What are formula we can apply to determine the HT/LT current of 11KV/433V transformer except KVA/LV×√3. ?

Answer Posted / pradyumna171

Fourmela No 1 power in one phase/Voltage in one phase(I.e phase voltage)
example there is a 300 KVA 11KV/433 V transfomula. Power in one phase 300KVA/3 =100KVA both in HT & LT side, Phase voltase in HT side 11/√3 = 6351Volt .Phase voltage in LT side 433/√3 = 250 Volt.
According to formula HT side current 100,000/6351 = 15. 7 amps. and LT side current 100,000/250 = 400 amps
Formula No 2 for HT side transformer in kVA/20 and for LT side KVA×4/3. field lineman are using this formula.
According to this formula 300 KVA transformer's HT side current 300/20 =15 amps apporximately +5℅ may added for big size to accurate value. And LT side current 300×4/3 = 400 amps apprx.
In general formula for 300 KVA 11KV/433V transformer HT side current KVA/LV×√3 i.e 300000/11000×1.732 = 15.7 amps .LT side current 300000/433×√3 = 400 amps

PRADYUMNA CHANDRA PANDA
mob No 943
7917849

Is This Answer Correct ?    4 Yes 6 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

How to select the gauge of wire for winding of motors? How to select number of turns for winding of three phase induction motor?

2245


volts=230 c=10mf a=??

1587


How to design inductive load for 3 phase 440v and maximum 5 amps for star or delta? Can we use a 15kW, 1450rpm motor for 15kW, 960rpm apllication?If yes.how......n.if thesame motor used what`s it`s sideeefect.

2050


What is a single phase autotransformer?

647


Define what is power quality meter ?

670






what is the difference between elcb and rccb ?

1784


What is the tests required for a 132 kV, 400 kV , 765 kV for a Circuit Breaker and Power Transformer before commissioning ?

1172


How to check the thermocouple is correctly connected to cable for K type? (i,e positive pole is connected to non magnetic conductor and negative pole is connected to magnetic conductor)

1259


Define step response?

652


why 15 kw motor winding resistance is low then 5 kw motor winding resistance?

2394


what is the meaning of impedance protected in instrument cooling fan

2804


What is the difference between electronic regulator and ordinary rheostat regulator for fans?

576


why servomotor motor? where i apply for best output?

1560


Why reactive power is needed in a power system? How is it being absorbed or delivered by alternators? For reactive power control we are changing excitation but reactive power absorbing or delivering related to stator. How these two are interlinked? i want a detailed explanation with necessary expressions and figures?

1406


How do you calculate the actual power consumption of an inductive load appliance. Say, a deep freezer of 200watts

1660