Rating of lighting cable (1mm & 1.5mm)

[martind]

Ok, my first question(s)
What is the max current for 1mm & 1.5mm cable respectively? (I am trying to workout if there are two many lights on the same lighting circuit).

 

[trev]

It's not as simple as "This csa cable can take this current"
Lot's of factors lower the ccc of a cable such as grouping, running in insulation, thermal effects etc.

 

[Farmelectrics]

If its clipped direct 1.5 is 19a and 1mm is 16a I think haven't got reqs handy but it's as good as damn it

 

[Guest123]

Many installation factors need to be considered before an accurate decision is made.

What size protective device is protecting the 1.0mm t&e??

 

[Farmelectrics]

Your right Lenny just trying to give a guide to are man

 

[Guest123]

My post wasn't a direct reply to yours mate, just trying to coax a bit more info out of the OP.:Mr-T:

 

[kingeri]

1.5mm is 20a, 1mm is 16a but only when clipped direct. There are, of course, as already mentioned, other factors to consider relating to the installation method. However, as lighting circuits are usually protected by a 6a protective device, there is USUALLY ample capacity to play with using either. For example, when 1mm is run in thermal insulation, the current carrying capacity is halved, but still exceeds the 6a breaking capacity of the protective device. Normally,you don't want to be exceeding 6a on a lighting circuit - you'd have to go out of your way to derate the cable below this.

 

[Farmelectrics]

Yes I no that Lenny no probs mate

 

[martind]

You guys are really fast to respond! Thanks.
I am referring to flat twin & earth. I do not know what the term “clipped” means (but hopefully will do in a few mins.
After a brief inspection at the CU it has been observed that the lighting circuit cable has been put in to a 16 amp breaker. It was also discovered that there are 11 lights on the circuit (maybe it was tripping when in the 6amp breaker)

 

[Octopus]

If I were you, and wanted piece of mind, give a local sparky a call and ask for his advice when actually looking at the CU/house electrics.

You'll get lots of opinions here but there's nothing like looking at the actual installation.

 

[Farmelectrics]

Sounds like you need a qualified electrician

 

[kingeri]

You guys are really fast to respond! Thanks.
I am referring to flat twin & earth. I do not know what the term “clipped” means (but hopefully will do in a few mins.
After a brief inspection at the CU it has been observed that the lighting circuit cable has been put in to a 16 amp breaker. It was also discovered that there are 11 lights on the circuit (maybe it was tripping when in the 6amp breaker)

That is BAD. The cable is likely to not be adequately protected. Plus, the light switches and pendants, junction boxes etc. will probably only be rated up to 6a. Get an electrician in to sort it out. Please.

 

[telectrix]

agree. if, say 1.5mm cable is rated at 16A clipped direct, where there is adequate cooling, then if it is then smothered in that horrible 12" of itchy -poo, then it's rating is down by about 50% to 8A. even a 6A MCB will happily stay closed at this level of current for ever and a day, so the answer to the insulation lies in the attached pic.

 

[tout2007]

For firm and accurate information (not only for this case, but also for any doubt about the proper selection of wire/cable size), you need to refer to the BS Standard as well as the manufacturer catalogues and datasheets. There are many factors affecting the "Current Carrying Capacity" of any wire/cable such as but not limited to:

1. Ambient/ground Temperatures.
2. Type and size of conduits, cable trays, etc.
3. Installation method.
4. Other wires/cables in the same conduit.
5. Earthling system.
6. Protection scheme.

 

[kingeri]

For firm and accurate information (not only for this case, but also for any doubt about the proper selection of wire/cable size), you need to refer to the BS Standard as well as the manufacturer catalogues and datasheets. There are many factors affecting the "Current Carrying Capacity" of any wire/cable such as but not limited to:

1. Ambient/ground Temperatures.
2. Type and size of conduits, cable trays, etc.
3. Installation method.
4. Other wires/cables in the same conduit.
5. Earthling system.
6. Protection scheme.

As opposed to the extra-terrestrial system? :joker:

 

[telectrix]

do extra terrestrials us vulcanised rubber cable?

 

[tout2007]

Sorry my friends . . It
is a typing mistake. . I meant Earthing System (TNS, TNC, IT…..) and not
Earthling . .

 

[telectrix]

we all know that. just well done for hawkeye, kingeri for spotting it.

 

[malcolmsanford]

Not sure whether Earthling or Earthing, how what system you have would effect the current carrying capacity of a cable ...........................

 

[Darkwood]

Not sure whether Earthling or Earthing, how what system you have would effect the current carrying capacity of a cable ...........................

I would suspect hes hinting on ELI results but agree with regards to this situe its going to hard to not meet required ELI in domestic even on a large house with regards to lighting regardless of the Supply type.