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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> 110 volt lighting circuit https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1380311317 Message started by PTY on Sep 27^th, 2013, 8:48pm

Title: 110 volt lighting circuit
Post by PTY on Sep 27^th, 2013, 8:48pm

Hi Everyone, If i wire a conventional lighting circuit using a 110v (55v-55v) power supply via a double pole mcb in a consumer unit. If i use a single pole switch to control the light will it be classed as a safe condition when the switch is in the off position as there will still be 55v at the light. Is there any regulation that covers this situation?
Come on Spark's can you help!

Title: Re: 110 volt lighting circuit
Post by big_all on Sep 27^th, 2013, 9:27pm

heeelllooo and welcome PTY ;D ;D ;D

lectrician or others will be along soon
is this in the uk
and go on tell us whats it for ::) ::)

Title: Re: 110 volt lighting circuit
Post by Lectrician on Sep 27^th, 2013, 9:29pm

You would need double pole light switches in addition to your double pole MCB in my opinion :)

Title: Re: 110 volt lighting circuit
Post by PTY on Sep 27^th, 2013, 9:30pm

Hi Big Al,
Yep it's in an installation in Scotland

Title: Re: 110 volt lighting circuit
Post by PTY on Sep 27^th, 2013, 9:51pm

It was originally a 230v klik emergency lighting installation and at the last minute the client said he only has 110v (55v-55v)in this area. I changed the single pole switch for a double pole type but then realised the Klik box has a shared neutal and when you switched the lights off the emergency light would energise. So i said we would have to use a ordinary j/b system and remove the Klik box. My engineer said it will still work if you put back the single pole swicht, i am not happy as there would be 55v still present at the light fittings and i am not sure if this meets with the current regs? I am waiting to hear my engineers responce on Monday. What do you think.

Title: Re: 110 volt lighting circuit
Post by Lectrician on Sep 27^th, 2013, 10:16pm

It's dirty, but a switch is only "functional switching", so if there is DP isolation elsewhere, I guess it does comply...

Title: Re: 110 volt lighting circuit
Post by PTY on Sep 28^th, 2013, 9:33am

Hi Lectrician, thanks for your comments and i agree with you, but i am old school and like to think that when i switch something off--it's off, so i will put my case forward and insist on double pole switches.