Electrical Wiring

The current is the same in the three live wires. The voltage can be described as the line voltage (phase to neutral) or the phase voltage (phase to phase) which is larger by a factor of sqrt(3).

So a line voltage of 230 v corresponds to a phase voltage of 400 v.

The formula you are looking for is 460 divided by the square root of 3 (1.73).

The cable size depends on a few factors, such as the supply voltage, the method of starting the motor, (direct-on-line, or star delta) and the length of cable required to compensate for voltage drop. Also, if the cable is copper or aluminum.
110 kW motor has a rated current of 200 amps at 415 volts, so the correct copper cable size would have a cross-sectional area of 75 square mm., if the motor is started direct-on-line.
At 660 volts, the rated current would be 118 volts and the cable size would be 35 square mm.

The motor will run, but it will turn slower than the nameplate rating, it will draw more current, it will run hotter than it would have on 60Hz, and it will not ouput the full rated horsepower. Depending on the application and how hard the motor is actually loaded, you might be able to get away with it, but usually not. 220V 60 Hz motors are rare. It is more likely a 208V, 230V or 240V motor. Some motors are actually dual-rated for both 50 and 60 Hz, with corresponding different speed and Amp ratings. Check the nameplate!

ONE THING FOR SURE THERE IS NO CHANGE IN VOLTAGE IF SAME EQUIPMENT WE ARE TALKING ABOUT. THE ISSUE HERE IS THE CHANGING LOAD FREQUENCY 60HZ TO 50HZ OR VICE VERSA. FOR EXAMPLE THE MOTOR HORSEPOWER AND R.P.M. WILL BE APPROXIMATELY 90 AND 83 PERCENT OF THE NAMEPLATE SPECIFICATIONS, ALSO THE FULL LOAD RUNNING TORQUE WILL INCREASE APPROXIMATELY 8 PERCENT IF USED FROM 60HZ TO 50HZ.

It is a type of transmission where you can shift forwards to backwards or the other way around with out having to come to a complete like normal tractors have to.

For comparing cost copper requirement is necessary

copper in 3 phase = .75(copper in single phase)

i.e. less cost in 3 phase when

1. line voltage is same

2. equal power input

3 same power loss

When the phase voltage is same & 2,3 conditions met then equal cost.

Armored electrical cable contains insulated electrical service wires protected by a flexible steel covering. Unarmored electrical cable has no protective flexible steel covering, its covering is made of plastic.

<><><>

Armored cable (BX) is the older version of Metal Clad cable (MC). It was flexible steel covered wire that used the steel as it's Ground. BX was a poor grounding system so it was replaced with MC which looks similar but has a separate Grounding conductor. MC is most often made with aluminum as its cover.

Armored cable if used today will refer to MC type wiring.

<><><>

Some kinds of armored cable are in fact made to a tougher standard than the ordinary soft wire strand types of shielded cable that are used for hooking-up antennas. The 'armor' is actually a thin flexible metal film that better protects the wire or wires inside from damage in high use or high traffic areas. Such kinds of armored cable are also used in radio frequency assemblies in electronic equipment.

The speed of an electric motor is directly proportional to the frequency of supply. The rpm written on the name plate is the maximum operating speed for the motor design. Typically, for a squirrel cage induction motors, the speed is constant by design and this type of motor cannot operate for a long time at speeds below the rated value.

It is true that loading affects motor speed to some extend but the electric motor will accelerate to the rated speed. If the loading is within the design parameters of the motor, the electric motor speed will not drop.

What typically happens is that if the loading increases, the speed goes down, and the current increases. Because voltage is constant, this result in a high I2R loss in the windings and the motor circuit protection trips on thermal and electrical overload.

The formula for electric motor speed is SRPM=(120f)/P.

The above is for AC motors. If you are referring to a DC motor, what you have stated is correct. The motor will slow down as load is added. That is why you are not supposed to run many DC motors under no load conditions - they will overspeed.

25 amps

is the measured voltage,generated between a line voltage and the starting point of a three phase transformer, which is the neutral point.

Answer: it is an ac circuit in which the supply has a live and neutral wire, usually at one of the standard voltages 110/120v or 220/240 v. A three-phase circuit is a combination of three single-phase circuits with the phases of the voltages 120 degrees apart so that they peak in a regular sequence.

Single phase power can be taken from a three phase system.

Any two legs of the three phase system, taken together, are considered to be single phase. The legs can be any of the following combinations, L1 - L2, L2 - L3 and L3 - L1. On a three phase four wire system, called a wye connection, any line to the grounded neutral is also considered single phase. L1 - N, L2 - N and L3 - N.

Unit is volt. So it is joule/coulomb

Now joule has dimension M L2 T -2

For coulomb the dimension will be A T

So dimension for electromotive force = M L2 A -1 T -3

F

Power= current*voltage

First convert 250 hp into watts (about 186425 W)

Divide power that by the voltage, and you get about 388.38 amps.

You may want to double check my unit conversions.

Reducing core losses is a design responsibility of the manufacturer. They do this by laminating the core (to reduce eddy-current losses) and carefully selecting the type of material used for the core (to reduce hysteresis losses). There's very little that you, as the user, can do about reducing core losses.

Wood, oil, coal and gas can all be burned in power stations to heat up water. The water boils and turns to steam, driving a turbine, which turns a generator, producing electricity.

A nuclear power plant is the same, except the nuclear reaction is used to heat the water.

To answer this question the voltage of the motor must be stated.

The secondary of a transformer is isolated (floating) relative to the primary, so there is no absolute reference relative to earth ground on the secondary side. By connecting the neutral to ground (earth ground that is) this creates an absolute reference. This also creates a leakage path to earth ground, now that the secondary voltage is referenced to earth ground, but that is more desirable than not because otherwise something else in the system might improperly provide that reference.

The big difference is that the synchronous motor's rotor can have a variable current applied to it through its field slip rings. Both types of motors have their own advantages. With a synchronous motor in the system, the systems power factor can be regulated.

1 Kilowatt is the same as 1000 Watts. The answer depends on two (actually three) things. What is the supply voltage, is the power source single or 3-phase, and is the load reactive (like a motor) or resistive (like a heating element or incandescent lamp)? For single-phase power feeding a resistive load: Amps = Watts / Volts Example: 1KW 120V baseboard heater: 1000W / 120V = 8.3A If the load is reactive, then you must take power factor into consideration. VA (Volt-Amperes) = Watts / PF (power factor) Amps = VA / Volts Example: A 240V motor that draws 3KW and has a PF of 0.83: 3000W / 0.83PF = 3615VA 3615VA / 240V = 15.06A The formulae for 3-phase power is exactly the same except you must divide the answer by 1.73. For instance, our 240V motor, if it were 240V 3-phase (for the sake of discussion) would be: 15.06 / 1.73 = 8.71A As you can see, power factor makes a big difference. VA is called "apparent power" because it's what you appear to have if you take measurements with a voltmeter and ammeter and do the calculations. Watts is called "true power", this is what you, the typical residential customer, pay the utility company for. Oh yeah, sometimes you will see PF expressed as a percentage. In our above example with PF = 0.83, you might find either 0.83 OR83% on the motor nameplate. If you run across the percentage figure, mentally convert it to the decimal number before using it in the formula.

Some commercial grills have the ability to be wired up single or three phase. Find the grille's nameplate and see if it can be done. This job is best done by an electrician as resistance coil ends have to be found and series or paralleled together depending on what the voltage is. I have done this once on an electric kiln and it took about an hour. To save you electrician costs have the manual of the grill ready so that the connection can be determined right away.

If you are looking for total load just add the loads together. If you are looking for sizing of a service to feed the loads, factoring is brought into the equation and it is governed by rules in the electrical code.