because of its losses i.e iron and copper losses.
since iron loss depends on voltage (v)and copper loss depends on current(i).
VA or KVA or MVA
For a single-phase transformer, divide the ratedapparent power (expressed in volt amperes) by the voltage rating (expressed in volts) of the primary winding; this will give you the rated primary current (expressed in amperes) of the primary winding.
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.
the unit of generators power is KVA becoze the kva is the power that contain the active power (KW) and the reactive power mean that the name plate of any generator must contain the rated kva of it (like the transformer P (KW) = P (kva) * cos fi P (KW) = V I cos fi for single phase P (KVA) = V I when cos fi closed to 1 this will increase the useful power that exit from the generator or transformer with my pleasure
In 1600 kva transformer we provide NGR (Neutral grounding resistance)
VA or KVA or MVA
transformer action doesn't depend on power factor that is why we indicate its rating in KVA
The result is that the transformer runs cool and contented. The '250 KVA' rating on the transformer is its maximum ability to transfer power from its input to its output without overheating, NOT an amount of power always running through it. If the 3 KVA load happens to be the only thing connected to the transformer at the time, then only 3 KVA flows into the transformer from the primary line, and only 3 KVA leaves the transformer secondary.
For a single-phase transformer, divide the ratedapparent power (expressed in volt amperes) by the voltage rating (expressed in volts) of the primary winding; this will give you the rated primary current (expressed in amperes) of the primary winding.
kva k-kilo v-voltage a-amps(current)
A 100kVA transformer is rated for...100kVA. That is its' power rating, and it is based off the current that is flowing through the transformer (the I^2*R losses are the limiting factor). This can be 80kW and 60 kVARs, or 100kW and 0 kVARs, or 100kVARs, or anywhere inbetween.Another AnswerThe 'power' rating of a transformer is the product of its secondary voltage and its secondary current, expressed in volt amperes or multiples thereof. It's not expressed in watts, because to know the 'true power' of the transformer, the manufacturer will need to know the power factor of the load, and that could vary considerably. Incidentally, the symbol for kilovolt ampere is 'kV.A', not 'kVa'.
The power in a 15 MVA (15000 KVA) transformer depends on the power factor. You did not specify the power factor, so I will assume a power factor of 0.92. Simply multiply MVA by PF and you get 13.8 MW.
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.
Transformers are rated in KVA. (this is because the transformer is Unity power factor device i.e.. PF = 1)AnswerThe 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 amperes, rather than in watts.
The 3 kVA transformer will weigh double the 1.5 kVA transformer.
The kVA represents the power-handling capability of the transformer.So, if you were using a 1 kVA transformer at 110 volts, you could roughly estimate the maximum output to be 9 amps.
the unit of generators power is KVA becoze the kva is the power that contain the active power (KW) and the reactive power mean that the name plate of any generator must contain the rated kva of it (like the transformer P (KW) = P (kva) * cos fi P (KW) = V I cos fi for single phase P (KVA) = V I when cos fi closed to 1 this will increase the useful power that exit from the generator or transformer with my pleasure