Wire gauge for hot tub

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Old 08-20-15, 12:38 PM
J
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Wire gauge for hot tub

I have a neighbour/friend putting in a hot tub and had a few questions about the wiring he will need.

The hot tub shell has a sticker that mentions: Current - 40A, Circuit Breaker - 50A, Wiring - #6AWG. It will not quite be a 70ft run from the board via a GFCI. Looking at the power pack (which I'm not certain is the original) it lists the current for each component. The heater, at 17A, and Pump #1, at 14A. The Ozonator, circulation pump, Pump #2, and blower are all features that are not installed. With that in mind, a 50A breaker with #6 seems less safe than a 40A breaker on #8... Max current is likely closer to 32A than 40A. For a code compliant install can this be done on #8 or must the wiring reflect the devices sticker?

Also, looking at Table 19 in the CEC I wondered which category best describes the run of wire that will be under his house (crawl space) to the GFCI. And, the tub has a rough cut hole in the skirt for the wires to enter, how do you terminate a PVC raceway properly in this situation?

Thanks in advance as always!
Josh
 
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Old 08-20-15, 02:01 PM
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How would the larger wire and protection be less safe, in your opinion? I'll have to let those versed in CEC stuff answer your specific question. I was just curious.
 
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Old 08-20-15, 02:29 PM
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By no means an expert here but I figured a whole spare 18 Amps before the breaker trips, might leave room for certain things to fail without tripping the breaker.

If I'm wrong I'd still be interested to hear the expert's opinions, as I'm sure he'd rather not shell out for 70ft of 6/3 if he's allowed 8/3.
 
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Old 08-20-15, 02:58 PM
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You have to install to the manufacturer's spec. What seems oversized is likely to compensate for the pump start up current.

Usually the last few feet of conduit you would switch from rigid to flexible liquidtight to go through the tub skirting and to the power box. If it is reasonably protected from damage, many areas in Canada allow TECK cable instead of individual conductors in conduit. The exterior portion of the run requires an insulated ground wire, which means NMWU and UF are not permitted, whether in conduit or not.
 
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Old 08-20-15, 03:37 PM
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So from 3/4" PVC conduit you can go straight to 3/4" Flexible Liquid Tight, with an adapter I presume?

From the breaker box to the GFCI will be indoors/under the house (crawl space), and from the GFCI to tub will be inside PVC/flex. Do we use the same wire type for both or can some money be saved for the first section?
 
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Old 08-20-15, 10:48 PM
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You haven't given us all the installation parameters.

Under the house can be 6-3 w/gr. Are you mounting a service disconnect/GFI panel on the outside of the house ? If yes..... then the 6-3 will end there and become four insulated #6 wires. So you are using two different types of wiring.

Which saves money.... you'd have to do the math. It could be less expensive to run PVC all the way to the panel and pull in four wires. If you do run PVC to the panel... upsize to 1" as 3/4" will be a tough pull with four #6's.

And yes.... you can convert from PVC to liquid tite/flex conduit.

I would run #6 wire without question but you can certainly connect it to a 40A breaker if you'd like. At least this way you could always change the breaker if you had a tripping problem.
 
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Old 08-21-15, 08:33 AM
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I understand #6 will be required from start to finish i meant which spec of insulation is required. From the breaker panel wiring will go through the floor inside, along a joist in the crawl space and terminate at a GFCI inside the crawl space. Can plain old NMD90 be used here?

And from the GFCI to the tub, will be in a raceway outside (some of it at least), I assume I can use anything listed in the CEC as for use inside a raceway in wet location? Looks like RW90 is the goto?
 
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Old 08-24-15, 09:38 AM
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You can use any wiring method that is rated for wet locations, protected from damage, and has a green insulated copper ground wire.
 
 

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