Planning to hook up new spa with a pony or sub box as they call it, was thinking about just putting in a ground rod at the sub box for my ground and nuetral lines, that would save me from buying another 140 ft. of wire, but was reading at another site that the ground and the nuertal wire from gfci couldn't be hooked up on the same bar in the box or would trip the gfci. If I pulled all 4 wires from the main box the ground and nuetral are on the same bus bar anyway. They were saying pull all 4 wires from the main,and at the sub box bond the grounds at the sub box ,and hook gfci nuetral to nuetral bar, if the ground and the gfci nuetral were at the same bus bar then the gfci would trip. I don't understand this since in the main box the ground and nuetral wires are on the same bar anyway, so in the long run they are still connected. Can any one help I confussed??
Thanks, Gene

I'm confused too. Don't know if you have a 240 3 pole 4 wire spa with a spa box or what you have.

A low impeadace ground does not come from ground rods. It's primary purpose is lightning protection, but in case of a pool/spa 140' away it serves another purpose. It makes the exposed parts at an equal potential.

Neutrals and grounds stay separate at sub panels.

A 240 V GFCI breaker has a load neutral and a panel neutral, so it effectively has two neutral connections. One connects at the source and one is the load neutral.

GFCI protection basically comes out in the wash because when you twist L1 and L2 in the same direction with N, the currents cancel unless there happens to be a path to ground.

GFCI's also check for ground/neutral shorts after the initial connection at the GFCI in another way.

For 120 ckts, it's easy to explain: A small AC current is modulated on both the neutral and hot leads. The difference is measured directly by a transformer. If any difference is found, you have a neutral to ground short because you would not be able to modulate ground.

It's a 240 v 50amp breaker , which consists of two hots 115v. If I run both hots , the nuetral, and ground out of the main breaker but keep the ground and nuetral separate at the sub panel , then the ground and nuetral line will come back into the main breaker on the same bus bar, and this is OK, will not trip the gfci.

True.

The GFCI breaker is in the SPA panel or main panel? I'm also assuming that the SPA panel and sub-panel are one in the same.

Yes , the spa panel and the sub panel are the same, and the gfci will be installed in the sub-panel

If I just bring the two hots from the main , and put a grounding rod next to the sub-panel and connect the rod to the bus bar in the sub for nuetral and ground wires , it wouldn't be a grounded loop and work the same as if I had pulled the neutral and ground from the main, and had kept them separate in the sub. True?

Won't work. Trust me.

Thanks, I'll stick to pulling all 4 lines, from the main, and keep the ground and neutral seprate in the sub-panel, I should learn by now that my short cuts always cost me more in the long run (darn I hate to admit my wife is right). Thanks for your help.
I heard from one of my old neighbors that he yanked his meter out and connected the two hots right on the paying side of the meter. Then went to has spa box 10 feet away, so I figured the only way he hooked his spa box gfci was through a grounding rod. At his spa box.

Remember to tape the ends the correct wire colors and use conduit for a SPA.

Thanks again, keep it simple