IET logo
 
IET
Decrease font size
Increase font size
Topic Title: Multi-gang extensions
Topic Summary: Are multi-gang extension leads accepted as permanent wiring solutions
Created On: 26 February 2014 11:55 PM
Status: Post and Reply
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 26 February 2014 11:55 PM
User is offline View Users Profile Print this message



Pete2131

Posts: 1
Joined: 26 February 2014

Good evening fellow members,

Apologies if this appears a daft question or has been answered before, new to the forum. During recent safety audits and fire risk assessments, I have come across numerous electrical installations for IT systems, TV aerial systems, etc. whereby the power leads for the equipment have been connected to multi-gang extension leads either plugged into a socket or connected to a spur. Is this an accepted and approved method of installation or should proper sockets be installed for each plug (most are plugs with inbuilt transformers steeping the voltage down from 240V to about 12V).

Any advice will be greatly appreciated. Many thanks in advance.
 27 February 2014 08:09 AM
User is offline View Users Profile Print this message


Avatar for dickllewellyn.
dickllewellyn

Posts: 1222
Joined: 19 March 2010

It depends entirely on the purpose they are used for Pete. A bunch of IT equipment would be less of an issue than a bunch of freezers or a couple of heaters for example.

It is always nice to try and mitigate the need for extension leads and adapters by installing sufficient numbers of sockets, but multi gang leads can be a useful solution. Many IT professionals use leads with surge arresters built in which is a benefit in that instance. There is of course a difference between short meet multi gang leads in use in a single area for controlled low powered equipment and long leads snaking all over the place with indiscriminate equipment in use.

-------------------------
Regards
Richard (Dick)

"Insert words of wisdom and/or witty pun here"
 27 February 2014 09:01 AM
User is offline View Users Profile Print this message



anastasis

Posts: 588
Joined: 01 September 2009

I agree with Dick that they should be avoided, but in many cases it is impractical or expensive to install fixed sockets for everything.

I'd suggest reg 133.3 is a useful guide. For low-current equipment in low-risk environments, it would be difficult to argue that there's anything inherently dangerous about using 4-way adaptors etc. The fact that a better solution is possible (at increased cost) does not necessarily mean the cheap and cheerful approach is not allowed.

This question often arises because H&S people read things that say "don't use multiway adaptors as they can overload sockets" and start panicking when they see half a dozen little power supplies plugged into a six-way block, because they don't realise that the total load is just a fraction of an amp.

I like to encourage people to use quality power strips from the likes of Olson for this type of application, but there's a cost implication which generally puts them off.
 27 February 2014 10:28 AM
User is offline View Users Profile Print this message



broadgage

Posts: 1356
Joined: 07 August 2007

IMHO, multiway extension leads are often of poor qaulity, and cant be trusted to carry 13 amps.

As others post, with even a little common sense they are fine for large numbers of small loads as are often found in the modern office.

My view is that they should be fitted with fuses no larger than 7 amps in order to provide a safety margin.
If the 7 amp fuse blows in normal use, than additional permanent outlets are required for the larger load(s).
I must stress though that is my personal view and not a regulatory requirement.

If a couple of 2KW or 2.4KW heaters are plugged into a 4 way lead, then in theory a 13 amp fuse should blow before any harm is done. In practice the multiway sockets are liable to melt before the fuse blows.
A 7 amp fuse would blow in time, and is ample for say a PC, desk lamp, a display screen, and cellphone charger.
 27 February 2014 11:15 AM
User is online View Users Profile Print this message


Avatar for OMS.
OMS

Posts: 19895
Joined: 23 March 2004

In the floor void under my desk is a 32A Three Phase and Neutral dual earth busbar.

There is a 32A unfused tap off, plugged in that feeds (via a 4 core flex in metallic flexible conduit) a 4 way power bar that also has a a further 4 way bar plugged in - each bar is fused at 13A

These sit in a cable dump under my desk and the supply lead enters the floor void via a cable grommet in the floor.

There are probably 1200 exactly like it in the building and we have no reservations regarding the approach - we designed it that way for flexibility.

So, the answer regarding the use of power bars is, as always, "that it depends" - if it's reasonably well engineered, then the use of power bars instead of large numbers of fixed sockets, is perfectly acceptable - in other cases, it will cause additional potential hazard.

Regards

OMS

-------------------------
Failure is always an option
 27 February 2014 12:19 PM
User is offline View Users Profile Print this message



AdrianWint

Posts: 270
Joined: 25 May 2006

Personally, I prefer that wallwarts & the like are plugged into extension leads!

I've never seen a wallwart which incorporates any find of fuse in the 230V side. If they are plugged into 'fixed' socket outlet then the next protective device tends to be the 32A MCB upstream.... If they are plugged into a 4-way then the protective device will be a 13A fuse or maybe lower.......
 27 February 2014 01:46 PM
User is offline View Users Profile Print this message



allaway

Posts: 101
Joined: 08 July 2007

Originally posted by: AdrianWint

Personally, I prefer that wallwarts & the like are plugged into extension leads!



I've never seen a wallwart which incorporates any find of fuse in the 230V side. If they are plugged into 'fixed' socket outlet then the next protective device tends to be the 32A MCB upstream.... If they are plugged into a 4-way then the protective device will be a 13A fuse or maybe lower.......


I love the term "Wallwart" - I have used it for years!

I have seen a few - probably 1% or less with an accessible fuse but a majority are missing them. Over the years I have taken a few failed ones apart and they can be split into three - thise without fuses, those with a normal wire fuse on the incoming circuit and those with a thermal/resettable fuse.

Unfortunately there is no way to know which are fused and which are not - so I too like to see them in a fused extension block albeit 13A.
 28 February 2014 08:48 PM
User is offline View Users Profile Print this message



weirdbeard

Posts: 1652
Joined: 26 September 2011

Originally posted by: AdrianWint

Personally, I prefer that wallwarts & the like are plugged into extension leads!



I've never seen a wallwart which incorporates any find of fuse in the 230V side. If they are plugged into 'fixed' socket outlet then the next protective device tends to be the 32A MCB upstream.... If they are plugged into a 4-way then the protective device will be a 13A fuse or maybe lower.......


Although the numbers seem right on paper in reality the 32A mcb will go possibly aswell, if not rather than the 13A fuse!
 28 February 2014 10:15 PM
User is offline View Users Profile Print this message


Avatar for stateit.
stateit

Posts: 2227
Joined: 15 April 2005

They are only acceptable when I use them.

The above stands true for myself, and every one else it seems.

For commercial users I ask (write) that all such leads are inspected regularly (there's usually some monthly meeting that this can be fitted into) and a tickbox checked against any signs of scorching, frayed leads, other damage.

In my mind (rightly or wrongly) that mitigates me against any untoward lingering problems and keeps them aware of the issues.

-------------------------
S George
http://www.sg-electrical.com
 28 February 2014 10:33 PM
User is offline View Users Profile Print this message



peteTLM

Posts: 3231
Joined: 31 March 2005

There is a big difference between a 'power bar' made by say olsen, and a cheap 4 gang extention lead from the nearest shed.

IT cabinets and good quality desks often have items from the upper end of the market, and not such a flimsy approach. More of a flexible solution to items that might be moved slightly and require a flexible interconnection, or a user friendly method of installation .

I dont see any problem with low power items, especially where its impractical to provide multiple sockets provided by fixed building wiring, just to provide a few plug in psu;s.

-------------------------
----------------------------------------
Lack of planning on your part doesn't make it an emergency on mine....

Every man has to know his limitations- Dirty Harry
 28 February 2014 11:36 PM
User is offline View Users Profile Print this message



AdrianWint

Posts: 270
Joined: 25 May 2006

Originally posted by: weirdbeard

Originally posted by: AdrianWint



Personally, I prefer that wallwarts & the like are plugged into extension leads!







I've never seen a wallwart which incorporates any find of fuse in the 230V side. If they are plugged into 'fixed' socket outlet then the next protective device tends to be the 32A MCB upstream.... If they are plugged into a 4-way then the protective device will be a 13A fuse or maybe lower.......




Although the numbers seem right on paper in reality the 32A mcb will go possibly aswell, if not rather than the 13A fuse!


Indeed, the discrimination isn't guaranteed but it still gives me a nice warm feeling. The 4ways at home which run the coms cabinet (router, cable modem, NAS box etc) running unattended 24/7 all have 2A fuses in them :-)
 01 March 2014 11:49 AM
User is offline View Users Profile Print this message


Avatar for dickllewellyn.
dickllewellyn

Posts: 1222
Joined: 19 March 2010

I have two 4 gang bars behind my TV, both with 10amp fuses from the factory (I just checked!) and cost less that a fiver each. These are both plugged into a mostly unwound 8 meter 2 gang reel which runs along the skirting to the nearest socket across the room and behind the sofa. In my defence, the reel does have a thermal cutout, and I am below the fully wound rating, but I would still chastise my customers for doing such a thing!

-------------------------
Regards
Richard (Dick)

"Insert words of wisdom and/or witty pun here"
Statistics

See Also:



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