Running 6mm twin & earth cable.

[DiyPete]

Hi, just to say my garage has a single entry up and over door and I will not be running the cable over it. Should the trunking/conduit melt in a fire, there are wall cupboards and shelving just below the run. I am still deciding between 25mm conduit or 25mm x16mm trunking for the run both I calculate will take less than 30% of the area inside them. With trunking, I am concerned about the 90-degree bends with 6mm T&E unless I create 45- degree bends,  either way, I want to make a neat job of it even if it is only a garage. What do you think?

Thanks

Pete

 

[Fleeting]

The cable must be supported to prevent premature collapse in the event of a fire, suggesting cupboards and shelving will "catch" it is not acceptable. 

 

[Murdoch]

I think you need to read all the Notes as opposed to just Note 1 then it will be clear that suitable support is required not just on escape routes and/or stairwells.

Still not convinced that's what this reg says ., it does include the classic "shall" ....... that said I always do use the correct method but many don't

If the sentence started "All" then I would agree with you

 

[Sidney]

Yet another regulation that can be read both ways and is ambiguous. TBH I just use fire clips anyway as they help support the cable and trunking when the glue eventually gives up and it peels away from the wall.

 

[binky]

when the glue eventually gives up and it peels away from the wall.

I never rely  on the adhesive strip, it makes it easier to get trunking up on the wall, but I then drill and fit a few plugs and screws to make sure it stays there ad infinitum. A long run of 6mm is heavy enough to pull sticky back off anyway. 

 

[Murdoch]

I never rely  on the adhesive strip, it makes it easier to get trunking up on the wall, but I then drill and fit a few plugs and screws to make sure it stays there ad infinitum. A long run of 6mm is heavy enough to pull sticky back off anyway. 

That's what the adhesive is for isn't it! 

That said you see so many falling off the walls so we must be in the minority and once the wall plug is in then its so easy to add the metal clips!

 

[Geoff1946]

I've yet to find an adhesive tape which doesn't give up when under continuous strain; I'm thinking stick on hooks, cable tie bases, etc, as well as electrical trunking. 

Put it under pressure, with a screw through and it continues to hold well, but on its own its useless.

Same applies to self adhesive velcro too.

 

[binky]

That's what the adhesive is for isn't it! 

That said you see so many falling off the walls so we must be in the minority and once the wall plug is in then its so easy to add the metal clips!

They just don't make paint that sticks to walls properly these days  :^O .

Using the metal clips would make installing the cable easier whilst firking about trying to get the lid on.

Notes 1-4 above are just saying where 'egress protection' is needed, and clarifying methods of achieving this. As I read it, I think I'm still right in thinking that this does not apply to all situations where cables are run in trunking along walls and ceilings, although there would certainly be no harm in using fire clips.

 

[Murdoch]

Notes 1-4 above are just saying where 'egress protection' is needed, and clarifying methods of achieving this. As I read it, I think I'm still right in thinking that this does not apply to all situations where cables are run in trunking along walls and ceilings, although there would certainly be no harm in using fire clips.

that’s how I read it

just another example of a very poorly worded ref and quite how people think it says that all cables in all locations need metal clips is beyond me

the muppets who write the regs need to get revisions to the regs or new regs proof read by the Plain English Society before they go to draft print

 

[Fleeting]

that’s how I read it

just another example of a very poorly worded ref and quite how people think it says that all cables in all locations need metal clips is beyond me

the muppets who write the regs need to get revisions to the regs or new regs proof read by the Plain English Society before they go to draft print

Have you not considered the difference between the 17th and 18th Ed changes whereby the 17th clearly indicates escape routes as a header, the 18th does not. This was much discussed prior to the release of the 18th Ed as one of the major changes.

 

[Murdoch]

Have you not considered the difference between the 17th and 18th Ed changes whereby the 17th clearly indicates escape routes as a header, the 18th does not. This was much discussed prior to the release of the 18th Ed as one of the major changes.

yes, but the 18th edition hasn’t made it any clearer ....

 

[Fleeting]

yes, but the 18th edition hasn’t made it any clearer ....

It is perfectly clear in both editions. Don't be offended maybe you should switch your default setting that the IET are muppets or idiots which probably clouds your judgement and consider what the Regulation is saying.

 

[Murdoch]

It is perfectly clear in both editions

we better agree to disagree because it’s a clear as mud, in both

please tell me you didn’t contribute to the 18th edition wording

 

[Fleeting]

we better agree to disagree because it’s a clear as mud, in both

please tell me you didn’t contribute to the 18th edition wording

Whether I did or did not will not change your opinion of the Regulations. 

 

[Murdoch]

Whether I did or did not will not change your opinion of the Regulations. 

so you did then 

so many regulations are written poorly and open to interpretation - all the families affected by Grenfell know all about this

 

[Fleeting]

so you did then 

so many regulations are written poorly and open to interpretation - all the families affected by Grenfell know all about this

I assume you accept the Regulation regarding consumer units in a dwelling whereby it shall be constructed from non-combustible materials or enclosed in such or words to that effect. This I assume you see no ambiguity with however, Regulation 421.1.201 cites the word "shall" which you have previously stated is not as definitive as "all" but you accept this Regulation? 

 

[binky]

This was much discussed prior to the release of the 18th Ed as one of the major changes.

 there are so many discussions when regs change and little concensus / precise guidance given afterwards,  so it's easy to miss many subtleties.   

Now, I've dug the regs book out and see what you mean about 'shall'  and the changes to the section  headings. However, that leaves a nice can of worms of what is the definition of 'premature collapse' ?

It is considered good practice to install cable clips with the nail below the cable - so is the nail good enough to support a cable in a fire? PVC trunking and conduit is fire retardent as I understand it, so would they support a cable long enough to prevent 'premature collapse' if not installed in an egress route as per Note1? 

 

[Murdoch]

 This I assume you see no ambiguity with however, Regulation 421.1.201 cites the word "shall" which you have previously stated is not as definitive as "all" but you accept this Regulation? 

shall yes, but then cites examples which to most people means in the examples given it shall be done and in where the examples aren’t relevant it doesn’t need to be done

 

[Murdoch]

Now, I've dug the regs book out and see what you mean about 'shall'  and the changes to the section  headings. However, that leaves a nice can of worms of what is the definition of 'premature collapse' ?

This is interesting - AND surely that wording should be in the actual regulation - I mean how many people reach for the regs (especially newly qualified) and bother to review the changes section.

For the record I always the correct clips irrespective of the location

I will continue to have little respect for the editors of the regs

 

[Fleeting]

This is interesting - AND surely that wording should be in the actual regulation - I mean how many people reach for the regs (especially newly qualified) and bother to review the changes section.

For the record I always the correct clips irrespective of the location

I will continue to have little respect for the editors of the regs

Aside from being an electrician I also work in fire safety and whilst buildings have defined escape routes it has been argued that almost anywhere in a building could be included as an escape route, defined or not. If you are in a toilet, kitchen or anywhere and an evacuation situation occurs then the footfall from your location can be deemed your escape path.