Electrical Engineering

The armature is the moving part of a motor or generator.

Tthe shaft is the central rod on which the armature rotates.

The commutator is the part that transfers the power too or from the moving windings in the armature to the static part of the motor or generator (either too or from the electricity supply).

The same as in single phase with the same RMS voltage.

Armature reaction is effect of armature flux on main field flux.

Basically there are two windings in a dc motor - Armature winding (on stator) and field winding (on rotor). When we excite the field winding, it produces a flux which links with the armature. This causes an emf and hence a current in the armature. This current in armature produces another flux which lags the main flux. This is referred to as armature reaction. It has two effects on the machine:

1. Demagnetising effect: It reduces the strength of the main flux.

2. Crossmagnetising effect: Its effect is that it bends/distortes the the main flux line along the conductor

An isolator is just a disconnector ; it disconnects the load from the supply. The method of operating the isolator can be through a handle or through a spring or through a motor. Isolators can be on-load isolators , which can be switched off on load , or they can be off-load isolators which should not be switched off on load.

A Miniature Circuit Breaker can break or open in the event of a fault. Thus its load carrying capacity is extremely high , up to 10 kiloamperes or more.

What this means is that if a short circuit current to the tune of 10 kA flows through an isolator , it will melt the isolator contacts , and the damage can be irrepairable. When the same current flows through an MCB , the breaker will trip , without suffering any permanent damage. Thus an MCB is a protective device.

improved communication

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The "current choking" means that the maximum capacity of a transformer is not being utilized. To prevent it from ever reaching its maximum capacity a lower value of over current protection or fuse is installed. The purpose is to use larger capacity transformer available but using smaller distribution and cables just sufficient for the application to lower the installation cost.

A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled wires. A changing current in the first circuit (the primary) creates a changing magnetic field; in turn, this magnetic field induces a changing voltage in the second circuit (the secondary). By adding a load to the secondary circuit, one can make current flow in the transformer, thus transferring energy from one circuit to the other.

A choke is an inductor designed to have a high reactance to a particular frequency when used in a signal-carrying circuit.

An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit.

Ballasts vary greatly in complexity. They can be as simple as a series resistor as commonly used with small neon lamps. For higher-power installations, too much energy would be wasted in a resistive ballast, so alternatives are used that depend upon the reactance of inductors, capacitors, or both. Finally, ballasts can be as complex as the computerized, remote-controlled electronic ballasts used with fluorescent lamps.

The transmission lines which have length less than 80 km are generally referred as short transmission lines. For short length, the shunt capacitance of this type of line is neglected and other parameters like electrical resistance and inductor of these short lines are lumped.

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When they are in parallel the same voltage appear across both. The resistor carries a current of V/R, the inductor carries a current of V/(jwL). So the current in the inductor is 90 degrees behind in its phase.

Transformers are not necessarily centre tapped, although some are. In North America, for example, the secondary-side (240-V) of a distribution transformer is indeed centre tapped. It is at this point which it is earthed (grounded) to provide the neutral conductor to a residence's supply. The outer ends of the winding are then at 120 V with respect to that neutral -thus providing the residence with a combination of 230 V and 120 V. Lighting and (120-V) receptacles are then connected between one or other of the outer terminals and the earth terminal, while (240-V) heavy appliances are connected between the outer terminals. European distribution transformers are not connected in this way; they do not have a centre tap secondary.

Assuming you can get a three-phase 230 v supply, which has 133 v between neutral and each live, the full-load current assuming a 30% increase for power-factor and efficiency considerations would be 120 amps.

In Europe the standard three-phase supply is 400 v. In the US three-phase supplies are normally 208 v or 480 v and an alternative option is a 240/480 v split-phase (single-phase) supply.

In very simple terms, if the voltage output of the device being paralleled is lower than that of the device already on line, then energy will flow back to the device being paralleled. In practise, it can be far rather more complicated than that: for example an alternator connected to the grid can have the same voltage as the grid, but if insufficient torque is applied to its rotor, then energy can flow back to the alternator, causing it to 'motor'.

Lapp is the name of the manufacturer, but this is a 3-wire cable with conductors of 4 sq. mm. in size.

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Shorting the motor's electrical supply will blow the fuse and the motor will run down and stop.

A breather is used for underwater breathing in the Transformers Franchise. Most transformers have this feature, however, there are some who don't, like Pptimus Orime, Negatrom and more.

It should do so easily; 1.5 HP is only about 1100 watts, which is significantly less than 3.5 kVA.

No. But bear in mind that, in the case of a.c. circuits, 'total', means the phasor (vectorial) sum of the voltage drops, NOT the algebraic sum.

One reason an electric motor might lock up is if the bearings seize or freeze (not meaning "freeze" from cold weather but "freeze" as in "lock up" and be unable to function).

Welding is done with a high current and low voltage. The voltage of a 500 amp welder might be 10 v so the power rating in that case would be 5000 watts.

If that's y to the zero power, the value is 8.

A 1-ton AC can melt a ton of ice in 24 hours. The power needed is theoretically 3517 Watts so allowing for power factor and efficiency you would need a 7 kVA generator.