Power Triangle

Hello every one, i just want to ask one thing....


i have one source transformer with the capacity of 50KVA, connected with two loads 10kw and second one is 15kw.. how can i calculate first load in KVA and second one in KVA ..

because Kva rating, power factor rating of of transformer is different from the load...

there must be some way to calculate load KVA rating and power factor....

Load is always in KW not KVA, as each load has its specific power factor.

KW=KVA*PF

then brother can you please tell me here which KVA we will use????

The transformer is rated in KVa as it does not care what the power factor is. The transformer usually does not give you the current rating as the MFGR does not know what the actual voltage is that you intend to use. So by giving you the KVa rating you can calculate the maximum safe current. If you do not know that Power Factor of each load then you would need to measure the curent drawn from each load. You can not assume that KW and KVA of each load as the same as the power factor will determine the current draw. Also you did not specify if this was a single phase or 3 phase system as the current calculation is different.

For single phase:
I(nominal) = rated KVA / rated Voltage

For 3 phase:
I(nominal) - rated KVA / (1.732 * rated voltage)

Under no circumstances should you exceed the nomial current - you will overheat the transformer

So for your problem you need to now either the power factor for each load or the load current.

If you add the currents- which is not the real current but only a worst case senario make sure it does not exceed the nominal current calculted above.

If you know the Power Factor then KVA = KW / PF

brother actually i saw rating of load in Kva on epcos power factor regulator which gives at first less power factor as well as has more KVA rating but when step of first capacitor turn on KVA rating or KVA demand of the load decrease and power factor increase.....
and i dont know how this regulator calculate KVA required by our load but it is true

brother i tell you all the confusion... i was working on a site on which we had very low power factor like 0.6 in winter seasons because of no load in the building for A.C and chillers..
at first system KVA was 25 means and kw was suppose 18kw so i am not sure but that time kvar was just below 10 so it could not detect by the regulator because it had first step on 20KVAr.. so utility was in loss because we had 25KVA load on the transformer and utility charging us only for 18kw.. then utility asked us to change the step rating to 10kvar and whatever the system requirements for kvar provide it from the capacitor bank and when i suddenly change the first step capacitor on 10kvar first step operate and system KVA reduce to 22kva and KW remain same but power facot increase to one.. because now whatever the system kvar requirement i am providing through the capacitor banks..
so please clear me in this formula power factor i know this is always for the load , KW is always for the load but KVA is either load or source transformer???