What is the transformer input current if the transformer has a primary voltage of 480V a secondary voltage of 240V and an output current of 20 amps?
Transformer input current = 10A if the transformer has a primary voltage of 480V, a secondary voltage of 240V and an output current of 20 A.
How do you find the primary and secondary voltage of a transformer?
All you have to do is start by dividing the primary volts by the number of primary turns: 120 ÷ 75 = 1.6. Since you know the number of turns in the secondary, you would now multiply the 150 secondary turns by the primary current of 1.6:150 × 1.6 = 240. Now you have determined that the secondary voltage is 240 V.
How do you calculate 3 phase current of a transformer?
Three Phase Example: Using a 75 KVA Three Phase Transformer as a starting point. 75 KVA is equal to 75,000 VA. (K= 1,000) The full value in VA, 75,000 divided by 1.732 = 43,302, which is then divided by the Voltage 208V = 208.2 Amperes. This is a “Three Step Division”, technique: VA / 1.732 / Voltage = Amperage.
How do you find the secondary current of a transformer?
In other words, i1/i2 = V2/V1. For example, if the current and voltage drop through the secondary coil is 3 amps and 10 volts, and the voltage drop through the primary coil is 5 volts, then the current through the primary coil is 10/5 * 3 = 6 amps. So the secondary has less voltage and more current.
What is the secondary voltage of a transformer?
Secondary voltage is the coil winding supplying the output voltage. The output voltage of a transformer varies some with varying load resistances, even with a constant voltage input.
How do you calculate power factor?
The power factor of an AC circuit is defined as the ratio of the real power (W) consumed by a circuit to the apparent power (VA) consumed by the same circuit. This therefore gives us: Power Factor = Real Power/Apparent Power, or p.f. = W/VA.
What is the standard power factor?
Description: Power factor is the relationship (phase) of current and voltage in AC electrical distribution systems. Under ideal conditions current and voltage are “in phase” and the power factor is “100%.” If inductive loads (motors) are present, power factor less than 100% (typically 80 to 90% can occur).
What is a good power factor?
The ideal power factor is unity, or one. Anything less than one means that extra power is required to achieve the actual task at hand. All current flow causes losses both in the supply and distribution system. A load with a power factor of 1.0 results in the most efficient loading of the supply.
Can power factor be more than 1?
Since power factor is a cosine function of the relative phase angle between current and voltage there are no possible values greater than one. A power factor of one is achieved when the voltage and current are in phase and there’s no reactive power.
What causes low power factor?
The main cause of low Power factor is Inductive Load. As in pure inductive circuit, Current lags 90° from Voltage, this large difference of phase angle between current and voltage causes zero power factor.
Why is the power factor not more than unity?
Answer: Power factor is the cosine of the phase angle between voltage and current. True power may be equal to apparent power but cannot exceed. So that is why power factor can not more than unity.
How do you correct a negative power factor?
To improve negative power factor, reactive power needs to be controlled. Generally, if the power factor is lagging, then reactive power needs to be added to the load to compensate for the reactive power being supplied by the source.
How can I check my home Power Factor?
It is found by multiplying (kVA = V x A). The result is expressed as kVA units. PF expresses the ratio of true power used in a circuit to the apparent power delivered to the circuit. A 96% power factor demonstrates more efficiency than a 75% power factor.
How can we improve power factor?
Improving the PF can maximize current-carrying capacity, improve voltage to equipment, reduce power losses, and lower electric bills. The simplest way to improve power factor is to add PF correction capacitors to the electrical system. PF correction capacitors act as reactive current generators.
How can we improve leading power factor?
Power factor correction is the method to reduce the lagging power factor in inductive loads by fixing a high value capacitor across the phase and neutral close to the load. These capacitors have leading power factor so that it will neutralize the lagging power factor of the load.
Which power factor is better leading or lagging?
For inductive loads (e.g. induction motors, coils, lamps), the current lags behind the voltage, thus having a lagging power factor. For capacitive loads (Synchronous condensers, capacitor banks) , the current leads the voltage, thus having a leading power factor.
Which power factor is good leading or lagging?
Comparison Chart
| Basis for Comparison | Leading Power Factor | Lagging Power Factor |
|---|---|---|
| Value | Exists between -1 to 0. | Exists between 0 and 1. |
| Reactive component | Negative | Positive |
| Examples of respective loads | Capacitive load: Electrical motors, capacitor, radio circuits, etc. | Inductive load: Power generator, inductor, relays, etc. |
What is the effect of leading power factor?
Voltage rise by leading power factor makes eddy current loss and hysteresis loss of transformer to increase and at the same time makes capacitor for power factor improvement to get out of order and makes varieties equipments to give an electrical stress.
What is 0.8 Power Factor?
Generator sets are rated in kVA at 0.8 power factor lagging. This 0.8 power factor is not the load power factor. It is a nominal power factor used to calculate the kW output of an engine to supply the power for a particular alternator kVA output.
Do Harmonics affect power factor?
The distortion power factor term is introduced by the harmonics. A closer look at the signal will show that the current waveform is no longer a 60-hertz sine wave. The harmonics introduce high-frequency content that converts it into a double-hump pattern (see figure 2).
How do you calculate power factor leading or lagging?
If the resulting current phase angle is more positive in relation to the driving (source) voltage phase angle, then the power factor is said to be “leading”. So if the driving voltage phase angle is θ deg and the resulting current phase angle is ϕ deg. If θ > ϕ power factor is lagging. If θ < ϕ power factor is lagging.
Why current is leading in capacitor?
Leading current In circuits with primarily capacitive loads, current leads the voltage. This is true because current must first flow to the two plates of the capacitor, where charge is stored. The behavior of the voltage is thus dependent on the behavior current and on how much charge accumulates.
Do inductors lead or lag?
Pure inductive circuit: Inductor current lags inductor voltage by 90°. Pure inductive circuit, waveforms. Remember, the voltage dropped across an inductor is a reaction against the change in current through it. In a pure inductive circuit, instantaneous power may be positive or negative.
Is RC circuit leading or lagging?
If its an ac source, then the circuit is capacitive overall (since no inductor present) and so total current leads total voltage. However, on a phasor diagram, resistor voltage has same phase angle as total current ( 0∘) and hence neither leads nor lags.
Do capacitors affect current?
In effect, the current “sees” the capacitor as an open circuit. Thus, a capacitor lets more current flow as the frequency of the source voltage is increased. Capacitive reactance. As we’ve seen, AC current can flow through a circuit with a capacitance.
Do capacitors lead or lag?
When capacitors or inductors are involved in an AC circuit, the current and voltage do not peak at the same time. This leads to a positive phase for inductive circuits since current lags the voltage in an inductive circuit. The phase is negative for a capacitive circuit since the current leads the voltage.
What is lead and lag power factor?
They are determined by the sign of the phase angle between the current and voltage waveforms. The term ‘leading power factor’ is used where the load current leads the supply voltage, whereas the term ‘lagging power factor’ is used where the load current lags behind the supply voltage.
What is maximum value of power factor?
The maximum value of power factor is one. It occurs in a pure resistor circuit. As in AC circuits, the power factor is the ratio of the real power that is used to do work and the apparent power that is supplied to the circuit. So, power factor lies within a range from 0 to 1.
What is the power factor for 3 phase?
Three-Phase Power Formula This simply states that the power is the square root of three (around 1.732) multiplied by the power factor (generally between 0.85 and 1, see Resources), the current and the voltage.
How many volts is a 3 phase line?
3 phase system is expressed with line voltages. The line votage is 440 volt. Also the voltage between any one phase and neutral for a 3 phase system is 240 volts.