# Does low load in transformer lead to low power factor?

Power factor is determined by the nature (resistive, inductive,
capacitive) of a load, *not* whether it is a low load or a
high load.

### Why transformer is rating kva?

Power is voltage times current times power factor. The power factor is determined by the load. As the transformer manufacturer has no idea of the power factor of the load the transformer is to supply, he can only specify the transformer's rated current and rated voltage, the product of which is apparent power, expressed in volt amperes.

### What is kva regarding a transformer?

That is the power rating of a transformer. It's given in KVA because the it's apparent power and there's no power factor because the transformer's losses are so low that they can be ignored. Answer The rating of a transformer is the product of its rated secondary voltage and its rated secondary current. The product of voltage and current (in a.c.) is measured in volt amperes. Power factor is determined by load, not the transformer…

### How much kvar capacitor bank installed for 2000 kva transformer?

It depends on the power factor of the load, but for a load power factor of 0.7 on a 2000 kVA transformer the real power and reactive power are both 1400 kilo (watts and VAR). So a 1400 kVAR capacitor on the load would restore the power factor to 1, allowing 2000 kW to be drawn instead of only 1400 kW.

### Why transformer rating in KVA not in KW?

The volt ampere is a measurement of apparent power, while the watt is a measurement of true power. Apparent power is simply the product of voltage and current; the output of a transformer, therefore, is the product of its rated secondary voltage and its rated secondary current -i.e. the apparent power of the transformer. The power supplied, in watts, is determined by the power factor of the load, so there is little point in rating…

### Why are transformers rated in KVA and not in kW?

The watt is a measure of true power, which is the product of the supply voltage, load current, and load power factor. The volt ampere is a measure of apparent power, which is the product of the supply voltage and the load current. A transformer manufacturer has no means of knowing the power factor of the load its transformer will supply. Accordingly, transformers are rated in volt amperes -the product of their rated secondary voltage…

### Why are trasformers rated in kva and not kwh?

Transformers are rated in KVA because that is a more accurate way to measure their capacity requirements. KWH is apparent power, while KVA is true power, and the ratio between them is power factor. The power factor is a function of the load, and not the transformer, so a poor power factor would make KWA look less to the transformer while, in fact, the true power, if not met by the transformer, could overload the…

### How mach load is used 100kva transformer?

i will try my best to answer this quistion, but u must not mind if i make a mistake! >>> the rating of an elctrical machine depend upon the loses in it. if, there are any losses in the machine due to power factor than the machine will b rated in KW and if there is no loss due to power factor than the machine is rated in KVA. so there are no losses in…

### What do you understand by regulation in a transformer?

Regulation of transformer means percentage reduction of transformer secondary voltage due to transformer loading as compared to its no load voltage. Another Answer A transformer's voltage regulation is defined as 'the change in its secondary voltage, from no-load to full-load, at a specified power factor, expressed as a percentage of its full-load voltage, with the primary supply voltage held constant'.

### Transformers are rated in what?

Transformers are rated in KVA. (this is because the transformer is Unity power factor device i.e.. PF = 1) Answer The selection of a transformer is determined by the apparent power of the load, expressed in volt amperes (V.A), the load current, and the line voltage of the supply. The transformer must be able to satisfy these requirements. Transformers are not 'unity power factor' devices, which is precisely why their capacity is expressed in volt…

### Why the transformer rating always mearsured in KVA only?

Well, smaller transformers are rated in VA, bigger ones in KVA, huge ones in MVA. The amps (A in KVA) are what matter the most. They generate heat and copper losses in the transformer. The manufacturer has no way to know what the power factor of the load will be, so cannot easily put a KW rating on the transformer. Suppose the transformer is rated 100 KVA. If it is supplying a kiln with a…

### What is the difference between KVA and KW of a transformer?

VA is just volts x amps. Watts takes into account Power factor such that watts = volts x amps x Power Factor. Since the Power Factor is one for a pure resistive load and decreases with inductance. Therefore a transformer rated in VA indicates maximum power rating. The K is just a multiplier of 1000.

### Why the power factor of load is not fixed on the transformer?

Because the transformer designer does not know the power factors of the different loads that might be connected to it. The way round this probem is to specify the voltage and the maximum current that the transformer can supply, then multply them together and print the VA, kVA or MVA rating on the transformer. Then it's up to the user to comply with this rating to avoid damaging the transformer.

### Why power factor lags?

Actually, it can lead or lag. Power factor is said to be leading if the load is capacitive, and lagging if the load is inductive. Since most reactive loads (like motors) are inductive, the power factor in most buildings is lagging. Additional Information... The term 'leading' or 'lagging' with regard to power factor is determined by the current waveform relative to the voltage waveform. If the current leads the voltage, then the load has a…

### Why transformers are rated in kva not in kilowatts?

KVA rating indicates the transformers maximum power output capacity. Power is power to a transformer, it does not matter if it is reactive or real, the transformer rating is based on the amount of current that is flowing through it. If it was rated in Watts you would have to factor in Power Factor which would only lower this capacity. Since this will be load dependant it is not as convenient as a rating.

### What no load power factor 3 phase transformer?

The no load power factor would tell you the ratio of losses vs. excitation current. I'm not sure that this really has any value from a performance standpoint. Answer At no load, i.e. with the secondary windings open-circuited, the primary current, Io, comprises the magnetising current, Im, which is in phase with the flux and lags the supply voltage by 90o, and an iron-loss current, Io, which is in phase with the supply voltage. As…

### Why is it desirable to have a power transformer operate at maximum efficiency when it is delivering rated load?

It is always desirable to run any equipment or device at maximum efficiency for that matter, not only the power transformer. Power transformer maximum efficiency occurs when copper loss is equal to iron loss. (or no load loss equals to load loss). This does not necessariliy mean that maximum efficiency occurs at maximum or full load. Generally the maximum efficiency occurs at relatively less than full load of the transformer.