Tripping lights

[PrenticeBoyofDerry]

Explain the wires,
White heat resistant sleeved=?
Three black cores=?
Your contribution to wiring?
I assume the lower connection block is to interlink?
Do you have the MI for the units?

 

[Wilf1982]

The only wires I have connected are the brown grey and black at the bottom which are from the swa. The block was labeled L N and earth everything else was factory fitted.

 

[bernardgreen]

The centre terminal is the earth terminal to which you have connected the grey wire. Does the other end of the SWA have that grey wire connected to anything ? Obviously it should be connected to earth but is it ?.

If it was connected INCORRECTLY to a neutral other than the neutral bar of the RCD then that could explain the tripping when the lamps were turned off. It would also make the fittings unsafe as they would not be correctly earthed.

That is a choke, not a transformer. Chokes restrict the flow of AC current to the control the current through the lamp. When the lamp is turned off any stored energy in the choke ( magnetic flux ) will create a high voltage spike which has enough energy to trip an RCD if the unit is not correctly connected. If the energy dissipates equally via live and neutral through the RCD sensor then a trip should not occur. However this cannot happen as the live is open circuit at the switch.

The high voltage means capactive couplings ( transformer to lamp chassis etc ) have more effect during the spike than they have at 230 volt so if capacitive coupling to the chassis provides a parallel route to neutral then the dissipation of the stored energy via the RCD sensor is unbalanced and a trip can occur.

If the unit had a power factor capacitor fitted that would absorb the energy.

You could try a snubber across live and neutral in the lamps to absorb some of the spike.

A capacitor 0.1uF micro Farads 250 volts AC in series with a resistor 47 ohm connected between switched live and neutral should aborb the spike.

Which come pre-packaged as a contact suppressor from RS Components

PMR209 0.1uF 47R250Vac

RS Stock No. 209-229
Manufacturer Evox-Rifa
Manufacturers Part No. PMR209MC6100M047

 

[securespark]

There also appears to be a lot of moisture on that fitting. That could be a factor.

 

[Wilf1982]

Sorted. I installed the contact suppressor as advised by bernardgreen which has solved the problem. The lights work fine now with no tripping. Thanks everyone for the help especially bernardgreen.