Anonymous asked in Science & MathematicsEngineering · 1 decade ago

how could i calculate the capacitor rating for correcting the pf of my factory?

my company has a 150kw total load

3 Answers

  • 1 decade ago
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    If you know the kW, then you need to measure the kVA load of the factory. Measure the incoming voltage and current when the highest load is occurring.

    For 3-phase service, average the voltages and the currents.

    Volts x Amps x √3 x 1000 = kVA.

    You also need to know how much you want to improve the PF.

    Then use the following web site to compute the capacitor kVAr needed to improve your power factor. At the link below:

    1-Change the calculation method to "kW, kVA, and new power factor".

    2-Enter the desired new power factor.

    3-Click the calculate button.

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  • 1 decade ago

    Enlist the help of the company you plan to buy it from. Its part of the service.

    There are a few considerations. You may consider just buying fixed capacitors for the large inductive loads (motors etc) and any motor supplier will size these (bear in mind the protection relays will need to be reset)

    If you buy one unit, then you need to consider how much the load will change. A capacitor bank with stages and a controller are best.

    At the end of the day, you need to consider what you are going to gain versus cost of correction equipment. Most small consumers like yourself have no penalty from the supply authority. Your losses will be a little higher than necessary but not much. Are you using power factor correction to increase capacity of the distribution network? This may be the only way its economical.

    One more point is to very careful not to oversize the capacitor. Running at a leading power factor can create very dangerous circulating currents.

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  • Anonymous
    1 decade ago

    I think the electric company would gladly help you out on that. I believe they would rather you have a pf of 1.

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