Wiring – Is a double pole, double throw switch correct for the spa cover motor

If your wiring analysis is correct and the neutral is fused, this is most certainly atypical. The hot is fused to prevent a ground short from burning out the appliance and is the reason that a grounded neutral or reverse-polarized electrical plug can be dangerous. Fusing the neutral would not prevent this, which is exactly why the breaker tripped instead of the fuse blowing.

As for why it was done this way? Beats me, unless it is an error. Have you considered contacting the manufacturer? It may simply be an oversight in the U.S. wired models.

Too bad I haven't updated answer when I rewired everything - but better late, then never, right? Here are the answers to my questions:

1. White wire is neutral in US in most cases... so it was in my case.
2. Basically, two whites were neutrals for two different circuits. I bought Voltage detector and separated right white wire by turning off circuit for lights - the other white still had electricity running through it so I was able to figure it which white/neutral I needed
3. Yeah, I just cut it, add in neutral connecting from the switch and then put cap on
4. For this you need Voltage Meter, there are quite few tutorials on YouTube that explain how to figure out which wire is which with Voltage Meter.