0.75mm Flex - Bathroom Light

[Weeball]

Hi all,

I’m sure this should be an easy question for someone. Basically, am I OK to use 0.75mm flex in the below installation?

At present, there’s a batten style bulb holder and ceiling rose in my bathroom. I’m going to replace this with a 25w LED bathroom light. The bathroom light I’m fitting has a plastic enclosure, so only has live and neutral terminals.

I’ve replaced a few ceiling roses around the house with modern light fittings using wago connectors and boxes. They’ve all been metal enclosure fittings (live, neutral & earth terminals), so I’ve used a small length of 3 core flex from the wagobox to the light fitting. I’ve always used 1.5mm flex for this as was told for light circuits you normally use 1.5mm cable.

So for this job I intend to use wago connectors and a wagobox, but only need 2 core flex from the wagobox to the light fitting. Thing is, my local Screwfix is all out of 2 core 1.5mm flex. They have 2 core 0.75mm flex in stock though and I’m pretty sure this should be safe to use considering it’s only a 25W light, but I wanted to make sure first? The light circuit ring is protected by a 6amp MCB in the consumer box.

Thanks in advance to anyone who responds.

 

[winston1]

I’ve always used 1.5mm flex for this as was told for light circuits you normally use 1.5mm cable.

You were told wrong. Light circuits only require 1mm cable. 0.75mm is too small with a 6a MCB. You should use 3 core flex of the correct size and put the earth wire in a terminal block in case someone else in the future changes the light for a metal fitting. *See replies below for a correction

 

[Weeball]

Thanks for the response Winston. So, the minimum size of flex I should use is 1mm? I have a length of 3 core 1.5mm flex already so would this be ok to use?

 

[sircerebus666]

You were told wrong. Light circuits only require 1mm cable. 0.75mm is too small with a 6a MCB. You should use 3 core flex of the correct size and put the earth wire in a terminal block in case someone else in the future changes the light for a metal fitting.

Huh?

Last time I checked 0.75mm is rated at 6A and I'm pretty sure most 6" or 9" pendants are wired in 0.75mm flex

 

[winston1]

Thanks for the response Winston. So, the minimum size of flex I should use is 1mm? I have a length of 3 core 1.5mm flex already so would this be ok to use?

Yes

 

[winston1]

Huh?

Last time I checked 0.75mm is rated at 6A and I'm pretty sure most 6" or 9" pendants are wired in 0.75mm flex

OK I seemed to think 0.75 was rated at 3a. Thanks for the correction.

 

[Weeball]

Brilliant, thanks for the responses. I really appreciate your time.

 

[Weeball]

Ok, for future knowledge, 0.75mm 3 core flex (with the earth in a terminal block) would be safe to use in this instance?

 

[JohnD]

was told for light circuits you normally use 1.5mm cable.

You were told correct.

Normal people do use 1.5mm fixed cable on lighting circuits.

For the flex connecting a ceiling rose to a bulbholder, 0.75mm is suitable in domestic installations. (commercial and industrial installations may be rated higher).

 

[sircerebus666]

Ok, for future knowledge, 0.75mm 3 core flex (with the earth in a terminal block) would be safe to use in this instance?

Yes

 

[Weeball]

Thanks again Winston1

 

[Weeball]

And thanks John D too

 

[EFLImpudence]

What is going on?

"Normal people" meaning most people do not use 1.5mm² cable for lights.

0.75mm² flex IS rated at 6A.



Anyway -

25W seems a lot for an LED light. Are you sure?
Even if it is 25W, that is one tenth of an amp, so virtually any size of flex could be used.

 

[Weeball]

Hi ELF, thanks for the response.

I was always under the impression you use 1.5mm for lighting circuits.

Here is the link to the bathroom light
https://www.amazon.co.uk/Waterproof...uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

[Weeball]

Sorry, it’s actually 15w!!!!