Calculate for full load conditions

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  • Gtfast
    Full Member

    • Apr 2016
    • 78

    #1

    Calculate for full load conditions

    Good day

    As per the below reg what calculation is the calculation for full load conditions.

    I know we used 50 percent of circuit load in older regs.I am not sure what this is refering too.


    8.6.10 Voltage, at distribution board — on load
    Switch on the maximum available load and measure the voltage at the point of
    control. Calculate for full load conditions and notify the supplier (see annex H)
    if that voltage will be outside the regulatory limits (see 5.4.2).

    Thank you

    Sent from my CPH2197 using Tapatalk
  • Derlyn
    Platinum Member

    • Mar 2019
    • 1748

    #2
    Originally posted by Gtfast
    Good day

    As per the below reg what calculation is the calculation for full load conditions.

    I know we used 50 percent of circuit load in older regs.I am not sure what this is refering too.


    8.6.10 Voltage, at distribution board — on load
    Switch on the maximum available load and measure the voltage at the point of
    control. Calculate for full load conditions and notify the supplier (see annex H)
    if that voltage will be outside the regulatory limits (see 5.4.2).

    Thank you

    Sent from my CPH2197 using Tapatalk
    You need not use 50% of full load. Any percentage will work as the volt drop will be directly proportional to the load drawn.

    Remember this test is not carried out to test any wiring on the installation.
    It is done to test the volt drop on the incoming supply cable.

    Example.

    A domestic 60A supply is a 15kW supply.
    Check what size element is in the geyser. For this exersize lets use 3Kw. ( 1/5th of full load )
    Turn off all loads.
    1. Measure voltage at point of control. ( main breaker )
    2. Turn on geyser (3kW)
    3. Measure voltage at point of control again.
    4. Note the difference.
    5. Multiply the difference by 5. That will be the volt drop at 15kW.
    6. Subtract the answer obtained in 5 above from the reading obtained with no load at point 1 above.

    The result must be within the parameters set out in 5.4.2

    If you use, for instance a load of 5kW for the test, then in point 5 above, you will multiply by 3 to get full load and so on.

    Hope this helps.

    Comment

    • Gtfast
      Full Member

      • Apr 2016
      • 78

      #3
      Thanks Derlyn
      I can know rest.

      Sent from my CPH2197 using Tapatalk

      Comment

      • Gtfast
        Full Member

        • Apr 2016
        • 78

        #4
        Good day

        If one has a 3 phase and neutral system .How would one do the voltage at distribution board- on load calculation as per .

        8.6.10 Voltage, at distribution board — on load

        Switch on the maximum available load and measure the voltage at the point of

        control. Calculate for full load conditions and notify the supplier (see annex H)

        if that voltage will be outside the regulatory limits (see 5.4.2).

        Do the calculation as per annexure D?
        Use the same method as for single phase for live to neutral?

        Anyone know where I can get literature on this.



        Sent from my CPH2197 using Tapatalk

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