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Thread: Negative Power Factor

  1. #1
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    Negative Power Factor

    Hello

    Can anyone please assist me,
    Am instructed to install a power factor correction banks for a certain DB, The reading from that panel are;

    kW -31.3
    kVA 49.2
    kVAR 38.1
    PF -0.63
    Amps L1 70A
    L2 73A
    L3 72A
    My question is: Why is the power factor negative, even the real power is negative

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  2. #2
    Diamond Member Justloadit's Avatar
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    Sounds like an incorrect connection to your instruments, usually the current transformer is either inverted, in other words invert and reconnect, or alternatively you have the CTs on the incorrect phases with respect to the voltage measurement probes.
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    Fluke 434 or 435, assuming it is a 435 because I don't think the 434 has energy capabilities.

    How long have you been using it?

    Do you understand how to set it up, and do you use the vector diagram to set it up to make sure the leads and clamps are connected correctly?

    Have you configured the meter correctly.

    Do you understand the difference between an inductive load and a capacitive load?

    The meter is indicating that it is a capacitive load.

    The reason I ask all these questions, is to understand how much you know about this meter. It took me 3 years to understand my 435, and most of the mistakes I made in the beginning were due to incorrect connections or parameter settings, no thanks to fluke SA.

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    Diamond Member AndyD's Avatar
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    Your load is certainly well ballanced. What type of load is it?
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    Its a Fluke 435, this will be my third time using it. My first and second time worked very well.
    The meter comes with the leads clearly marked voltage inputs(E,N,R,W,B) and current inputs(N,R,W,B with arrow for current flows)

    Once I have connected all the leads, I switch on the meter > go to menu > then Logger > I then clear out the logging from the memory and rename > Adjust the duration of logging I always set it for 1 week and then I start.

    Is that right?

  6. #6
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    Quote Originally Posted by Justloadit View Post
    Sounds like an incorrect connection to your instruments, usually the current transformer is either inverted, in other words invert and reconnect, or alternatively you have the CTs on the incorrect phases with respect to the voltage measurement probes.
    In will go check again today. You might be right

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    You need to setup the parameters in the meter to what you want to achieve, then connect your leads, making sure they are correct by using the vector diagram which if setup correctly the outside arrow will be facing the correct direction, the current and voltage arrows in the correct position, then you are ready to start logging.

    A capacitive load indicated on the screen would mean you have way to much power factor correction or there is something wrong with the setup of the meter or connections.

    When I started using the fluke 435 for fault finding in 2006, I thought it would be like using my 86 or 189 or 289, connect and look at the screen, the 435 is a complex piece of equipment and requires hours of training to set it up to use it correctly to achieve optimum results. It took me about 2 years to understand the meter then another 3 years to understand the results once downloaded (learnt by downloading and reading info and watching online seminars). At the time I purchased my unit not even the people who sold me the meter knew how to set it up. I do believe comtest have managed to educate their staff and make them a little more competent with using the 435.

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