I am installing a 4000W infrared heater in our new patio. The supply for this heater is a single phase 240V connection (rated at 16amps, so I'll use a 20amp breaker). I would like advice on two things.
Thing #1. I need the heater to run on a countdown timer, and I don't like the ugly timers that are available for 240V circuits. The switch will be in our new dining room, which will have Decora switches and outlets. So I would like to use a preset 120V fan timer that fits with the look, something like the LTB02-1LZ. Of course that is a 120V timer, so if I use that, I am wondering what relay or contactor I could use here, that has a 120V coil to switch on a 240V/20A circuit.
Thing #2. I will be mounting this on a wall, and the unit has brackets that are about 10" long to stand it off from the wall. The power supply wiring will come out of the wall, run behind one of the two brackets, and then go into the junction box on the heater. The installation instructions say:
"Junction box has a 0.86” (22mm) to a standard 1/2" weather tight conduit fittings. Install cord grip with minimum rating of IPX4 to maintain the water ingress protection rating of the heater. Cord grip must have minimum temperature rating of 90°C (194°F). Failure to install correctly will avoid the manufacturer’s warranty....For supply connections, use suitable power supply wire at least 90 ̊C (194 ̊F)."
So, specifically what does all this mean? What do I need to use in order to make the connection from the wall to the heater, and pass inspection for an exterior location? Conduit? NM-B? THHN?