flex wiring rules

[markthespark77]

Hi guys
whats the regulations in wiring in flex... I have a plug top ( Sure this is not allowed ) feeding a 3 m 1.0 flex, that goes under the floor boards, pops up in a cupboard then comes surface on the facing to a really old timeclock, before disappearing to an old water tank and back boiler . I have to learn more regulations, I was mostly doing new installs to the best standards, but now working for a letting agent and budgets are always tight , just want to be sure before I tell him ...I am under the impression flex is for 1 m or so..?

Thanks in advance

 

[derek preece]

You need to do cable calculations for the load, plus work out the fault currents that may arise before the protective device opperates imho

 

[markthespark77]

The flex is 1mm protcted by a 3 amp fuse, I can change the plug top to a switched fused spur...the actual cable itsself...can flex be used to hardwire?

 

[Richard Burns]

So long as the flex suitable for the load, installation method and protective device then it can be used for fixed wiring.
Normally not worth it because it costs far more than other cables

 

[derek preece]

As far as I am aware as long as the diameter (I mean cross sectional area) of the cable exceeds the requirements then the only factor that matters is that the energy withstand time of the cable (i.e.70 degree or 90 degree etc) makes any difference in your calculations. Obviously that excludes mechanical protection.

 

[markthespark77]

thanks guys , you learn all the time, I never knew you could use flex for hard wiring ( guilty gulp for years advised wrongly ! )

 

[manchesterman]

My niceic inspector told me that you couldn't on the 16th edition but this changed on the 17th hence all the plug and play lighting now being used in commercial/retail. I had questioned it and he said it's ok as long as it's correctly sized/fused etc. i couldn't quote the reg no's though

 

[derek preece]

I only use flex, personaly, for the last connection to the load usually otherwise it's just twin and earth (or armoured/mi).

 

[markthespark77]

Ok thanks a lot !

 

[johnboy6083]

I don't see a problem using flex, as long as its suitable for conditions ect.

 

[Guitarist]

Just make sure that you label up any plug where the appliance is not obvious. No problem with flex at all, as others have said.

 

[MarkieSparkie]

Flexible cables can be used for fixed wiring in certain circumstances, you should read BS7671:2008+A1:2011 521.9 group of regulations for details.

 

[MarkieSparkie]

My niceic inspector told me that you couldn't on the 16th edition but this changed on the 17th hence all the plug and play lighting now being used in commercial/retail. I had questioned it and he said it's ok as long as it's correctly sized/fused etc. i couldn't quote the reg no's though

Oh dear! Yet another example of an NICEIC inspector not knowing the regulations.

Flexible cables were permitted to be used under the 16th edition of the Wiring Regulation for fixed wiring in certain circumstances, where BS7671 521-01-04 applied.

In fact the regulations have become tighter (like most things) under the 17th edition, placing additional limitations on the use of flexible cable for fixed wiring, where BS7671:2008+A1:2011 521.9 group of regulations apply.

 

[steve_morrison]

nothing wrong with flex if installed correctly

 

[Guitarist]

Some flex cables are obviously not meant for mains voltage, and some do not have the outer sheath required for fixed wiring. As you are talking about mains flex with an outer sheath, then it will be just as suitable as T&E if of the correct type and rating.