Hi- Been lurking for awhile and have found this to be the best spa site yet! Great info that really helped me with my spa research. Got an 05 Sundance Optima -240 v- and set into my deck and my electrician gave me a stock list. He said to get a 50 A GFCI for the main panel, a disconnect for near the spa, and 75 ft of 6-3 NM. We'll run the wire to beasement wall, drill through the sill, go up to the disconnect, then he wants to just run PVC conduit under the elevated deck and drop down to the tub. I read the owners manual and Sundance only requires 3 wires- red,black, and ground. If I'm putting the GFCI in the main panel, can't I use 6-2 wire? He said he needs all 4 wires going to the tub, but I think it's becasue he's only done 4 wire tubs before. There's a big price difference in my parts between 6-2 and 6-3. Also, do I need outdoor UF wire if it's going to be in conduit outside? That's a big price difference as well. Also, my house feed has 3 wires- red, black, and ground, and my panel only has one neutral bar, not a seperate ground and neutral. All the whites and bare wires are clamped onto this bar. Do I need a specific GFCI for this?

Second question- is it OK to run 1" PVC conduit under the deck for 7-8 feet? I was going to dig a trench, but he said not to worry, under the deck was fine. What do you think? Thanks in advance for the responses!
-Dan

Check with your sundance dealer first to determine if you require a 3 or 4 wire hookup, the manuals are generic and may not apply to your particular set-up. If your spa does only require 2 wire + ground then you need to remember that for most GFCI disconnects to work properly you need to run a 4th wire to the disconnect from the main panel and then simply not run it to the spa. Hope this helps.

Toptech- I'm putting the GFCI breaker in the main panel.....so I should be able to get away with 6-2 wire to the disconnect (no GFCI there) then onto the spa.? And the Sundance Optima is a 3 wire hookup and not 4 wire,Hence the title of my post. Did my homework on that before I posted...... Thansk for taking the time to reply...this has been bugging me.

Yes, 2 wire + Ground should be fine at that point.