Armoured cable

[ey143]

Hi

Just to satisfy my own curiosity, at what point is an armoured cable needed? Is it purely when running mains cable significantly outside or can an ordinary 3 core and earth cable run from an internal fuse board / consumer unit and through the external wall to an isolator switch or into an external lamp secured to a wall?

 

[AndyPRK]

As long as the T&E goes rear entry into the light, it is fine.

you don’t want it exposed to sunlight

 

[333rocky333]

The main reason armoured is used, is when Mechanical protection is needed, I dont recall any other reason why it would need using, in certain cases it can be a disadvantage to use regarding terminating it at an accessory

 

[plugwash]

AIUI it's ok to run regular T&E or 3&E into the back of a light, but it shouldn't really be exposed outdoors due to lack of UV resistance.

Armored cable is used for protection when burried or otherwise subject to damage but as 333rocky333 says it can be difficult to terminate into things not designed for it. For this reason you will often see armored cable terminated in a box near a load and then some other cable type used for the final connection.

Unfortunately the traditional UK cable types don't seem to include an "outdoor non-armored fixed wiring cable". Use of black rubber flex is common for lower-powered stuff like outside lighting and pond pumps. Use of the german cable type NYY-J seems to be becoming popular for higher-current outdoor work.

 

[333rocky333]

Seem to see Black Fp200 type cable used wall mounted outside, though the White does not stand up too good to the Uv and seems to crack up

 

[JohnW2]

The main reason armoured is used, is when Mechanical protection is needed, I dont recall any other reason why it would need using ...

I suppose that it's literally true that 'armour' os only needed when there is a requirement for mechanical protection. However, armoured cable is one example of a cable with an 'earthed metallic covering', which is all that is theoretically required (without 'mechanical protection') in certain situations (e.g. cables in walls outside of 'safe zones') - but armoured cable may be the easiest/most appropriate type of cable with an 'earthed metallic covering' to use.

Kind Regards, John