Single phase wiring

Answer 1

Simply put, a single phase supply has one or two hot wires, may have one neutral wire, and (hopefully) one ground wire. A three phase supply has three hot wires, and may (wye connection) or may not (delta connection) have a neutral. It also will have a ground wire. A more complex explanation involves the phase difference between hot wires. For three phase there is a 120 degree phase difference between each of the three possible pairs of hot conductors A-B, B-C, C-A. For single phase, since there is only one possible pair of hots, there can be no difference.

Answer 2

A single-phase, three-wire, systemdescribes a standard North American residential supply, in which the secondary winding of the supply transformer is centre tapped and earthed, providing the neutral, while opposite ends of the secondary winding provide the two line conductors. Loads connected between the line conductors are at a nominal voltage of 240 V, whereas loads connected between either line conductor and the neutral are at a nominal voltage of 120 V.

This is quite unlike the European and UK residential supply, which is considered to be a single-phase, two-wire, system ('earth' or 'ground' conductors are never included as part of the conductor count!) which comprises a line conductor and a neutral conductor having a nominal voltage of 230 V between them

Answer 3

Answer for USA, Canada and countries running a 60 Hz supply service.

Most North American residences are supplied using a single-phase 'split phase' system, which provides a combination of both 240 V (line-to-line) and 120 V (line-to-neutral).

The secondary of a single-phase distribution transformer (or one secondary phase of a delta-connected three-phase distribution transformer) consists of two 120-V windings connected in series, with their mid-point connected to ground. A neutral conductor is then connected to this point, and two line conductors are connected to the outermost terminals. This arrangement provides 240 V between the two line conductors, and 120 V between either line conductor and the neutral conductor.

Residences are then wired so that light loads (e.g. 120-V receptacles) are supplied with 120 V, while heavy loads (e.g. range ovens, water heaters, etc.) are supplied with 240 V.

Three conductors (two line conductors and the neutral conductor) enter the panel box from the pole. The neutral conductor is connected to ground at the very first panel box, and onlythere. From there, electrical codes require that the neutral and ground wires are run separately. (Older 240 V appliances "cheated" since older 240 V sockets accepted only 3 prongs, and the smallest one was intended to be ground. But such appliances added 120v lights and timers and used the ground wire for neutral. While not compliant to code, that was allowed. Since then, new 4-prong sockets have been introduced. That way, the ground can be used only as a ground, and the neutral can be used to provide 120 V to the appliance.)

For UK/European SystemsA UK/European single-phase system comprises one line conductor, a neutral conductor, and an earth conductor. The nominal line-to-neutral supply voltage is 230 V which is applied to all loads.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 4

Contains a hot, neutral and ground wire.

Answer 5

What about them!