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.
KW is multiplication of KVA and power factor. Power factor is load dependent and varies as per the type of load. Hence the rating or capacity is mentioned in KVA not in KW
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.
Rating for DG set and any of electrical machines is calculated in KVA. KVA is calculated as KW/pf. One can calculate the required KVA for DG set with this formulation: (KW/pf)/load rate. For example KW=110, pf=0.8 and one loads the DG at 75%, so KVA= (110/0.8)/0.75=185 KVA.
5kw = 6.25 kva becoz kva = kw/ pf if we take pf is o.8
No; drawing more than the rated amperage from a transformer will cause it to overheat.
Inverters and generators are not rated in BTU's (British Thermal Units). They are rated in KVA (Kilovolt amps) and KW's (Kilowatts). These two values are the product of amps times volts. KVA times PF (Power Factor) = KW.
KW is multiplication of KVA and power factor. Power factor is load dependent and varies as per the type of load. Hence the rating or capacity is mentioned in KVA not in KW
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
One reason is that the motor is expected to do work (watts) whereas a transformer only changes the voltage and (ideally) does no work. [Yes, losses do occur.]
Transformers are rated in KVA which is equivelant to "apparent power". Loads, {such as heaters, lamps, etc.} are rated in KW which is equivelant to "real power". Things such as power factor and transformer efficiency account for the diifference between the two values. KW's are what the load requires and KVA's are the values of the input power required in order to serve a given KW load. Unfortunately the utilities charge for KVA not KW. It's not too unlike a glass of beer. The enjoyable part is the beer itself. However, you pay for both the beer and the foam at the top of the glass.
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.
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 a transformer due to power factor so it is rated in KVA. as the KW= KVA* power factor so, kVA= KW/power factor here, KVA=100 so, KW= 100*power factor u can derive from here that the load on a transformer depends upon the power factor. as the power is always less than unity so the load will be less than 100KW. thankyou!
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.
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)
Transformers, like inductors can only handle a specific amount of voltage and current before overheating, with AC or DC input. AC 'real' power delivery from a transformer is measured in kilowatts (kW) which is identical to KVA when "Power factor = 1". In the extreme, with "Power factor =0", a transformer could be fully loaded in terms of KVA, while supply zero 'real' power (kW).
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.
You can't determine the output voltage of a transformer by knowing kva. Transformers will be marked as to input and output voltages. Some will have multiple input and output voltages. The output voltage depends on the ratio of coil turns between input and output.
KVA means thousands (K) of volts (V) times Amperes (A). A 100 KVA transformer can deliver 1000 amps at 100 volts or 500 amps at 200 volts etc.