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What is the combined load in KVA & PF?

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    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
    2.) Add KW of each load to find combined KW
    3.) Add KVAR of each load to find combined KVAR
    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

    Original thread: https://testguy.net/threads/5088-NET...estions-1-2017

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  3. driftmy240 is offline Junior Member Pro Subscriber
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    Quote Originally Posted by SecondGen View Post
    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
    2.) Add KW of each load to find combined KW
    3.) Add KVAR of each load to find combined KVAR
    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

    Original thread: https://testguy.net/threads/5088-NET...estions-1-2017
    I calculated it two different ways and got the same answer you did.
    Load 1 + Load 2 = 1,919kVA, PF=0.87

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