IET logo
 
IET
Decrease font size
Increase font size
Topic Title: These new fangled ideas!
Topic Summary: 1.5mm lighting cable & feeds to switches
Created On: 09 February 2013 06:50 AM
Status: Post and Reply
Linear : Threading : Single : Branch
<< 1 2 3 Previous Next Last unread
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 10 February 2013 04:58 PM
User is offline View Users Profile Print this message


Avatar for Martynduerden.
Martynduerden

Posts: 3211
Joined: 13 July 2008

Originally posted by: daveparry1

Using the chaser in an empty house is ok Martyn, I often use the 4 inch angle grinder and make 4 cuts then chisel out the centre , but in an occupied house (which most of my work is) it just creates too much dust,

Dave.


I think you might need a better vacuum/chaser Dave...

I use the Metabo MFE30 & the Festool ct26l almost dust free.

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com
 10 February 2013 05:44 PM
User is online View Users Profile Print this message



daveparry1

Posts: 6162
Joined: 04 July 2007

Both way out of my price range for the amount of use i'd give them Martyn!

Dave.
 10 February 2013 06:46 PM
User is offline View Users Profile Print this message



gordon.s1

Posts: 104
Joined: 20 September 2001

Why continue with 1.5mm cable when 1mm lighting rings are much better at least cable fits in these new ceiling roses.
Also recommend changing 12v and GU10's to LED,s, there are dimmers that work .5% to full.

-------------------------
Helping others today enables
others to help you tomorrow.
 10 February 2013 07:26 PM
User is online View Users Profile Print this message



daveparry1

Posts: 6162
Joined: 04 July 2007

How often do you come across lighting "rings" then Gordon?
 10 February 2013 07:39 PM
User is offline View Users Profile Print this message


Avatar for Martynduerden.
Martynduerden

Posts: 3211
Joined: 13 July 2008

Originally posted by: daveparry1

How often do you come across lighting "rings" then Gordon?


I have seen them only once and it was up north about 12 years ago!

Like I sad previously its about time we stopped wiring switches and the like with t&e smart wiring has to be the future.

Then we could use 1.0mm for most lighting applications...

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com
 10 February 2013 08:12 PM
User is offline View Users Profile Print this message



Zs

Posts: 2853
Joined: 20 July 2006

Ha, been on any courses lately Mart?

Zs
 10 February 2013 08:16 PM
User is offline View Users Profile Print this message


Avatar for Martynduerden.
Martynduerden

Posts: 3211
Joined: 13 July 2008

Originally posted by: Zs

Ha, been on any courses lately Mart?

Zs


You know me well enough to know a recent course is only the tip of the iceberg I've been banging this drum for ages

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com
 10 February 2013 09:10 PM
User is offline View Users Profile Print this message



Zs

Posts: 2853
Joined: 20 July 2006

Pulling your leg Mart. I admire you for keeping so far ahead of the game.
 11 February 2013 06:49 AM
User is offline View Users Profile Print this message


Avatar for ebee.
ebee

Posts: 5672
Joined: 02 December 2004

"Using the chaser in an empty house is ok Martyn, I often use the 4 inch angle grinder and make 4 cuts then chisel out the centre , but in an occupied house (which most of my work is) it just creates too much dust,

Dave."

Ditto on that one Dave.

Martyn, I find that scutches do alter position over time and a sideways tap back with hammer now and again is called for, never had them sliding out as such though. A design with a groove in the holder at 90 degrees to the vee and a raised rib on the blade to correspond would cure sideways movement but probably put the cost up greatly.

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 11 February 2013 06:59 AM
User is offline View Users Profile Print this message


Avatar for ebee.
ebee

Posts: 5672
Joined: 02 December 2004

"Originally posted by: daveparry1

How often do you come across lighting "rings" then Gordon?


I have seen them only once and it was up north about 12 years ago! "

Martyn, I would suspect the bloke that wired that lighting ring was the one who famously cut his house in half!

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 11 February 2013 08:17 AM
User is offline View Users Profile Print this message



broadgage

Posts: 1282
Joined: 07 August 2007

Originally posted by: gordon.s1

Why continue with 1.5mm cable when 1mm lighting rings are much better at least cable fits in these new ceiling roses.

Also recommend changing 12v and GU10's to LED,s, there are dimmers that work .5% to full.


1.5mm is almost a requirement now, there is no regulation that says "thou shalt wire lighting circuits in 1.5mm" but it is inceasingly demanded or expected.
1.5mm is now the minimum for power circuits, and it has been seriously suggested that the connection of an extract fan, shaver socket or bell transformer to what would normally be considered a lighting circuit renders it a power circuit that must therefore be wired in 1.5mm.

A fair proportion of domestic lighting lighting circuits supply bell transformers, extract fans or shaver outlets.

It seems likely that future regulations will require 1.5mm for lighting, and that use of the larger cable now will future proof installations.
Although regulations are not intended to be retrospective they are increasingly enforced thus. Many relatively new homes wired by approved electricians would now merit an "unsatisfactory" report on a formal inspection and would require expensive works in order to be rented out for example.

And BTW it is not the norm to wire lighting circuits in a ring !
Drifting a bit O/T, I normally wire ELV lighting in an off grid home as a ring in order to reduce voltage drop, but see little merit for mains voltages.
 11 February 2013 10:50 AM
User is offline View Users Profile Print this message



topmark

Posts: 125
Joined: 27 March 2009

with the wide use of led lighting becoming the norm in the domestic sector i would envisage greater use of 1mm.
if you do the calcs,1.5mm can be an unnecessary expense.

especially when installs have more than the traditional one up,one down lighting circuits,thereby keeping v/drop,circuit lengths pretty short etc.
if designed and planned properly,1mm can be widely used whilst still complying with regs etc
 11 February 2013 12:51 PM
User is offline View Users Profile Print this message



broadgage

Posts: 1282
Joined: 07 August 2007

Originally posted by: topmark
with the wide use of led lighting becoming the norm in the domestic sector i would envisage greater use of 1mm.
if you do the calcs,1.5mm can be an unnecessary expense.
especially when installs have more than the traditional one up,one down lighting circuits,thereby keeping v/drop,circuit lengths pretty short etc.
if designed and planned properly,1mm can be widely used whilst still complying with regs etc


In theory, I agree entirely, but in practice 1.5mm seems to be becoming a requirement "by the back door"
 11 February 2013 04:21 PM
User is offline View Users Profile Print this message


Avatar for ebee.
ebee

Posts: 5672
Joined: 02 December 2004

1.0 T & E could be considered safer by some in an earth fault scenario than 1.5 T & E because of the R1/R2 equation!.

What`s to say you must not ring a 1.0 lighting circuit if you like to?I know someone who used to do just that and I think Maryn probably saw one of his jobs a bit back.

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 11 February 2013 07:55 PM
User is offline View Users Profile Print this message



Zs

Posts: 2853
Joined: 20 July 2006

Broadgage, your post from this morning is really interesting.

I don't agree with you on all of it but I can see where you are coming from. I'm curious as to your sources but that's by the bye.

I agree that 1.5 is the standard for most but I'm not agreeing with it being a reg coming in via the back door. Rather, I think it is the option for those who don't bother to calculate. As soon as you begin to check your circuits you realise that 1mm is going to do the job just as well. Give or take de-rating caused by an insulation sandwich.

So, If you encounter 1mm blue and brown in a DB these days, you are probably encountering the work of someone who knows what they are doing. Or someone who has just forgotten what they came upstairs for.

As for the bell transformer......I'd not be too worried about that in 1mm, would you?

Zs
 11 February 2013 10:11 PM
User is online View Users Profile Print this message



daveparry1

Posts: 6162
Joined: 04 July 2007

Agreed Zs and as most lighting circuits (domestic) are on 6 amp breakers 1.00mm is well whithin spec,. even if it was surrounded by insulation and needed de-rating. It's a bit like people who say they always use 10.00mm for showers and cookers, totaly unnecessary in most cases,

Dave.
 12 February 2013 08:31 AM
User is offline View Users Profile Print this message



broadgage

Posts: 1282
Joined: 07 August 2007

Originally posted by: Zs

Broadgage, your post from this morning is really interesting.



I don't agree with you on all of it but I can see where you are coming from. I'm curious as to your sources but that's by the bye.



I agree that 1.5 is the standard for most but I'm not agreeing with it being a reg coming in via the back door. Rather, I think it is the option for those who don't bother to calculate. As soon as you begin to check your circuits you realise that 1mm is going to do the job just as well. Give or take de-rating caused by an insulation sandwich.



So, If you encounter 1mm blue and brown in a DB these days, you are probably encountering the work of someone who knows what they are doing. Or someone who has just forgotten what they came upstairs for.



As for the bell transformer......I'd not be too worried about that in 1mm, would you?



Zs


A bell transformer on 1.0mm would, from a practical point of view, worry me not in the least and I would be happy to install it thus for my own use, the load is far less than any common lamp.
Nevertheles, regulations now require at least 1.5mm for power circuits and a pedantic inspector would argue that a bell transformer is not a light, and that the circuit to which it is connected is therefore a power circuit.
Similar arguments could be applied to extract fans, shaver outlets, and electric clocks, none of these are lights but are often connected to what used to be called lighting circuits, and might be called power circuits now and therefore need 1.5mm.

If an inspector argues that "two circuits into a single MCB" merits an unsatisfactory report, then I can imagine pedantic persons arguing that a "power circuit in 1.0mm" is at least as bad.

And yes I am aware of a case of a mortage being refused due to "unsatisfactory electrical installation" the fault being a bell transformer on 1.0mm. The householder had been qouted several hundred pounds to rectify the fault.
I removed the bell transformer and installed a battery doorbell !
 12 February 2013 08:37 AM
User is offline View Users Profile Print this message


Avatar for ebee.
ebee

Posts: 5672
Joined: 02 December 2004

"Nevertheles, regulations now require at least 1.5mm for power circuits"

What Regulation is that?

What is the definition of a "power circuit" ? not in BS 7671

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 12 February 2013 09:10 AM
User is offline View Users Profile Print this message


Avatar for Rulland.
Rulland

Posts: 461
Joined: 11 April 2008

What about security alarms on the rad?, I never do it, but have argued why other people do on the security forums, their reasoning being its fused down to 3 amps at the spur what's the problem?.
Also that shavers, power showers!, 500w floods, extract fans, all are added as well.
Anyone think of valid reasoning why alarms shouldn't be tapped of a lighting rad? (I have my own btw).

-------------------------
Those who make no mistakes do very little work!!......
 12 February 2013 09:41 AM
User is online View Users Profile Print this message



daveparry1

Posts: 6162
Joined: 04 July 2007

No reason at all that I can see Rulland, I think some people are taking words from "the red book" too literally, (nothing new there!) what it actually shows on a table in there somewhere is that 1.00mm t/e is to be used for lighting circuits only, my way of thinking is that if an alarm or fan etc. is fed from a lighting circuit it's still a lighting circuit!

Dave.
IET » Wiring and the regulations » These new fangled ideas!

<< 1 2 3 Previous Next Last unread
Topic Tools Topic Tools
Statistics

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2014 FuseTalk Inc. All rights reserved.