Wiring for hot tub
#1
02-20-13, 12:30 PM
Wiring for hot tub
I need to know if I can run 6/3 romex cable from my panel to my hot tub. The tub is around 150 ft away from the panel and is an interior application. The tub although rated for 60 amps, the manufacturer says it draws max 54amps with all pumps running. Will the 6/3 with the loss factor be sufficient enough or do I have to upgrade to 4/3 romex. I will be installing a GFCI 10' away from the tub making the lenght of the run to around 140'..
#2
02-20-13, 01:40 PM
Welcome to the forums!
The voltage drop calculator I used gave me #2 copper for 300' for a 120V circuit, or #6 copper for 150' for a 240V circuit.
The length of the run is 150'. You need the 54 amps at the tub, not at the disconnect.
The voltage drop calculator I used gave me #2 copper for 300' for a 120V circuit, or #6 copper for 150' for a 240V circuit.
The length of the run is 150'. You need the 54 amps at the tub, not at the disconnect.
#4
02-20-13, 05:31 PM
Yes. Anything less than 3% is considered an acceptable result. Appliances are supposed to be designed to operate with voltage that is within 10%, each way, of their labeled voltage. That's 216V to 264V for your hot tub. 
It's not the best practice to go to either edge of that range, of course. But ~233V, if that's what you wind up with, should be OK.
It's not the best practice to go to either edge of that range, of course. But ~233V, if that's what you wind up with, should be OK.
#5
02-21-13, 11:40 AM
National electrical code requires that the wiring for hot tubs consist of a GREEN insulated ground wire of equal size to the other wires. ROMEX has a bare copper wire, one size smaller than the other wires. Hence, it would be a violating of code to use romex to wire a hot tub.
Mod Note: the grounding conductor can be bare for the interior wiring portion of the circuit.
Mod Note: the grounding conductor can be bare for the interior wiring portion of the circuit.
Last edited by pcboss; 02-23-13 at 02:07 PM.
#6
02-21-13, 01:01 PM
National electrical code requires that the wiring for hot tubs consist of a GREEN insulated ground wire of equal size to the other wires. ROMEX has a bare copper wire, one size smaller than the other wires. Hence, it would be a violating of code to use romex to wire a hot tub.
From the 2011 NEC (emphasis added):
680.21 Motors.
(A) Wiring Methods. The wiring to a pool motor shall comply
with (A)(1) unless modified for specific circumstances by
(A)(2), (A)(3), (A)(4), or (A)(5)....
(4) One-Family Dwellings. In the interior of dwelling units,
or in the interior of accessory buildings associated with a
dwelling unit, any of the wiring methods recognized in Chapter
3 of this Code that comply with the provisions of this
section shall be permitted. Where run in a cable assembly, the
equipment grounding conductor shall be permitted to be uninsulated,
but it shall be enclosed within the outer sheath of the
cable assembly.
(A) Wiring Methods. The wiring to a pool motor shall comply
with (A)(1) unless modified for specific circumstances by
(A)(2), (A)(3), (A)(4), or (A)(5)....
(4) One-Family Dwellings. In the interior of dwelling units,
or in the interior of accessory buildings associated with a
dwelling unit, any of the wiring methods recognized in Chapter
3 of this Code that comply with the provisions of this
section shall be permitted. Where run in a cable assembly, the
equipment grounding conductor shall be permitted to be uninsulated,
but it shall be enclosed within the outer sheath of the
cable assembly.
#8
02-23-13, 09:37 AM
No code applies locally except local code. National codes are guidelines only unless adopted in whole without amendments by local authorities having jurisdiction. CEC can vary from NEC which is what was referenced. Bottom line the only opinion that counts is the local inspector's opinion. Ask him to be sure. Also note there are differences sometimes between US and Canadian NM-b cable.
#10
02-23-13, 08:33 PM
Dr. Spa do you have a NEC cite for the grounding conductor size? Even in conduit using insulated wire it is code to use #10 for the EGC on a 60a circuit. Is there an exception in the NEC for Spas?
