Random downlight flickering

[Tom edison]

Hi
Ive never seen this issue in 35years in the trade and wondered if anybody has any idears.
The property is a new build and the installation fitted by myself. We have 26 Aurora cx7 downlights on 3 seperate circuits and controlled by various switching configurations. All dimmer switches are Varilight V- pro modules and the consumer unit is the new Click Elusian split load board with SPD.
The lights flickers very randomly sometimes not for a day or 2. I have checked everthing. No loose connections. Aurora have sent new fittings which i have fitted. I've changed the dimmer modules but the problem is still there. Has anyone got any idear what this could be or has any body seen this before? I've now hit a wall as to where to look next.
Thanks

 

[Aube Electricians]

Hi
Ive never seen this issue in 35years in the trade and wondered if anybody has any idears.
The property is a new build and the installation fitted by myself. We have 26 Aurora cx7 downlights on 3 seperate circuits and controlled by various switching configurations. All dimmer switches are Varilight V- pro modules and the consumer unit is the new Click Elusian split load board with SPD.
The lights flickers very randomly sometimes not for a day or 2. I have checked everthing. No loose connections. Aurora have sent new fittings which i have fitted. I've changed the dimmer modules but the problem is still there. Has anyone got any idear what this could be or has any body seen this before? I've now hit a wall as to where to look next.
Thanks

Hi
I had a client call me recently because of flickering lights. It turned out to be a fault in the supply from the street. So not their issue at all. UK Power sorted out a loose connection and the flickering went away. So flickering can be an indication of an issue on a different circuit or the supply. The other issue I have found with V-pro dimmers is that they can affect each other. So turning one on can it seems send a pulse to another dimmer and turn that on as well. I changed dimmers to a simple model and the problem went away.

 

[Tom edison]

So update on lights. I've changed evey affected circuit to rcbos. Still doing it. I've fitted rc snubbers as suggested and still doing it. I really have nowhere else to go.??

 

[marconi]

Do you have or can you borrow a generator and use it to supply just the lighting to see if the cause is outside your home? It now strongly suggests something outside your home. Helpful things to try to find out are if anyone in your street is using occasionally high current equipment causing a voltage drop and/or equipment with high and long duration switch on current surge. Examples would be storage heaters, arc welders, car lifts, large refrigeration compressors, 10.5kW showers, heat pumps, EV chargers*.....

* Some EV chargers have power factor correction but I think I am right not all do. The nature of converting AC to DC means the power factor is reduced thus for a given real power output the current the charger draws is higher eg 0.8 PF and 7.5kW charger the current will be 0.8 = 7.5/Apparent kVA, App kVA = 7.5/0.8 so I = 7500/(0.8 x 240) = 39A cf 7500/240 = 31A. The current waveform is also 'peaky' so 39A mean current is lower than the peak current. This could be a problem ie increased inverse peaky voltage drop if several are being used on the phase which also supplies your home - see:

https://www.researchgate.net/figure/EV-charger-AC-voltage-and-current-waveform_fig1_271288791

Quite a few reports come up by googling 'LED lamps flicker when EV charger is charging'. Tesla chargers get several mentions.

https://www.diychatroom.com/threads/led-light-bulbs-slightly-flicker-when-ev-is-charging.748958/

Lights in house flicker while charging new Model 3 - https://teslamotorsclub.com/tmc/threads/lights-in-house-flicker-while-charging-new-model-3.149841/