still current while rcd trip off?

[ekon]

Wanted to change a lighting fitting yesterday..I have 3 x 6 amp rcd -protected circuits so I located the correct one and flicked the trip-switch off manually.

I did a job last year on another light fitting and got a bit of a tickle with the rcd switched to off!..so I switched all power off at the box that time...but I'll be honest I did not get anyone to look at things then..maybe I should have.

Yesterday I put a meter on the one I wanted to work on and with the bulb having been extinguished as the rcd had been switched to off ...there was nevertheless about 120volts there when I hooked the meter up (can't be more accurate as it is an old-style swinging pointer meter ...not digital).

Before I get an electrician out can anyone suggest a possible cause(s)..as power seem to be leaking past the rcd switch on this circuit?

p.s. just checked the meter on a "switched off " socket i.e. with the relevant rcd switched to "off" position....no voltage on that.

 

[Softus]

First question: why have you got ANY lighting on an RCD protected circuit?!

 

[securespark]

Cyprus. Use of RCD incomers & RCBO's prevalent there. Maybe it's TT too.

C types common, too.

 

[Softus]

Well, I didn't assume that the rules are the same, but surely common sense doesn't recognise national borders?

 

[securespark]

Next time you go to the continent, have a look at some consumer units!

Plus, if it's TT, we have RCD's on lighting too...

 

[plugwash]

to the original poster the first thing we need to establish is whether when you say RCDs you mean MCBs.

if you mean MCBs then in many cases they only isolate the live, this means that if there is a potential between neutral and earth you may get a small shock. Have you used your multimeter to check for this possibility?

also are you really in cypress?

as always photos would be nice.

 

[Softus]

Next time you go to the continent, have a look at some consumer units!

I did that once and got really scared.

Plus, if it's TT, we have RCD's on lighting too...

Well, I know, on the isolator, but on the ways?

 

[ekon]

my sincere apologies for any confusion I have caused..plugwash is right I did mean mcb...sorry had also fitted an rcd double-socket for external use recently..."rcd" was still embeded in my brain! Yes so the mcb for this lighting circuitwas switched to "off" manually and the meter showed 120volts still there when probes inserted into L&N terminals.

....yes I am in Cyprus...weather is just beginning to warm up properly...its been a bit cool for May this year.. 20-22C of late..this a.m clear skies and 24C at 10.18 local time....soon be up in the 30s at this time of day

 

[plugwash]

have you measured the voltage at the intake all three ways (live-earth, live-neutral and earth-neutral)?

 

[ekon]

no I just measured between the live and neutral at the litle terminals behind where the bulb (normlly) screws in to the holder. I didnt expect to find a voltage present there