This is a question we are commonly asked at Elkay Technical and it particularly relates to 2 wire (Live and switch Live) products without a neutral. It does not relate to large loads or to prodiucts with a neutral (3 wire).
Difference between an ordinary light switch and an electronic switch
It is important to understand is the difference between an ordinary light switch and an electronic switch. An ordinary light switch will open and close the circuit when in operation and this means that in the open condition no energy is in the circuit.
However an electronic switch without a neutral has to utilise the switch live in the off condition, to run its various functions, which allows some energy to continue in the circuit. It is this small amount of energy that can sometimes be picked up by the load and cause a lighting load to flicker.
The problem of lamps staying on is sometimes exascerbated when using combined emergency lighting, for example, because this type of luminaire needs sometimes less than 30 volts. With the advent of LED technology, which can run with 1 to 16 watts of power, attention to this problem is essential.
How to fit it?
- By fitting a capacitor any quiescent current is taken away and not used until the switch is activated again. Capacitors should be fitted at the light fitting across the switch live and neutral. The capacitor should be 250V 4uF (4microFarads) or above for the majority of loads.
- Capacitors are fast becoming an essential piece of kit for electricians who now almost exclusively fit low power loads in this energy conscious age.
- Capacitors (Product code PFCC-1) are available from your local stockist.
- For more information call Elkay Technical on (02890) 616505.
