Will three phase power damage single phase appliances?

Answer 1

If you plug a single phase appliance into a three phase power supply, then you will be using single phase power. It does not matter if you are delta connected, AB, BC, or CA, or if you are wye connected, AN, BN, or CN. Yes, if there was "a problem", you would trip the supply. Question, however, is what do you define as "a problem"? Three phase power is intended to supply three phase appliances. Connecting a single phase appliance to three phase power is inconsistent with the objective, and such connection must have been performed by some kind of "jury-rigging". If you pull more than the trip current on any one phase, the supply should trip. If a malfunction in the single phase application, however, were to result in fault current that is lower than the trip current, you might not trip, and you might create damage and/or a fire. There is nothing wrong with building a branch circuit that feed a single phase load from one phase of a three phase source. You just need to provide the correct protection for that intended load.

Answer 2

This is generally fine, as long as you connect the hot wire to one of the three phases and the neutral wire to the neutral. Note that there is one caveat for this for some older three phase wiring in the US. The voltage between the the hot wire and the neutral will be 115 volts for only *two* of the three phases, on the third phase the voltage will be 170 volts (if memory serves me correctly). Make sure you connect your equipment to one of the 115 volt legs and not the 170 volt one or you will damage your equipment (as in you will see smoke coming out of it type of damage). Whatever you do make sure you do not connect your equipment across two of the hot legs (phases) or you will see even more smoke than connecting it to the wrong phase.

Answer 3

Yes and no. You can only connect the single phase appliance to one of the lines of the three phase power. If the voltage and current match, then the appliance will work correctly. If not, then damage could occur.

Another Answer

Not if you connect the load correctly, and the voltage applied to the load matches its voltage rating.

For a three-phase, three-wire, system, you can connect a single-phase load across any two line conductors. For a three-phase, four-wire, system, you can connect a single-phase load across any two line conductors, or between any one line conductor and the neutral conductor. In each case, of course, the voltage obtained must match the voltage requirements of the single-phase load.

Answer 4

The power supply to a given piece of equipment is governed by what the manufacturer requests, to make the equipment operational. By applying the wrong phasing or voltage will usually not allow the equipment to operate the way the manufacturer intended it to. Single phase systems has its uses in supplying services to homes whereas three phase systems are used in commercial and industrial services.

Answer 5

Not for the appliance but maybe for the grid.