Three phase sockets provide three line contacts, they may also include either or both of a neutral and protective earth contact. The designations of the three contacts may vary. The IEC standards use the Line designations L1, L2 and L3. NEMA standards use the Phase designations X, Y and Z.

For three-phase, you connect line 1 to line 2 and get 208 volts. At the same time, you [can] connect line 2 to line 3 and get 208 volts. And you [can] connect line 3 to line 1 and get 208 volts.

Three-phase power is supplied by four wires. Three hot wires carrying 120 volts of electricity and one neutral. The three hot wires in a three-phase circuit are colored black, blue and red; a white wire is the neutral and a green wire is used for the ground.

It is relatively easy to use single-phase equipment in a 3-phase facility. Three-phase facilities usually have some single-phase equipment connected. The only concern is that you should try to keep the overall usage balanced among the phases.

A single phase appliance is usually fitted with a standard 13 amp plug, but can also be seen with 20 amp plus or hard wired – this means the appliance is wired into a dedicated fused switch or isolator on the wall and requires installation by an electrician. …

If the voltage is at least 200 volts for three pairs of slots, the outlet is probably a three-phase outlet. The circuit breaker must be a three-phase breaker and the voltage between three pairs of similar slots on the outlet must be greater than 200 volts.

Single-phase 220-volt AC motors are really two-phase 240-volt motors, especially when compared to three-phase 208-volt motors and single-phase 120-volt motors. This is because the motor’s single phase actually operates on the difference between the two 120-volt phases that comprise the residential 240-volt input.

It is also used to power large motors and other heavy loads. A three-wire three-phase circuit is usually more economical than an equivalent two-wire single-phase circuit at the same line to ground voltage because it uses less conductor material to transmit a given amount of electrical power.

Count the openings in the outlet. If there are three or fewer slots for plug prongs, the outlet is a single-phase outlet operating at 110 to 125 volts, or 220 to 250 volts. Three-phase outlets have at least four slots. Three of the slots each supply one phase of the three-phase electric current, while the fourth slot is the ground.

The 120-volt power outlet is the standard electrical outlet in use in homes in North America. These outlets have been in use in their present form since the early 1950s. A 120-volt outlet with built-in covers for safety.

In a loudspeaker, a phase plug, phasing plug or acoustical transformer is a mechanical interface between a speaker driver and the audience. The phase plug extends high frequency response because it guides waves outward toward the listener rather than allowing them to interact destructively near the driver.