Adrian Brentnall wrote:
HI Folks
Some advice please.
I'm working on the control gear for a homebuilt glass-fusing kiln.
It's using a commercial digital controller, which provides a switched
output @ 12v DC.
Final load is two resistive wire elements, each rated @ 240v / 15A.

I can either feed the controller output through a small relay, to
provide a switched 240v AC,

Double pole relays rated at 240V/15A per pole or better will do it. Use
both poles in parallel. I made a gadget for switching the caravan
electrics automatically between two supplies using relays, and it's been
fine for 10 years.

Bill