HVAC — Single Phase, Three Phase What's the Difference Instead, look for electrical distribution of the three phase wiring throughout the facility. To further elaborate: To operate any single phase equipment within a three phase system, all that's required is to redirect one wire from any of the three phase lines to the piece of equipment. How to Wire a 3 Phase Air Compressor - Ask the Electrician Air Compressor Electric Motor Electrical Question: How is a 3 phase air compressor wired and where do the wires go? We have a Saylor Beall air compressor we are trying to get wired up. It ran fine at the previous shop and then we moved it to this shop.