Spa Wiring Question

[kernhills]

First off let me extend my thanks to all the folks that moderate and contribute to this board! I've done my fair share of reading as a spa newbie and have learned a ton.

I'm trying to get a qualified opinion on wire gauge for my spa installation. I purchased a 2007 La Spas Paradise H2 for $2700... What I didn't factor in to the budget was the total cost of my wiring... I expected a few hundred and am looking at $700 or so. The spa requires a dedicated 50 amp GFCI service with four wires. The total run from my main breaker box to the spa is approx. 135'. Can I use #6 to go that distance or do I need to upgrade to #4?

Also, will going with the #4 make the spa anymore efficient by decreasing electricity usage or possibly increase the speed that it heats?

If I can go #6, this is the wire I'm looking to purchase. http://www.globalindustrial.com/p/electrical/wire-cable/wire/thhn-6-gauge-building-wire-stranded-type-orange

Thanks again!!

[Mikey_in_NY]

#6 wire is common for a 50A hook-up, however a run of 135 feet is definitely on the long side, so you may(?) need to go to #4 wire. Suggest you speak to a qualified electrician, or wait for a more knowledgeable forum member than myself to advise.

Assuming the correct wire is being used there is no advantage to going to a bigger one.

[bfunke]

US National electric code specifies 6ga CU for 240V 50A 1 phase AC with 135 foot run length. Are you planning any other loads on the circuit? Is so you may want to go larger and wire a subpanel. Are you planning conduit or Romex run? You'll want to be careful not to create a dangerous overheat situation by mismatching wire applications.

[hot_water]

If it's just the 4 wires for the spa, #6 should be fine for 50 amps. The wire you're planning to use needs to be installed in conduit, which can be buried or installed above ground (check with your local electrical inspector for burial depths of the various conduit types).

What you should understand is that the wire size depends on the ambient temperature and the number of conductors in the conduit. The standard is figured at ambient temps of 86F, and for three current carrying conductors (the green equipment ground doesn't count). If you run other electrical circuits in the same conduit, it derates the amp capacity ("ampacity") of the wire. So if your installation will see higher temps, or if you're putting other conductors in the conduit, you could need to upsize. It's a good idea to pull a permit if your area requires it (most do), just to insure that in the event of any future problems your homeowner's insurance won't point to unpermitted work and disallow any claims.

No, you won't see any operational difference by going to #4. The voltage drop in a #6 at this length at 50A is a percent or two, not enough to worry about.

[olympic]

The timing of your question kernhills was perfect. I've been lurking and my situation is almost identical to yours. We are purchasing a new hot tub that requires a dedicated 50amp circuit. My distance is 140 feet from my panel to the spa disconnect. There will then be about another 20 feet from the disconnect panel over to the spa itself.

I was looking for confirmation on a few items. I don't want to hijack this thread, but am thinking the same types of issues may be present for both of us since our distances are within 5' of one another:

1) Looking for confirmation that #6 gauge wire is the right wire for the 50amp circuit for the distance: (4 wires) pulled through 1 1/2" conduit, buried 18" deep and running a total distance of 140' from panel to spa disconnect

2) Do I need to use #8 or #6 gauge wire from the spa disconnect to the spa itself?

3) Looking for confirmation that breaker in panel should be 50amp.

4) Looking for confirmation that GFCI breaker in disconnect can be 50amp or 60amp.

Thanks in advance to anyone that can confirm the above. I don't want to have to do it again with the price of wire these days. :-)

[7808]

i ran three #6 stranded and one #10 solid for ground if that helps/saves some $$ i see alot of #6-3 wire (3x stranded #6 and one #10 solid for ground) bundled that way so dont take my advice but figured it was ok. i already had 240 to my garage for a outlet just put a 125a load center there instead saved me probly 50ft on the wiring run

[njmurvin]

The timing of your question kernhills was perfect. I've been lurking and my situation is almost identical to yours. We are purchasing a new hot tub that requires a dedicated 50amp circuit. My distance is 140 feet from my panel to the spa disconnect. There will then be about another 20 feet from the disconnect panel over to the spa itself.

I was looking for confirmation on a few items. I don't want to hijack this thread, but am thinking the same types of issues may be present for both of us since our distances are within 5' of one another:

1) Looking for confirmation that #6 gauge wire is the right wire for the 50amp circuit for the distance: (4 wires) pulled through 1 1/2" conduit, buried 18" deep and running a total distance of 140' from panel to spa disconnect

2) Do I need to use #8 or #6 gauge wire from the spa disconnect to the spa itself?

3) Looking for confirmation that breaker in panel should be 50amp.

4) Looking for confirmation that GFCI breaker in disconnect can be 50amp or 60amp.

Thanks in advance to anyone that can confirm the above. I don't want to have to do it again with the price of wire these days. :-)

Personally, I'd run #6 all the way (which is what I did). How much do you really save in that 20' by downsizing? My spa calls for 50amp. So, I have a 50amp breaker in the main panel and a 50amp GFCI in the disconnect. BTW, the best deal I could find on that disconnect is from Home Depot ($50 or so as I recall).