Single phase appliance on a 3 phase panel?

Question

Can you hook up a single phase, 208 / 230V appliance to a 3 phase panel? The appliance is a RTU/Hvac compressor/condensor for a mini-split (heating/cooling) unit.

The 3 phase panel is: 3 phase, 240V Delta, High leg C

Answer 1

Yes, it's possible. In a "High/Wild Leg Delta" configuration, you have your choice of 240V or 208V. Remember always that you must use orange wire or phase tape on the "wild leg".

If you want 240V, connect between any phase and any other phase. If you have a lot of 120/240V loads on the panel, it will help phase balance to make one of the phases the wild leg (orange) (i.e. don't just pile everything onto the low phases A and B).

If you want 208V, connect between the wild leg (orange) and the neutral. This helps balance the panel.

Make sure your appliance is insulated for 208V to ground. If the appliance is only approved for 120/240V with 120V to ground, you must use phase A and B.