Job Tonight

[lineman]

Evening Gents,

Don't often ask for help on a job just need some advice to prove that I'm not going mad. Got called to a house tonight where the client complained of receiving shocks from a light switch (plastic). After an attempted demonstration which resulted in me nearly rugby tackling the old lady to prevent her getting zapped I set to work. Metal pattress, cpc terminated in lug, ELI on lighting circuit ok, R1+R2 ok, long lead method between florry kitchen light and switch, piggy-backed eli test , continuity between faceplate screw and cooker door hinge, water pipes, gas pipes, MET, ring final cpc, sink etc etc tried everything. Earthing was up to scratch 100%. Now she shuffles across the carpet in a pair of crocs to turn the light on. Must be a static shock, any thoughts?

 

[m4tty]

Defo sounds like static

 

[Manator]

Almost certainly static, the metal back box will be earthed and she is sometimes touching the plate screws when operating the light.

 

[rich.250]

Switch arching?? Wet hands??

Deteriorated switch?

Something could have damaged insulation and plastic. Oil or something?

Have you tried it? Lol

 

[alpha spark]

I've had static shocks before but mine was on a suspended ceiling every time I touched it beleive me it hurts I did all the checks as u must of spent 3 hours thinking the ceiling grid was live and it was static in the end I bought some marigolds lol

 

[rich.250]

If it is static, fit a switch with screw covers. Problem solved lol. Saves her panicking

 

[lineman]

Yeah tried it! No shock. Kinda knew it was static just the thought of one of customers getting shocks makes me go cold just wanted to reassure my conscience! ended up fitting two white plastic bungs from a manrose ex fan just to blank off the screws and changed the switch.

 

[Manator]

Actually thinking about it any static charge can be instantly discharged if touching anything with a lower charge, just like if you touch another person after shuffling along a nylon carpet.

 

[rich.250]

Probably what she was doing. Shuffling along the carpet and charging... Lol.

Then discharging to earth lol

 

[Evans Electric]

Did this happen when the immersion heater was working ?

I always say this because I've been fooled in the past . If immersion is leaking to earth through the elements in the water and protection is rewirable with no RCD, the fuse won't blow but the potential rises on the earthing , pipework and often the sink top.

The static would be discharging onto anything thats earthed.

Its easy to be fooled , I'd always do an IR test on the Imm. Htr ....specially when they say it happens at certain times, as in time switch control or stat switching on and off.

 

[OnOff]

Nylon screws + new switch + new slippers!

 

[kme]

I`d ALWAYS replace the switch in this scenario - just on the happenchance that a tiny hairline crack has made its presence known........