500VA Toroid - Relay or Contactor?

[Neale]

That's a good answer to a slightly different question! No problem at all with that, if you want to switch neutral as well as live. Perfectly reasonable thing to do. What I was thinking about more, though, was the case where you are just switching live (which is what I do, and leave neutral connected). In this case, you might think of putting the contacts in parallel, to reduce the current through each contact by sharing it across all of them. However, when you switch off (probably worst case for arcing at contacts), inevitably the contacts will open at slightly different times so you will end up with one contact set, the last to open, switching the full current. I have seen suggestions that it is better to wire the contacts in series, which can reduce arcing. Some heavy-duty switchgear works like this, especially if switching DC. Anyway, it's all a bit academic if you are working within the spec of the contactor (or relay), I would hope.

[Clive S]

If you use just one contact you can use the other two for switching something else.