Flex or T&E

[Snailspark]

When installing multiple downlights, I always use T&E but I’ve seen a few cases where flex is used. Does it matter? Is there a reg or best practice on this? Just interested in peoples input

 

[Andy78]

Depends what suits the situation.
The downlights I use are made for twin and earth with solid core push fit connectors.

I've only really seen flex used on 30 year old jobs with a plethora of brown junction boxes in the ceiling.

 

[Dustydazzler]

I’m not a big fan of flex being used for fixed wiring , but have seen it used to loop down lighters together...

I personally would always use twin & earth

sometimes I do put the twin & earth cables into a junction then take a foot of flex to the light if the terminals are really small

 

[ForkEnigma]

When installing multiple downlights, I always use T&E but I’ve seen a few cases where flex is used. Does it matter? Is there a reg or best practice on this? Just interested in peoples input

Flex for fixed wiring is not good, got to think about current capacity. Unless your using 1.5mm which is not very easy to handle or install. Best to wire in T&E and then connect to Blue kick plugs, or any other plug system, Then use your .75 flex to connect your light fitting.

 

[radiohead]

I use T/E, but I really cant think of any reason why flex should not be used to loop between downlights.

 

[ForkEnigma]

I use T/E, but I really cant think of any reason why flex should not be used to loop between downlights.

Just current carrying capacity.

 

[Andy78]

Just current carrying capacity.

You'd just use flex of a size suited to the circuit no ?

 

[Snailspark]

I’m not a big fan of flex being used for fixed wiring , but have seen it used to loop down lighters together...

I personally would always use twin & earth

sometimes I do put the twin & earth cables into a junction then take a foot of flex to the light if the terminals are really small

That sounds sensible - I have seen flex used mainly in new build constructions so don’t know if it is just quicker or cheaper for the contractor than to use t&e.
looping t&e using connectors with the flex used to connect directly to the downlight would be the only thing I might do, but generally it’s t&e all the way for me. I just wondered why people used flex instead of t&e

 

[ForkEnigma]

That sounds sensible - I have seen flex used mainly in new build constructions so don’t know if it is just quicker or cheaper for the contractor than to use t&e.
looping t&e using connectors with the flex used to connect directly to the downlight would be the only thing I might do, but generally it’s t&e all the way for me. I just wondered why people used flex instead of t&e

Happens m8, probably to get job over line, then never replaced.

 

[davesparks]

Flex for fixed wiring is not good, got to think about current capacity.

Calculating cable size is no different to any other cable.

Flex is perfectly acceptable for fixed installations.

I prefer to use flexible conductors for anything 16mm and above wherever possible because its much easier to install

 

[MJPD29]

Just current carrying capacity.

Flex CCC is higher than t and e for same size

 

[davesparks]

I’m not a big fan of flex being used for fixed wiring ,

Pull a few circuits in 25mm+ singles with us and you'll soon become a fan of flexible conductors for fixed wiring.

 

[jackhammerJIM]

I use T/E, but I really cant think of any reason why flex should not be used to loop between downlights.

I can . Flex is nearly double the cost of the equivalent twin and earth .
[automerge]1594847488[/automerge]

I’m not a big fan of flex being used for fixed wiring ,

I personally would always use twin & earth

In the domestic world maybe but in commercial/industrial it is used heavily

 

[Dustydazzler]

Pull a few circuits in 25mm+ singles with us and you'll soon become a fan of flexible conductors for fixed wiring.

I should have said used for domestic fixed wiring...

I have installed some large csa flex cables in commercial installs , mainly during my apprenticeship when i helped run cables in for UPS systems...
tri rated flex iirc about 50-60mm csa

 

[davesparks]

I should have said used for domestic fixed wiring...

For domestic I have mostly only installed flex for external surface wiring (black rubber) or for boiler controls where the number of cores required dictated the cable choice.

 

[ForkEnigma]

Flex CCC is higher than t and e for same size

Depends on how its installed. Many derating factors

 

[James]

Depends on how its installed. Many derating factors

Can you provide an example of a flexible cable that has a lower current capacity than twin and earth (same csa) using the derating factors for any method of install?

 

[Dustydazzler]

Flex is generally more expensive and slightly more awkward to strip imo...I recently fitted some hi-tuff flex and it was absolutely horrible to strip.
in a domestic house I can’t see why anyone would want to use it for fixed wiring , except for multi core boiler wiring and clipping surface for exterior jobs...

 

[radiohead]

I think a lot of the dislike of flex for fixed wiring in domestics comes from it's undoubted 'DIY' feel, nothing more than that.
Ultimately as long as it's of the correct current rating and properly terminated then there is no reason why it should not be used where the installer has a preference.
All of the reasons given above amount to no more than personal preference and not valid technical reasons why flex should not be used.