lightning and earth leakages

[Greg]

I notice this is becoming more common.

Where when one has thunderstorms earth leakages trip. One then resets them, they go on first time but as soon as the lightning or thunder starts they trip again.

I have normally found that replacing the units helps due to the fact that over years the earth leakages become sesitive to lightning and thunder. But lately that does not even help.

One particular job in question:

They have over head LV lines in the area that bring the power in to the plots.

The earth leakages trip as stated above. I even went as far as to install two 3 phase earth leakages in the db that were connected on the supply side but had no conductors on the load side. This past weekend we had heavy thunder storms in JHB on Saturday and Sunday nights. Both those earth leakages were tripping.

I want to check the Loop impedance to see if that is to high. If that is high I would assume this could be adding to my problem because I have a bad earth.

Any other suggestions or thoughts?

As I say this is becoming very common.

[AndyD]

High earth impedence will cause slower tripping times. There are auto-restart earth leakages but I doubt they'd be less prone to tripping, it would just save them needing to be reset every time there'sa storm.

Did you do an IR test on the installation, if there's a high standing leakage current that's close to the tripping threshold this might make it more prone to tripping during storms.

[murdock]

i was called out to an earth leakage tripping...when i arrived everthing looking fine but the e/l unit would not stay up...i noticed a small hole the size of a pin head in the front of the unit...it was empty...when i opened the unit it had no metal components...they must have melted from a lightning strike and sprayed out the hole in the front of the unit...i can only asume this as i there was like a dust layer on the counter and floor in front of the unit...and i didnt see what happened.

[Yogs]

Hi greg. Trust all is well. I have been having the same problem at my place. It is getting so frustrating. Have you managed to find a solution ? I am not a electrician so its very hard to even figure out what's the cause. I have replaced the earth leakage with a new one with a overload and thought that would maybe assist(a private electrian said this will maybe work as the previous E/L was doing the same), but this has not at all worked. Any body have any ideas ?

[nicobotha1]

i have the same problem with a e/l with thunder storm i find that the cbi products have a problem i replace two of them and find the sensetivity on the products was very high i put the third one in problem solved

[AndyD]

You could try installing surge arrestors if there aren't any already there. They should be installed in lightning prone areas anyway.

[Yogs]

Thanks AndyD for the suggestion. I have no idea what a surge arrestor looks like so I i'm not sure if its there already.
Its just very odd that the E/L are so sensitive. Even if the lightning if far away the E/L trips. As well in this case if its like heavy thunder its doing the same thing. To be honest I think I really need a Honest, reliable, professional Electrician who knows what his doing to sort this board of mine out. Unfortunately a electrician with these qualities are hard to come by these days.

[AndyD]

I think I really need a Honest, reliable, professional Electrician who knows what his doing to sort this board of mine out.

That was going to be my next suggestion. I would test the DB and earthing arrangement before you go any further.