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High 3rd harmonic on the neutral

MS01
Afternoon,

I was wondering if anyone has nay experiences of having issues with high 3rd harmonic currents on the neutral on high-rised residential schemes? I appreciate  non-linear single phase loads will impact the 3rd harmonic and even on a balanced system harmonics are an issue but we are measuring it at 300% but I can’t think why this may be the case on a residential building.

Does anyone have any ideas?



M
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  • 0
    I particularly like Andy Jewsbury`s DC explantion.

    I do something similar myself when explaing apparent power and real power (even some electricians struggle to grasp it)

    I usualy say something like imagine A DC supply and remember Pythagoras and his right angled triangle. If you send 5V from a supply (battery or whatever) to whatever is using power then in in turn it sends 1V back because it does not need it, then it has only used 4V needs to create 5V just to send it. Of course you could imagine the same in Amps or Watts.


    Off course I then tell them that it is actually all a lie because power factors only work with AC not DC but I think it helps in simple terms to explain that you are generating large amounts to receive far smaller amounts and use them..

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  • 0
    I particularly like Andy Jewsbury`s DC explantion.

    I do something similar myself when explaing apparent power and real power (even some electricians struggle to grasp it)

    I usualy say something like imagine A DC supply and remember Pythagoras and his right angled triangle. If you send 5V from a supply (battery or whatever) to whatever is using power then in in turn it sends 1V back because it does not need it, then it has only used 4V needs to create 5V just to send it. Of course you could imagine the same in Amps or Watts.


    Off course I then tell them that it is actually all a lie because power factors only work with AC not DC but I think it helps in simple terms to explain that you are generating large amounts to receive far smaller amounts and use them..

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