Daisy Chaining electrical extension/multiboxes etc

[kearton]

Common sense says it's dangerous. But is it illegal? I'm trying to find some documentation which confirms this. I can find information on the web relevant to the USA, but not the UK. (e.g in the USA it's illegal to plug a multibox into another one. It's also illegal to use *one* for more than 90 days (i.e they're for temporary use only etc))

 

Can anyone point me in the right direction for UK-specific info please?

[Ric_]

I believe that such a setup would not pass an electrical inspection... the sight test part alone!!!

[kearton]

Yes, but is there documentation somewhere which clearly states this?

I thought I was getting close looking around the HSE website, but nothing concrete thus far...

[Joedetic]

It's a bad idea because the cable used in each splitter socket (or whatever you want to call it) is only designed to take the load of however many devices can be plugged into it (ie 2, 4, 6 etc)

 

If you were to chain a second 4-socket splitter into the first one, and had devices plugged into all of the free sockets (so 7 devices) you're likely to overload the max. power rating for the cable in the first splitter (as in the one plugged into the wall) and get a burn or worse...a fire.

 

I've seen it happen in the past where someone has done this and it's gotten too hot to touch!

 

As for legality I'm not sure, common sense should rule on this one to be honest.

[torledo]

It's a bad idea because the cable used in each splitter socket (or whatever you want to call it) is only designed to take the load of however many devices can be plugged into it (ie 2, 4, 6 etc)

 

If you were to chain a second 4-socket splitter into the first one, and had devices plugged into all of the free sockets (so 7 devices) you're likely to overload the max. power rating for the cable in the first splitter (as in the one plugged into the wall) and get a burn or worse...a fire.

 

I've seen it happen in the past where someone has done this and it's gotten too hot to touch!

 

As for legality I'm not sure, common sense should rule on this one to be honest.

 

Can't comment on the legality either

 

As for overloading well that'd be quite difficult if you were in an office environment and everything connected to the leads was PC equipment and peripherals. Things like monitors draw a few hundred milliamps at most...in total you'd have to have an awful lot of PC equipment to overload a 13amp lead/socket. However plug a electric heater into that lot and all bets are off......NOT a good idbea.

 

consider this, if you have no free electrical wall sockets to plug into

getting a qualified spark to add another spur to a circuit for additional single or double gang socket is also a hell of a lot more costly than buying yet another extension lead to daisy chain what you already have.

[Ric_]

There is also the issue that it is a trip hazard which is definately against H&S regs.

[Joedetic]

Well, yes, if all you're running are things like PCs and lower powered devices then you're not going to run into much of a problem. But when it comes to kettles (which are quite often found in offices ), and maybe portable air con units (which some people use in server rooms) the amps start to rack up and in turn the power.

 

If you were to speak to your site manager and ask about getting a quote it couldn't do any harm. It makes it a bit easier if you've already got a ring main in with dado-level trunking.

[torledo]

Well, yes, if all you're running are things like PCs and lower powered devices then you're not going to run into much of a problem. But when it comes to kettles (which are quite often found in offices ), and maybe portable air con units (which some people use in server rooms) the amps start to rack up and in turn the power.

 

If you were to speak to your site manager and ask about getting a quote it couldn't do any harm. It makes it a bit easier if you've already got a ring main in with dado-level trunking.

 

In terms of cost I was referring to a home office, where you're equipment can easily mount up (adsl routers, hw firewalls, lamps etc.) and in a small room you may have only a single double gang socket. Adding additional power points isn't an issue if you know what you're doing or able to follow the correct guidelines. But if you're not comfortable doing it an additional extension lead is cheaper and less hassle. I use to cascade 2 4-way extension leads with portable electric heater and never had any problems - i know it's not anywhere close to extreme but my point is if you're sensible as to how you distribute you're load and don't go nuts then it's not a massive problem cacading up 2 or 3 extension leads.

 

But as i mentioned electric heaters, and yes portable air condiitoing units could easily blow a fuse - so i'd be wary of certain equipment.

[Andrew_C]

It's a bad idea because the cable used in each splitter socket (or whatever you want to call it) is only designed to take the load of however many devices can be plugged into it (ie 2, 4, 6 etc)

That is just not true. If the extension is rated at 13A, the cable is good for 13A. It is true that if you try to run 13A out of each socket you'll be in trouble, a few PCs and monitors will not present a problem. Very long leads should be avoided, but for different reasons.

 

Our H&S advisers deprecate the indiscriminate use of extension leads. If you do a quick mental risk assessment you may well find them to be the most appropriate method to get a couple of extra sockets at a desk.

Trip hazard? Any risk of heaters/kettles being added? All low load devices? Current PAT test? Made to BS (shouldn't be any that aren't, but check)?

 

I have started de-rating the fuses in the few we have around as this guarantees that heaters don't get used in them.

[SteveB_NI]

I have decided to make the job of setting up laptop trolleys in each room a lot easier today.... by running a long extension lead from 1 corner of the room to the back of the room - right by the door. This prevents having to move desks / cause disruption when moving the trolley into and out of classrooms.

 

I plan to cable tie the power lead (and accompanying network cable) at many intervals, and use sticky cable tie fixer pads to secure the cable to existing skirting boards etc.

 

I'm not sure of the legality either, but each socket will have a sign on it saying "For laptop trolley use only" and will be securely attached as much as possible to a wall.

 

Vandalism here is pretty much non-existant here (touch wood) - so bar a few people who "forget" to release the snag on the network cable when removing it, it should be ok!

[m25man]

The Electrical Equipment (Safety) Regulations have not changed since 1994

 

So as far as "Legality" goes in the workplace the only requirement is that all electrical equipment must be "Safe".

 

There really isn't any "LAW" against having 15 trailing sockets/extensions into each other as long as they are all "Safe".

 

H&S is a totally different subject, it cannot encompass or regulate how a consumer/worker uses electrical appliances or installations.

 

If you plug 3 leccy fires and a kettle into a 4 gang trailing lead with a 9 inch nail as a temporary fuse you will obviously be responsible of creating a hazard of immense magnitude and the H&S Inspectorate could close the premises.

The only regulation you have broken however is to make an installation "Unsafe"

 

Who classifies an installation as "Safe", well a suitably qualified person of course!

 

I recently had to have a qualified electrician check my entire house and install a new consumer unit and a switched spur for a shower unit.

 

It took him an entire day to test everything by removing all wall sockets and lightfixings.

His magic leakage tester still detected a short circuit between L&N.

As he was about to leave for the day after telling me my house was "Unsafe" I had to point out to him that his tester was no good whilst the transformer for my Dect Phone was still plugged in!

As soon as I unplugged the transformer my house "Passed".

 

£1200 pounds and 4 days later I had my Part P certificate.

 

Then when I turned on my landing lights the main RCB blew!

 

I called the electrician back after 4 hours of the electricity going on and off, I had to diagnose the fault myself.

 

A previous house owner had used a split circuit to power the US landing lights.

EG. The lights Neutral was taken from the US circuit, the Sw Live from downstairs.

Now when operated the new RCB the "Qualified Electrician" Installed detects the potential difference and pops the RCB.

 

The Electricians answer, cause another £1000 worth of wall chasing and make good damage just to run a 4 core cable from ground floor to loft.

 

Pre 1994 solution would have been to sleeve a spare ground wire with a red sleeve and use this as the switched live.

This he was not prepared to do as it was not "Safe".

 

Accepted solution - Disable the US/DS landing two way switching so now we have to go upstairs in the dark to switch on the landing lights - which interestingly enough is in now in breach of building regulations.

 

I now have 3 different Part P Certificates for the same job, I still can't switch my US landing lights on/off from downstairs.

 

It's all complete load of "B@LL@XS!!".

 

Electrical Safety is Common Sense, Standards can protect you up to the wall outlet, after that it's up to the idiot consumer what and how it is used!

 

For those that want to know more, then here is some more bueracratic eyewash to ponder....

http://www.berr.gov.uk/files/file38628.pdf

http://www.berr.gov.uk/files/file34588.pdf

http://www.berr.gov.uk/files/file39727.pdf

 

What's the Polish for "Certified Electrician" and "Cowboy"

[crc-ict]

It's a bad idea because the cable used in each splitter socket (or whatever you want to call it) is only designed to take the load of however many devices can be plugged into it (ie 2, 4, 6 etc)

 

If you were to chain a second 4-socket splitter into the first one, and had devices plugged into all of the free sockets (so 7 devices) you're likely to overload the max. power rating for the cable in the first splitter (as in the one plugged into the wall) and get a burn or worse...a fire.

 

Sorry, Joe, got to argue here. These things are almost always rated at 13A, which means 13A cable is used from the plug to the bar. And don't worry about the bar itself - I've seen inside enough of these, and the internal conductors are almost always solid metal busbars - a heck of a lot thicker than the cable conductors!

 

To cause a problem, the total load on all the outlets would need to exceed 13A (assuming all adaptors are 13A rated).

 

Granted, it's not the best of ideas, but it's not always a hideously dangerous thing to do. I wouldn't do it at work, but I wonder how many of us could run our technical home empires without using adaptors??

[Joedetic]

@Andrew_C: You're absolutely right that is just not true!! What I'm thinking and what I type appear to be two separate things these days. I meant to put something about subtle hints in design not to plug too many things in to reduce the risk of overloading or something like that. But in the end it's a moot point because this is part of the reason fuses were invented.

[Joedetic]

God what have I started.

 

@crc-ict: I've seen someone powering several guitar amps, one of those big Yamaha electric pianos, some PA kit and some lighting from one 13A socket through the help of daisy chained splitter sockets so that's why I really don't like the idea. It was really getting very hot and I'm not exaggerating!

 

Of course it's down to common sense, but come on....we're talking about the people that call up IT services and ask what to do when their monitor doesn't work and the answer is "turn it on at the wall."

[maniac]

I was told the main reason you shouldn't daisy chain extension cords was because for each plug socket the current passes through in a circuit, there is a certain amount of resistance placed in the circuit. Therefore too many chained together could introduce too much resistance into a circuit, affect the items plugged into it and also generate heat.

 

Also use of the coiled up ones while still coiled is very dangerous if you overload them, as it will melt the cable and the fuse only blows when it's almost too late. Yes I've done it, yes I felt silly, but it goes to show how a momentory lapse of concentration almost led to disaster with extension cords. It was smoking away quite nicely when I discovered it, good job I was around as I'm sure it wasn't far from actually catching light when I caught it!

 

Saying that, several aeas of my house have extension leads plugged into extension leads, and I know of a lot of areas in the school were this is the case, particularly when they use the laptop trollys and run extension leads round the classrooms to keep them going when they've previously not been charged! We keep advising against it, but it still happens no matter what we say.

 

As for the legalities of it, I seriously doubt that it is actually illegal, if it was I'm sure we would be aware of it. It is definitely not adviseable, and it dead against the advise issued in leaflets included with any extension lead.

 

Mike.

[maniac]

God what have I started.

 

@crc-ict: I've seen someone powering several guitar amps, one of those big Yamaha electric pianos, some PA kit and some lighting from one 13A socket through the help of daisy chained splitter sockets so that's why I really don't like the idea. It was really getting very hot and I'm not exaggerating! . .

 

Sounds like the stage at my previous school! I'm not joking either when I say there was only 1 single 13a socket available by the stage. Regulalry it ran a high powered PA system, CD player, digital piano, mixing desk, amps, some lighting bits, smoke machine and other items. They only changed this after one of the governors expressed his concern after attending a performance where the electrics tripped halfway through.

 

Silly thing is all they did was expand this 1 socket into 4, which was still on the same ring main and still regulalry tripped! And because they were all in one place, they still used miles of extension cords!

[john]

Well i've seen what happens when you overload and chain them, and the ocupents in the house are now 6ft under. Its a scary thing the fire service use the lead from the fire as well as actualy footage from the fire as part of Fire Awareness course that I did, its scary, they instantly spotted the 4 gangs in the room they were running the course in and flagged them up as not good as they were chained.

 

Some LEAs may have rules on them, I believe that North Yorks are wanting to ban the use of them except for temporary installs EG laptop and projector for vising speaker in the hall (clearly kick strip on the trailing lead and other H&S needs meeting still) that kind of setup. But not for the computer on a trolley to be used in a classroom for weeks on end, they are frowned upon, I know one place I deal with had them all taken out of the IT area and loads of sockets put all down the wall (why on earth the sparkies didnt put electrical daedo on I've no idea just strips of sockets! But hey ho!) its a lot nicer and safer.

 

One thing I do at home is i use Server Cabinet grade 12 gangs etc as they often are rated at a much higher rating than the cheap DIY store leads, fine they may cost £60 instead of £6 but I just feel they are safer, if the lead is rated for 16amp I know that with my PC kit I won't be over-loading it at all.

 

I am sure there is some form of H&S Rule on chaining them together though, I will email my H&S Adviser who works with me and ask him, he works for places like Olympia doing the show Health and Safety, infact I think he may be H&S lead for Bett this year....

[kearton]

I am sure there is some form of H&S Rule on chaining them together though, I will email my H&S Adviser who works with me and ask him, he works for places like Olympia doing the show Health and Safety, infact I think he may be H&S lead for Bett this year....

Thanks. I look forward to hearing the response.

[john]

Ok I asked my friend who is a Health and Safety consultant, they work for places like The NEC Group, Olympia, Excel (big exhibition halls), various small businesses, some schools and charities, below I have summarised what they have said relating to trailing leads / 4 gangs etc

 

There is no rule at present stating that you can't trail from one to another or use them, but its highly discouraged principally due to the trip hazard they they present as a lot of people don't bother to fasten them down etc.

 

BUT Daisy Chaining / linking together however you wish to term it, is a bit more of an issue as you are introducing the chance of it becoming unstable (they mention that its worth reading up on Ohms Law as that kicks into play).

 

In a very simple level a lot of people tend to think each socket on the 4 carry's the same capacity as the actual entire unit, which is incorrect as it diminishes the more you have, so the more you add the less stable it can become. They certainly would NEVER advise that they are used in Permanent Installations (server cabinets are excluded as you should be using real server grade ones due to the currents they can pull on startup, were talking more DIY store ones here) but for a temporary setup such as a projector, laptop, small speakers etc in the lecture hall etc for a lecture, temp setup etc is ok so long as the trip hazard is dealt with and you do the risk assessment on it as you should be doing anyway.

 

One thing they have said to me is that the Fire Service disapprove of these type of leads in general, especially when daisy chained, and IF there was a fire, they would obviously investigate the cause and, they would be examining this kind of thing.

 

If its used in a more permanent level (temporary is a short term measure such as a couple of weeks at the most really) not a long term such as this year Mr Jones moves into Room 4321 with 3 other office staff and there is one single socket to power everyones computer, copier and fax so we will put in 5 x 4 ways and chain them together, if you had a fire in that room, and its investigated and the cause is pointed to electrical issue, many insurance firms would regard that kind of setup as contributory negligence which is something that should be avoided.

 

They did say some company's / Schools / Businesses H&S policies they have may stipulate other rules on them such as they must not be used, may state that temporary use is 24hrs only and you should check if there is anything specified in your H&S policy, so may be worth checking with your LEAs H&S People just to make sure.

 

So to summarise:

 

• They are legal, but should always be avoided
  
• Never really used in fixed installation,
  
• To be safe never daisy chained due to the units rating being diminished by each item on it (read up on Ohms Law)
  
• Lastly, don't forget the gaffa tape to stick the cable down to remove the trip hazard & risk assess!
  

[laserblazer]

We use them in school because of the combination of laptop/computer, VCR/DVD and audio amp. All low power devices. I have a current meter and check the total load. If the teachers would find a permanent position for their desks then I'd consider having proper mains outlets but I believe the National Curriculum insists that the classroom layout must be changed monthly to prevent the kids getting bored I try and use extension blocks with the right number of outlets but if not, I cover the spare sockets with red gaffer tape.

 

Recently, I found a socket with three neat rectangular holes punched in it. The teacher had plugged a 2KW kettle in to boil some water for a science lesson. This is the main reason for stringent regulations, to cover against stupidity.

[Andrew_C]

Recently, I found a socket with three neat rectangular holes punched in it. The teacher had plugged a 2KW kettle in to boil some water for a science lesson. This is the main reason for stringent regulations, to cover against stupidity.

As I suggest above; change the 13A fuse in the plug for a 5A. Write on the socket in BIG letters "NO HEATERS/KETTLES ETC"

 

Kettle blows fuse, teacher has to 'fes up, and no trashed 4-ways/buildings. 5A is PLENTY for normal classroom use.

[laserblazer]

And who has to drop everything to go and replace the fuse But I take your point.

[apolito]

As far as legality is concerned, daisy-chaining extension cords runs afoul of OSHA's rule 1910.305 (Electrical Wiring Methods). That would be for employers though, not sure about home offices or sole proprietors.

[Andrew_C]

As far as legality is concerned, daisy-chaining extension cords runs afoul of OSHA's rule 1910.305 (Electrical Wiring Methods). That would be for employers though, not sure about home offices or sole proprietors.

Only on the left side of the pond!

[Alis_Klar]

One parents evening was called to a class because a 4 way had "stopped working" . They thought they were being so clever trying to boil 3 kettles off one 4way!!!!!!!! The 13A fuse did it's job and blew (think it blew on the second kettle). Can't remember if the ring main tripped also.