Flex for fixed wiring

[charlie76]

Would you suggest flex for fixed wiring on an EICR is a C3? The client has basically run flex from one socket to a surface socket (i.e. a glorified extension lead). However I would say this is fixed wiring.

What does 521.9.1 mean where it states "only where the the relevant provisions of the regulations are met"? Does this mean CCC, installation method, overload protection etc.

 

[Pete999]

Hello All,

Hopefully this question will be sufficiently related to the OP`s thread to be allowable:

With regard to Flex cable being used for `Fixed Wiring` - I think that I know that it is NOT allowed by the Electrical Regulations - certainly not to be run under floors of in stud walls etc.

However for Years quite a few Heating systems that I have installed where the Boiler had a Pump over-run with the Pump having to be wired to the Boiler and also 4 core cable required `to the Boiler` has had the Boiler supply cable and the Pump cable run [usually from the Cylinder cupboard] in Heat Resistant Flex [`re. connecting to the Boiler`] - by the Electricians that have carried out the Heating Controls wiring.

The Flex would definitely have been run both under floors and within stud walls to get from the Cylinder cupboards to the Boilers.

I have queried this on various occasions - asking whether the Boiler 4 core [inc. Earth] and the Pump 3 core [inc. Earth] should be run from the Cylinder cupboard / Wiring Centre in Flat cable to adjacent the Boiler and then `transition` from Socket boxes to Heat Resistant Flex - exiting through flex entry / exit plates to connect to the Boiler.

I have usually been on friendly terms with the Electricians so there has been no perceived animosity / bad feelings about me asking that.

However this was almost universally rejected by the various Electricians that wired my Heating systems - and those Electricians would have issued Certificates for the whole Property`s Electrical installation including the Heating Controls.

What I described about flat cable being used from the Cylinder cupboard to adjacent the Boiler and then transitioning to Heat Resistant Flex was done by at least one of the Electricians over the Years and He stated that I was correct to expect that the Heating Controls wiring was installed in that way.

Sorry for the long preamble - my question is:

If as I suspect what I described about the Fixed wiring is the correct way / the only correct way [?] why would at least 6 or 7 Electricians use Flex without any hesitation [and after being asked about it by me] for the `fixed wiring` section of the Heating System Controls - knowing that they had to Certify the whole Electrical Installation - usually a complete Re-wire & Consumer Unit and the Heating controls - ?

Chris

Your post may be disputed by some members regarding flex used for fixed wiring Chris.

 

[Octopus]

Interesting timing ...........over in the plumbers forum I have just said that as far as I'm concerned boiler wiring is "control" wiring and therefore use of 5 core "flex" is perfectly acceptable......

off to my bunker now with tin hat on!

 

[Adj]

as far as I'm concerned boiler wiring is "control" wiring and therefore use of 5 core "flex" is perfectly acceptable......

 

[Adj]

Absolutely agree - LV control cable

 

[chris murphy]

Your post may be disputed by some members regarding flex used for fixed wiring Chris.

Hello Pete,

I thought that because the OP of this thread was asking for opinions about Flex having been used to connect Socket outlets that what I have asked was `close enough` - however reading back I admit that You are probably right that I should have created a separate thread to ask my question.

Regarding the Original thread message / question:

With my VERY Limited Electrical Training / `knowledge` - am I remembering correctly that Flex is allowable where `it is visible throughout its entire length` [words to that effect] - obviously fixed correctly ?

However I am guessing that there might well be a `length limit` that I am not remembering ?

I am NOT `trying to be clever` / trying to undermine Members replies with these questions - I would genuinely like to know whether I have remembered that point correctly ?

Regards,

Chris

 

[Dave OCD]

When wiring system boilers with zone valves etc at a different location I always use twin and/or three core and earth between the locations then change to h/r flex adjacent to the final connections.

 

[Ian1981]

The regulations do indeed allow flex to be used as fixed wiring as long as it’s the heavy duty type unless the risk of damage during installation is low etc etc, types of flexes are given in bs en 59565-1
For more detail see regulation 521.9.1 page 126 of bs7671.

 

[chris murphy]

Interesting timing ...........over in the plumbers forum I have just said that as far as I'm concerned boiler wiring is "control" wiring and therefore use of 5 core "flex" is perfectly acceptable......

off to my bunker now with tin hat on!

Hello Murdoch,

Thanks for your Expert opinion - I am pleased that you would be happy for Flex to be used to wire Heating System Controls / `Controls Wiring`.

Although as I mentioned Electricians carried out the wiring on my Heating systems - usually because the Builder / Customer always wanted only ONE Electrical Contractor / Electrician certifying the whole property`s Electrical Installation - and therefore the wiring was `nothing to do with me` - I still was not completely happy that `My System` had been wired correctly.

I am also pleased to see Member Dave OCD`s message describing what I described as a method that I would have liked to have seen done.

So after many Years although I had no responsibility for the wiring on most systems [since 2005] I am reassured that both methods are acceptable - "Thanks".

Regards,

Chris

 

[chris murphy]

The regulations do indeed allow flex to be used as fixed wiring as long as it’s the heavy duty type unless the risk of damage during installation is low etc etc, types of flexes are given in bs en 59565-1
For more detail see regulation 521.9.1 page 126 of bs7671.

Hello Ian1981,

Thank You very much for the information.

Would you guess that if the Flexes that I have described were `BS Heat Resistant Butyl` it would be likely to be `Good Quality` / `Heavy Duty` ?

I would never have known the specific BS / EN Numbers.

I would value your opinion please.

Regards,

Chris