Is it normal to have a red light when the light switch is turned on?

[iron1899]

 

[plugwash]

Is that switch plate metal, or is it plastic pretending to be metal, I can't tell.

If it's metal, then the switch plate should be earthed, which should stop the non-contact detector picking anything up.

If it's plastic, then it's not something to worry about. By their nature, non-contact detectors can pick up live conductors without direct metal to metal contact.

 

[iron1899]

Thanks that's a relief. Yes it's plastic.

I've touched the switch plate and screws with my fingers and no shocks

 

[EFLImpudence]

Just to say the detector would still light near the Line conductor if the switch was off.

It detects Voltage; not current.

 

[iron1899]

Just to say the detector would still light near the Line conductor if the switch was off.

It detects Voltage; not current.

NCVT shows green and not red when light switch is turned off. Does that mean I might have an issue?

 

[EFLImpudence]

NCVT shows green and not red when light switch is turned off. Does that mean I might have an issue?

All over the switch?

 

[ericmark]

What do the instructions say for the NCV detector, I have three, each slightly different, the use of dashes is common, one to 3 or 4, and also a pulsing buzzer which varies with pulse speed, and a chart to show different voltages which are claimed to activate each bar. In real terms, not really voltage, but how close the tester is to the voltage being detected.

 

[robinbanks]

Took one of those back to Screwfix once, because it beeped every time I touched my head with it, and there was definitely no electrical activity anywhere near

They're nearly useless as a proper diagnostic tool; use a multimeter instead

 

[ericmark]

They're nearly useless as a proper diagnostic tool; use a multimeter instead

In my case, it is part of my multi-meter. What we often want is to test if there is likely power at a switch or socket before we remove any screws, contact voltage testers can't do that, be it a neon screwdriver or Avo Mk8 they all have their uses.

Shown is my NCV detector showing all four - so maximum voltage which it will detect as no contact volts. I would consider this as multi-meter, but in this mode doing the same as the pen tester shown by @iron1899 I have in all four testers with this function, the instructions for one as said, gives each - a voltage.