What's a probable VA rating for this?
That looks a lot like a variac I have:


Which is rated at 22A/3.1KVA.

The outlet box on your variac looks like it's an aftermarket add-on. If you're lucky, the info plate will still be under it.

Otherwise, the diameter of the round housing is ~7.875". If yours is the same, I'd assume it'll be fine with a 1 KW load.

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