Calculation of TRU input KVA
Calculation of TRU input KVA
(OP)
Could someone help me work out the KVA input to a TRU using the following information?
O/P DC amps=270 @ 28VDC
Efficiency 78%
Input is 115VAC 3 phase
power factor is = or better than .97
I have done some calculations and come up with Iput Amps per phase of 17.092 and a KVA rating of 5.72, is this correct?
Thanks in advance
Paul
O/P DC amps=270 @ 28VDC
Efficiency 78%
Input is 115VAC 3 phase
power factor is = or better than .97
I have done some calculations and come up with Iput Amps per phase of 17.092 and a KVA rating of 5.72, is this correct?
Thanks in advance
Paul






RE: Calculation of TRU input KVA
270A x 28V = 7560W
Efficiency of 78% would cause the DC input to the load to increase:
7560W/0.78 = 9692W
This value at 115V 3-phase(are you sure this is correct? not 120/208V or 115/200V 3-phase? What is the actual phase-to-phase voltage?):
kVA rating is:
9692W/0.97 = 9992VA
9992VA/115V(or whatever the phase-to-phase voltage is)/1.73 = 50.2A per phase
RE: Calculation of TRU input KVA
RE: Calculation of TRU input KVA
The efficiency of the TRU is 78%
RE: Calculation of TRU input KVA
TRU? {...for the Great Unwashed.}
RE: Calculation of TRU input KVA
Your kVA rating is 9.992 or 9992 VA as stated earlier by dandale.
The line current will be 9992VA/(1.732*200V)=29A amps.
This assumes a 3 phase rectifier!
RE: Calculation of TRU input KVA
RE: Calculation of TRU input KVA
patayloruk, pardon me, but what is a TRU?
RE: Calculation of TRU input KVA
TRU
TRU stands for:
Technical Resources Unit
Teenage Research Unlimited
Test Replaceable Unit
The Real Untouchables (rap group)
Thermal Receiving Unit (M1 tank thermal sight)
Thrust Reverser Unit
Total Return Unitrust
Toys R Us
Transformer Rectifier Unit
Transitional Rehabilitation Unit
Transmit Receive Unit
Transuranic (Nuclear Waste)
Transuranic Waste
Trujillo, Peru - Trujillo (Airport Code)
Turbidity Reducing Unit
RE: Calculation of TRU input KVA
Could someone help me work out the KVA input to a TRU using the following information?
O/P DC amps=270 @ 28VDC
Efficiency 78%
Input is 115VAC 3 phase
power factor is = or better than .97
I have done some calculations and come up with Iput Amps per phase of 17.092 and a KVA rating of 5.72, is this correct?
///No, it is not since the calculated 5.72kVA are smaller than the output kVA=kW=270ADC x 28VDC = 7560W. Where would the 7560W - 5720kW= 1840kW disappear?