Are single phase 208v and single phase 230v equivalent?

Answer 1

No, not really. 208V is derived from two phases of a 208/120 three phase power system, while 230V (or 240) is a single-phase power system already. Motors and other loads are usually notrated for both voltages, and could be damaged if fed the wrong one. Of course, other devices are rated for both. If so, it will be listed on the nameplate.

Answer 2

208 is a not a single phase voltage, it is a line-to-line voltage used in three phase power. The line to neutral voltage of 208v is 120volts, with the L-N 120 volts 120 degrees out of phase with each other.

220 (or 240) is a single phase voltage where the neutral point is physically the "center" of the step down transformer, so you get two 110 (or 120) voltages 180 degrees (opposite) each other.

So, yes it is the same, if used at 120 volts, and you don't have an intermixing of the two incoming 120 volts (they will be out of phase = bad things happen). No, if you want to connect 220/240 volt equipment - you will still only get 208. The way the 208 is grounded might cause you issues as well.

If this is not purely an academic question, I would recommend discussing your purpose with your local power company to determine what's best in your situation.

Answer 3

You have it around the wrong way. 120 volts is from a three phase 208 voltage system. 208 divided by the root of 3 (1.73) equals 120 volts. A 208 voltage distribution system is a wye connection that has its center point tied together and grounded. Any three legs of the wye configuration to the grounded center point will give you 120 volts. Any two legs of a three phase system are classed as single phase in the electrical trade. L1 - L2 = 208 volts, L2 - L3 = 208 volts and L3 - L1 = 208 volts.

The 120/240 distribution is a single phase system. It is the secondary side of a step down transformer that the utility company uses to supply electricity to homes in North America. The output of the transformer is 240 volts that has a splice tap in its center of its winding. L1 - N = 120 volts, N - L2 = 120 volts. L1 to L2 = 240 volts.

Now back to the question as long as the equipment states that you can use it on the dual voltages of 208 to 240 volts the equipment will work.

Answer 4

Yes, 120 volts is single phase, being one leg to ground (neutral) of a 208 volt three phase wye connected distribution system. These connection are used in apartment buildings in North America. The service is stated as 120/208 volts. The 120 volts is derived from the three phase leg to leg voltage, 208/1.73 = 120 volts.