A transformer has separate ratings for maximum voltage and maximum current. Both limits must be observed. The maximum voltage is set by the magnetic flux density in the core, while the current limit is set by the size of the wire used in the primary and secondary windings. Multiplying the two together gives the VA or kVA rating.
Transformer power is given by P=V*I which takes the unit of KVA while that of KW has energy term which is not produced by the transformer.It only steps up or down the voltage.Answer:In a pure D.C. circuit, KW = KVA. However, in any A.C. circuit, there is real power {KW} and apparent power {KVA}, due to the voltage and current being out of phase. Power Factor is the ratio of KW to KVA. Transformers are rated in both KVA and PF. Multiplying the transformer KVA rating times the PF will yield KW.A transformer has separate ratings for maximum voltage and maximum current. Multiply the two together and that is called the VA rating, or kVA for larger transformers. So the transformer rating is independent of the power factor of the load.
Transformer rating is based on the maximum temperature a transformer can run at. This temperature is dictated by the amount of current flowing through the transformer windings. This is why transformers are rated in KVA (voltage * current), not kW - it doesn't matter what the phase relationship is between voltage and current, just the magnitude of the current.
The rating of the machine (kva or kw) depends upon the power factor, since the load power factor to which the transformer is supplying power is not known, it may be capacitive, inductive, or resistive that is why its rating is in kva not in kw.
Because its measured in kilo volt amps which is the actual reflection of current flowing through the windings. if kw were used as a rating, then it would have to be stated at some power factor
VA or KVA or MVA
The kW rating of a transformer can be calculated by multiplying the kVA rating by the power factor. For example, if the power factor is 0.8, then the kW rating of a 100 kVA transformer would be 80 kW. You can also use the formula: kW = kVA x power factor.
Transformers are rated in VA or kVA. That is because the voltage is limited by the power loss in the magnetic core, and the current is limited by the power loss in the resistance of the windings. The rated voltage times the rated current gives the transformer's rating in kVA.
kva*cos(phase angle)
Depends on the kva rating of the devices to be tested using a transformer.
Transformer power is given by P=V*I which takes the unit of KVA while that of KW has energy term which is not produced by the transformer.It only steps up or down the voltage.Answer:In a pure D.C. circuit, KW = KVA. However, in any A.C. circuit, there is real power {KW} and apparent power {KVA}, due to the voltage and current being out of phase. Power Factor is the ratio of KW to KVA. Transformers are rated in both KVA and PF. Multiplying the transformer KVA rating times the PF will yield KW.A transformer has separate ratings for maximum voltage and maximum current. Multiply the two together and that is called the VA rating, or kVA for larger transformers. So the transformer rating is independent of the power factor of the load.
Transformer rating is based on the maximum temperature a transformer can run at. This temperature is dictated by the amount of current flowing through the transformer windings. This is why transformers are rated in KVA (voltage * current), not kW - it doesn't matter what the phase relationship is between voltage and current, just the magnitude of the current.
The rating of the machine (kva or kw) depends upon the power factor, since the load power factor to which the transformer is supplying power is not known, it may be capacitive, inductive, or resistive that is why its rating is in kva not in kw.
yah! definately affects, the kva of transformer is suitable for the certain load according to the rating.
Depending upon the connected load ( R, RL, RC or RLC) with a transformer, the power goes ou from a transformer may be of two types: 1. Active Power; measured in kW 2. Reactive Power; measured in kVAR If the rating will be in kW, then kVAR rating would not be accounted but if the rating is in kVA then it is possible for us to calculate the total active and reactive current as well as the powers, at a particular system voltage!
Because its measured in kilo volt amps which is the actual reflection of current flowing through the windings. if kw were used as a rating, then it would have to be stated at some power factor
The rating of a transformer follows the two magnitudes that affect its operation; Volts and Amperes. The other, more popular parameter (kW) is not used on transformers because it depends on connected load Power Factor.
12HP is approximately 10.8 KVA. You would want to use a 15KVA transformer to supply this motor. KW = HP * .75 KVA = KW * 1.2 (These formulas are approximate)