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# What is the combined load in KVA & PF?

1. ## What is the combined load in KVA & PF?

Two loads are connected to the same source. Load 1: 1250KVA @ 0.85PF. Load 2: 600KW, 300KVAR. What is the combined load in KVA & PF?

Another user posted 1825.8kVA @ 0.91 PF in a different thread and I couldn't come up with this answer. Here is what I did:

Find combined PF:

1.) Using individual PF, calculate KW and KVAR of each load
4.) Combined PF is calculated as:
4a.) Tan0 = Combined KVAR / Combined KW
4b.) Combined PF = Cos (TanInv0)

1a) 1,062.5kW, 658.478kVAR = 1,250,000VA @ 0.85 PF
1b) 600kW, 300kVAR = 670,820VA @ 0.8944 PF
2.) Combined kW = 1,662,500 W
3.) Combined kVAR = 958,478 VAR
4a.) Tan0 = 958,478 / 1,662,500 = 0.5765281
4b.) Cos(TanInv0.5765281) = Cos(29.9646573) = 0.8663

Find kVA using combined values and A^2 + B^2 = C^2, then sqrt(C^2):

1.) 1662.500^2 = 2763906.25
2.) 958.478^2 = 918680.076484
3.) 2763906.25 + 918680.076484 = 3682586.326484
4.) sqrt(3682586.326484) = 1,919.006

Result: 1,919kVA @ 0.87PF

Can someone check my work and let me know if I'm doing something wrong? I was able to verify my combined values using this calculator: https://www.omnicalculator.com/physics/power-factor  Reply With Quote

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Reputation  Originally Posted by SecondGen Two loads are connected to the same source. Load 1: 1250KVA @ 0.85PF. Load 2: 600KW, 300KVAR. What is the combined load in KVA & PF?

Another user posted 1825.8kVA @ 0.91 PF in a different thread and I couldn't come up with this answer. Here is what I did:

Find combined PF:

1.) Using individual PF, calculate KW and KVAR of each load
4.) Combined PF is calculated as:
4a.) Tan0 = Combined KVAR / Combined KW
4b.) Combined PF = Cos (TanInv0)

1a) 1,062.5kW, 658.478kVAR = 1,250,000VA @ 0.85 PF
1b) 600kW, 300kVAR = 670,820VA @ 0.8944 PF
2.) Combined kW = 1,662,500 W
3.) Combined kVAR = 958,478 VAR
4a.) Tan0 = 958,478 / 1,662,500 = 0.5765281
4b.) Cos(TanInv0.5765281) = Cos(29.9646573) = 0.8663

Find kVA using combined values and A^2 + B^2 = C^2, then sqrt(C^2):

1.) 1662.500^2 = 2763906.25
2.) 958.478^2 = 918680.076484
3.) 2763906.25 + 918680.076484 = 3682586.326484
4.) sqrt(3682586.326484) = 1,919.006

Result: 1,919kVA @ 0.87PF

Can someone check my work and let me know if I'm doing something wrong? I was able to verify my combined values using this calculator: https://www.omnicalculator.com/physics/power-factor

I calculated it two different ways and got the same answer you did.  Reply With Quote

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