Anyone know why this capacitor was installed?

Quba101 · Aug 22, 2024

I'm currently working in a building that was completed in 2006. All the lighting is switched by wall mounted PIR and these capacitors seem to be installed at every PIR connection behind a blank plate. The capacitor is connected between the switched line and N Just wondering if these were needed for the old lights as every light is LED now?

[ElectriciansForums.net] Anyone know why this capacitor was installed?

mainline · Aug 22, 2024

Quba101 said:
I'm currently working in a building that was completed in 2006. All the lighting is switched by wall mounted PIR and these capacitors seem to be installed at every PIR connection behind a blank plate. The capacitor is connected between the switched line and N Just wondering if these were needed for the old lights as every light is LED now? View attachment 117801

There was probably a relay, inductive load involved, so used a capacitor for induction suppression.

loz2754 · Aug 22, 2024

Looks to me like it's being used as a snubber to prevent the LEDs from glowing even when the switch is off, due to the effect of capacitance in the cables.

freddo · Aug 22, 2024

Caps were also required when the lights were a small load to operate correctly with some 2 wire PIRs and timer switches that have no neutral connection. The timers current draw would be enough to make some fluorescent lights flicker etc.

mainline · Aug 23, 2024

loz2754 said:
Looks to me like it's being used as a snubber to prevent the LEDs from glowing even when the switch is off, due to the effect of capacitance in the cables.

The op said it’s leds now so I assume it wasn’t before