you described in your question, and assuming that the “Hot tub Style device” is a 3R, 2-circuit load center, then technically, the supply to the 3R, 2-circuit loadcenter, meets the Article 100 definition of a Feeder - All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch circuit OCPD.
The conductors on the load side of the 40A GFCI/OCPD technically meets the Article 100 definition of a Branch Circuit – The circuit conductors between the final OCPD protecting the circuit and the outlet(s).