answersLogoWhite

0


Best Answer

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.

User Avatar

Wiki User

10y ago
This answer is:
User Avatar
More answers
User Avatar

Wiki User

11y ago

transformer transforms constant power from input circuit to output circuit so there is no factorization of power.so power factor is not considered in their ratings.

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Why the power factor of load is not fixed on the transformer?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Continue Learning about Engineering

What is the condition for zero voltage regulation of a single phase transformer?

zero volatge regulation means the terminal volatge of transformer at full load on a given power factor become equal to the rated teriminal volatge of transformer , it happens only for leading power factor in transformer


What is the load of a step down transformer for 40HP?

Hi, First understand one thing seriously!! The transformer only can be rated in KVA. Bcoz, its power factor not depends on the load connected.


What is the use of transformer utilisation factor?

It tells us how much is the transformer utilised in a given process. For a rectifier,TUF =(D.c.power delivered to the load)/(power rating of transformer secondary)


Why transformer rating is called kva not kw?

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 transformer.


Why unity power factor is used in load test?

When power factor is at unity, the voltage and current waves are aligned or in phase with one another. Since power is the product of voltage and current, power transfer is maximized at unity power factor. When power is transmitted at a lower power factor, greater current is required to deliver the same amount of power. When current is increased, the size of the transmission, distribution and generation systems, all have to be increased accordingly, along with the price of the killowatt-hour at the meter.

Related questions

Why transformer power factor taken unity?

It isn't! A transformer operating at no load has a very low power factor.


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.


What condition you get negative regulation for transformer?

When its load has a leading power factor.


When is a transformer closet to unity power factor?

When it supplies a resistive load.


Why does the power factor of the load effects the V.R. of transformer?

With varying power factor the load current drawn changes, which in turn affects the voltage regulation


What is the efficiency of power transformer at same load at 0.9 lead and 0.9 lag power factor?

Same


What are common efficiencies for transformers?

Transformer utilization factor is the ration of power delivered to the load and ac rating of the transformer secondary.


Why the power factor of a transformer is poor at no load?

The inductance of the transformer is much higher than the resistance of the transformer, resulting in very low real power losses (in watts), but some reactive power (vars).


What is the condition for zero voltage regulation of a single phase transformer?

zero volatge regulation means the terminal volatge of transformer at full load on a given power factor become equal to the rated teriminal volatge of transformer , it happens only for leading power factor in 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.


What is the load of a step down transformer for 40HP?

Hi, First understand one thing seriously!! The transformer only can be rated in KVA. Bcoz, its power factor not depends on the load connected.


Why you use low power factor wattmeter on primary and unity power factor on secondary side of transformer?

There is no such thing as a 'low power-factor' wattmeter. A wattmeter always reads true power, regardless of the load's power factor.