Public street lights trips my RCD

Discussion in 'Electricians' Talk' started by myhouse6, May 15, 2019.

  1. myhouse6

    myhouse6 New Member

    Hello,
    I have a very strange problem in my apartment. Every day in the morning and the evening, my one and only RCD in my apartment trips exactly the same second as the public street/road lights turns on and off (evening, morning). My RCD, is Type A(C) with brand ”Sassin”, model 3SL36, 40A, 0.03A). I have had an electrician to check out but he cant find out where the problem resides or what a possible solution could be. Its 1-phase (zero and phase) incoming power to apartment. I also have 3 AC inverters (Fujitsu) Air-conditioners (2 of these serie-connected into one power source), all three AC inverters connected into 2 different fuse-groups which might affect something. After long investigation to narrow down the problem and devices, I have found out that when i disconnect the air conditioners only, and the street lights turns on/off, the RCD does NOT trip.
    So, I believe the power-peak from the street lights hitting my apartment in combo with my AC-inverters are the problem, but the big question is to solve it...

    Any help and advice here would be of great value!
     
    Last edited: May 15, 2019
  2. Comlec

    Comlec Well-Known Member

  3. myhouse6

    myhouse6 New Member

  4. Comlec

    Comlec Well-Known Member

    You have posted to a UK forum. You may get some help from others with experience of your installation.
     
  5. myhouse6

    myhouse6 New Member

    Oh, apologize.
     
  6. Bob Rathbone

    Bob Rathbone Well-Known Member

    OK, so here is the problem that you have. The air con inverters have an electronic filter at the input. It consists of a couple of chokes and 3 capacitors, on between phase and neutral and the other two from phase to earth and neutral to earth. the purpose of these devices is to short to earth any high frequency pulses that your inverter may export to the house wiring. When the street lights turn on, if they are HPSV types, salmon pink colour, their is an igniter in the circuit to start the lamp. This igniter produces a string of high frequency pulses, these pulses are appearing on the public supply system and are being shorted to earth by the input filter in the inverter. Your RCD sees this current to earth as an earth fault and responds accordingly, by tripping. You have confirmed to me that when the air con is disconnected the problem goes away, so I am positive that my assessment is the correct one. Now, how to fix it, Spain is in the EU, who have strict rules on conducted and radiated electro magnetic pulses from equipment, including street light control gear. Your local council will be in charge of the lighting, talk to them first as your nearest street light may be faulty causing the igniter to work harder. If you get no response talk to the electricity supply people, their supply network is being contaminated by their interference from the street lighting and they have the power to do something about it, ie order it to be fixed. Good luck.
     
    longboat, rogerk101 and robertpstubbs like this.
  7. myhouse6

    myhouse6 New Member

    Bob Rathbone. Big big thanks to you and your answer. So much appreciated! I will follow your advice. :)
     
  8. myhouse6

    myhouse6 New Member

    Bob Rathbone: 3 follow up questions:
    1) Do you know which type of RCD that is best for AC inverters?
    2) Can a correct type of RCD prevent it from tripping with regards to the high frequent pulses from the street lights?
    3) Any idea of a temporary solution until the local council (might take very long time) isolates the interference from the street lights.

    Again, big thanks for very well explanation to the problem I have.
     
  9. peter palmer

    peter palmer Well-Known Member

    Can some filtering not be put onto the incomer before the RCD to take away the harmonics, I'm thinking some kind of snubber network across the electric meter or incoming tails?
     
  10. myhouse6

    myhouse6 New Member

    Peter palmer. Thats also what I was thinking about to install before the RCD and after the incoming power. I’ve tried to google on ”RC filter”, ”AC-filter”, snubber interference” etc but cant really find something that clearly says it will harmonize incoming interference/eliminate high frequences inputs in an apartment/house.
     
    Last edited: May 16, 2019

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