RCD and PIR LED lights

15 Jan 2022
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United Kingdom
I recently installed a Homezone LED PIR light on my garage which I plug in to the garage socket.

All worked well when switched on the lights lit up and after some minutes went out, I checked the PIR and it turned the lights on. However after ten minutes the House RCD tripped. I already have the same light fixture over the front door so I thought the new fitting must be faulty, I went back to Cost..and swapped for a new one. Went home fitted it and the same result. I read somwher that these units have some earth leakage and I guess the addition of a second unit (same as the front door one has taken the RCD to its limit, but why the delay? is that built into the RCD?

On reflection I decided to fit an older spare chines one I had kicking around in the garage, the tail was very short so I opened up the unit to find that the earth wire inside was floating around in the breeze with no visible connection point on the metal casing. surely that cannot be legal? In any case it wouldnt trip the RCD I guess.

Is there a solution that will allow me to use the new unit?

Sorry its a long post but I have searched Tinterweb with no joy.

Thanks in advance.
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Modern RCD measures imbalance line - neutral and it assumes most likely cause is leakage of one to earth. In the main we use a 30 mA RCD which must not trip at 15 mA and must trip at 30 mA and at 150 mA must trip within 40 mS. In the main they do trip at around 25 mA. We have three tools.
1) RCD tester.
2) Insulation resistance tester (uses 250 or 500 volt).
3) Low current clamp-on ammeter.
It is permitted to have below 3.5 mA leakage on a device, although rare to get anywhere near limit, and for a collection of devices with no fault 9 mA. With a RCD tester using 15 mA as long as circuits active when tested any drain over 9 mA is likely to cause a trip, so I never actually measured that 9 mA, mainly as did not have a clamp-on that would go that low.

However the DIY guy rarely has the meters, so it is simply trust to the lord. Well not quite that bad, in the main we have two or more RCD's odd one out is narrow boats and caravans, so we can test devices on a circuit powered by the other RCD, I got an insulation tester for £35 new, but the rest of the test equipment tends to get expensive.

Main problem is water, and I drilled a small hole in bottom of my outside light to let the water out, being careful not to hit any components, with quartz they got hot driving water out, LED do not get that hot.

So as a DIY person only option seems to be an extension lead and power from different RCD to test it.
surely that cannot be legal?
It isn't. Dangerous illegal junk.

In any case it wouldnt trip the RCD I guess.
Not with a fault in the device. If the casing became live and someone touched it, the RCD might trip. Or it might just kill someone.

I read somwher that these units have some earth leakage
They may, but two of them won't be anywhere near the amount to trip an RCD.
RCD's of the type normally used in domestic consumer units don't have any delay.
The trip is very likely due to a fault somewhere, moisture ingress, damaged cable or similar.
Or there was already a certain amount of leakage due to some other problems, and the addition of the light increased that to a level which will trip the RCD.

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