Glad I opened my disconnect back up, the Jacuzzi installer had taken the load neutral off my breaker and put it on the equipment ground bar! I was not there when they hooked it up. (I was out working to pay for it!) I left a sealtite whip with two hots, a neutral, and a ground for them to connect to the Jacuzzi. I had re-opened the control panel on the Jacuzzi to make sure they connected it correctly on their end, but did not know they had changed the wiring on my end. The Jacuzzi did not need the neutral, so they did not connect it, but they did not insulate it either though.
Years ago I had a freind call me on a spa that had just been installed, but not heating. It was a serious double goof up on the part of the installing electricians, and the Spa installers. The electrician had installed a 30 amp 120/240 4 wire feed to the Spa, but failed to put it on a ground fault breaker. Then the Spa installers wired the whip using "Red" to the ground lug, "Black" to L1, "White" to L2, and green to "N". Needless to say this lady would have been electrocuted if she had used this Spa!