My table saw has an relay on it, controled by an on/off switch.
Today it wouldn't turn off unless I unplugged it. When I plugged it back
in, it ran immediately.

I figured either the on switch had shorted, or the relay had fused on.
The relay has 4 poles. When I move the wires to another pole, it works
fine; so I guess the relay fused.

But, I know very little about relays, so I don't know how good an idea this
is.
When a relay fuses, is it just the one pole affected and the others are
okay? If so, I should be fine until this one fuses also. Or does it damage
the whole relay, in which case I should be replacing it?

I guess the real question is, is using a different pole a reasonable thing
to do?

Thanks much.