The picture doesn't show it well, but it's there. The black (hot) wire is going into L1. L2 and neutral are jumpered together with the orange wire since this is a 110V hook-up.

Did you test your gfci operation by using the wiggy between L1 and Ground inside the 1400 box... (at the position I indicated above)?

This is crucial. Testing at the outlet won't tell us what we need to know.

I wouldn't be suprised to find that in one of your gfci wiring things, L1 and Neutral were reversed. That's why we need to test L1 to ground AT the controller box. If it doesn't trip the GFI, then shut this thing down right away and investigate...

I've seen this bizzar thing happen that shocking can be caused by another appliance with a bad ground... such as an airconditioner unit etc located near by... Just thought I'd mention it as its conceivable the spa MAY not be the culprit...

BARB

I tested from L1 to N and it did not trip the GFI, but then thinking about it, I realized it probably shouldn't it's in circuit. I then tested from L1 to the grounding rod I installed next to the hot tub and it tripped the GFI right away. This is the same grounding rod I've actually had sitting in the water trying to see if it would trip the GFI. I also purchased a better meter which measures current and has a data log holder to measure peak voltages/amps. All I could get was a max of 170mv and no current, not even ma's. Maybe I'm just being paranoid as hell here, but I tell you, when you put your hand in the water and are standing bare foot on wet cement, you can feel a shock.

As for other appliances nearby, the hot tub is about 20 feet from my house. I had to run a 50' extension cord to it from the GFI outlet I installed on the outside of the house. The GFI outlet goes to a dedicated breaker which is only being used for this one outlet, which has nothing else plugged into it. I do have a pond pump within 20 feet of the hot tub, it too is on a GFI circuit (different one). I will try disconnecting it at some point and see if the problem goes away. I would think I would notice on my electric bill if the pump were leaking that much current to ground though.

I'm still completely clueless. This may sound really far fetched, but I wonder if I'm not getting power coming off the main power feed to my house (it runs through a tree) going down the tree into the ground and effecting an area of say 100' or so. In short making the ground hot while the water is earth ground. I'm just not sure how to test for this.

OK, I finally have found something that begins to make sense. I am able to consistently get 20VAC from anything the hot tub is sitting on to earth ground. I have the hot tub sitting on a wooden platform which is sitting on a concrete slab. If I measure the voltage from the wet concrete to earth ground I get 20VAC. I can also get 20VAC from any nail in the wooden platform to earth ground. This is consistent as long as the hot tub is plugged in. If I remove power, no 20VAC. So much for my discovery of free energy! I have unplugged all external devices (blower, pump, etc) and the problem is the same. Is also remains if the heater box is off (power switch). What runs off of 20VAC in a hot tub? I figure the light must be close, but the light is turned off and I still have the problem. The outside case of the heater box is earth ground and I have a separte bonding wire connected to it to make sure.

Did you test inside the box, from L1 to GROUND inside the 1400 box?

L1 to the ground terminal right next to the Neutral.... Not the grounding rod outside the tub, and not L1 to Neutral.

L1 to Ground inside the 1400 Box

While you're at it... what's the grounding rod connected to? Anything besides sitting in the water?

I'll requote my previous post:

OK, I finally understood what you were asking me to do. I tested from L1 to ground (green wire) and it tripped the GFCI. I was confused because Neutral is earth ground in every respect I can measure. I don't understand how ground can be different from neutral--this is an area where my electronics theory breaks down.

As for the grounding rod, it really depends which one you are asking about. I installed a separate grounding rod next to the hot tub for extra safety after having this problem. If you are refering to that grounding rod, it is normally connected to the bonding lug on the heater box. I have taken it and put it straight in the water (not touching anything but the water and shell) in an attempt to see if would trip the GFCI--it never did. Now that I better understand the nature of the problem, I see why it doesn't. The water is earth ground and the grounding rod is earth ground. My problem seems to be voltage is leaking from somewhere into the hot tub base even into the surrounding concrete. It's still a very strange problem and I have no idea where to look for what is causing the voltage leak. I know it is isolated to a problem with the AP-1400 heater box because I've had everything else out of circuit, but the AP-1400 is grounded two different ways and measures no voltage from the outer case to ground. This is why I have no idea where my voltage leak is coming from.

Now, since you've absolutely and positively verified that L1 to ground inside the pack trips the GFCI, then the problem is definitely not with the spa.

Now this one will suprise you....

With the GFCI tripped, you should still see loose voltage laying around, and still get that darned shock. Unplug the spa, and it'll go away.

What's happening is that the plug-in to the house is giving a electrically perfect ground return to whatever voltage is on the surface of the ground. You do have some kind of problem here. I'd unplug everything outside and do the checks again. If no luck, I'd be calling the power company. See Barbara's post above.

Your theory that ground and neutral are electrically identical is correct, but what the GFCI's job is, is to monitor L1, and Neutral only. If anything leaves L1, doesn't come back into neutral directly, (as in ground), then it'll trip the breaker offline. The GFCI doesn't monitor ground as it could care less what ground is! Matter of fact, it only knows that what leaves one terminal must match milliamp for milliamp what comes back to it on the other. If it's imbalanced, then it trips.