Guys,
I've just been wading through a report by the New Zealand Fire Service and it doesn't make for good reading.
Especially as far as the Common 3 or 4 way multi-box is concerned.
Figures collated from Incident Fire Reports, show that multi-boxes had a dis-proportionately large showing in the causes of House Fires.
What tends to worry me, is I've seen these things at fires and although they do have an in-built Overload device, I've still yet to find a fire damaged one that the Overload has actually operated on, none of them have actually tripped to prevent the box from overheating, melting and consequentially starting a fire.
What scares me even more, is the fact that I've seen in DIY store leaflets here, versions of this sort of thing, with 4,6,8,10 and 12 sockets on them, all fed from a 10A Socket-outlet.
Sure, I realise that a fair bit of common-sense is required on the part of the user, but having said that, how many Home-owners do you think, would be bothered to even check what sort of wattage they are putting through one of these devices?.
(Especially during the Winter)
However, in the majority of cases (here anyway), these devices are hidden behind wooden Entertainment Centres, under plastic TV sets and in some cases, under beds.
I'd personally like to see the things banned, after all, they are really only a stop-gap measure where there aren't enough Sockets installed in a given room.
What do you guys think about these devices and thier use?.

I tend to agree Trumpy. Some of these things do seem to be inviting disaster.

I would like to see more of them fitted with MCB protection, instead of fuses.

The huge ones, used ostensibly for IT/entertainment equipment, are a disaster waiting to happen as they become more and more available in the shops.

Banning them? This would be ideal - but I don't know how easily one could justify it... I have a six-way under my PC, and each way is in use. It is plugged into a twin 13A socket - the desk-lamp is in the other half. To fit seven sockets ( or four doubles anyway ) would be a bit of an eyesore if I ever decided to move the PC station!

I guess we have to fall back on good ol' common sense - and put out the inevitable fires... Don't really know what other solution there is to be honest...

Yeah John,
You're right!.
There is not a lot you can do about these things.
The multi-boxes here do have an MCB in them, but what thier Time/Current characteristic is like I'm not sure.
BTW, here's a picture in case anyone is wondering what I'm on about:



The Red dot next to the cable entry is the Overload MCB.

{Message edited to add last comment}

[This message has been edited by Trumpy (edited 01-04-2005).]

They should be reasonably OK if protected by a fuse / MCB. The ones that worry me in UK/Ireland are the unfused double-adaptors. It's quite easy to overload a 13A socket with one of these by simply plugging in 2 heavy appliences and I've seen them used in kitchens with kettles, toasters etc etc..

I'm not sure about banning them as an overall device. The fuse or C/B should provide adequate overload protection. If it doesn't, then shouldn't we be addressing the quality of the unit in question rather than the concept as a whole?

The simple sollution would be to require that all multi-socket devices carry over current protection at a rating appropriate to the socket outlet it's going to be plugged into.

i.e. 13A in the UK/Ireland and Denmark
16A in CEE 7/7 countries.
10A in Australia / NZ

I have never seen a powerstrip cause a problem here. The only thing I've seen melt and catch fire is an extension reel which was fully loaded and not uncoiled. They should be designed to withstand a bit more heat or at the very least have a temprature trip out on the reel housing.

I'm with Dave. Mike, you'll probably be shocked to hear that we have these things with 16A sockets/plugs and 1.0 mm2 cord and no fuse. I've never seen a fused version. (Reels are fused, though.) You'd think they would at least require the cord to be adequately (sp?) sized

Paul has a good point with respect to quality. It's not really an MCB in these things, only a simple thermal element.

You guys are right though!.
This kind of had me thinking about the sort of protection used in these devices.
So off to work I trundled, with a multibox and hooked it up to one of our Variable Dummy Loads in the Transformer workshop.
Using a steady voltage of 230VAC I wound the Load down to 11 ohms and waited for the OC device to trip, after 240 seconds the MCB on the test board tripped.(I=21A)
I hooked the unit up to a 32A MCB and repeated the test, I turned it off after 10 minutes, as the Multi-box was starting to smell funny, and when I picked it up, it was more than warm to the touch, but still the OC device never tripped.
Paul,
Yes, very true, after having done that to the box I thought I'd open it up and see what makes one of these things tick and inside there is a series of Phase, Neutral and Earth busbars inside for each socket, although I use the word busbar loosely as the bars were about three times the thickness of tin-foil and bent rather easily.
I picked up the little over-load and dropped it again as it was really hot!.
The build quality of these boxes we get here these days is rediculous, even the cords don't even look like they would handle a full 10A, if they had to.
Another concern is though, the majority of the houses where these devices are used, don't have MCB protection, instead having the original Porcelain fusing.
I suppose at the end of the day, it all comes down to who can make the product the cheapest, even if quality is lower than it should be.

It's one thing that the BS1362 fuses used in the UK and Ireland have going for them! They're cheap, small, easily available should they blow and made to a reasonable specification. I would be very wary of resettable MCB style over current protection in some of those cheap power strips (multiboxes)

The quality of powerstrips is certainly very variable. I've seen BS1363 types very similar to what Mike describes -- Thin "busbars" with the contacts for each outlet integral. Many of the older 1960s strips were far superior in construction, with a line of individual panel-mount BS1363 sockets fitted into a solid metal enclosure.

Dave,
After doing that little experiment, I'm convinced that our Electrical Regs are barking up the wrong tree here.
I busted open one of them Over-current devices on an imported multi-box that Brian XXXXX a local Inspector and I bought from a local Big Box store here.
Brian managed to get 56A out of the box before it exploded.
{Get 2 Radio Hams in a place like the PoCo workshops, there's bound to be something blown up!}
But all I found was a 240C Micro-temp, hardly good enough for a plastic bodied (appliance?), the spring and button was just for show.
Paul,
That could be said of a lot of Electrical products these days, cheap stuff makes more money.
But I don't think we'll be going back to Bakelite switch plates or Lead-Sheathed cables.

Just on the subject of Multi-boxes,
here's a strange little device I saw while sourcing some parts from an NZ Electrical Parts supplier:



One question though,
What type of an outlet, is the one on the bottom right hand corner?.

Looks like Italian. And the one above it is Swiss.

Thanks for that Paul.
I've never seen one of them Italian outlets before.
I've seen all the others.
I'm assuming that they use 220-240VAC in Italy?.

Yep, 220-230V although like some other European countries there might still be patches of older 127/220 systems left (possibly with only phase-to-ophase loads now).

Don't forget C-H's site:
http://www.global-electron.com/details.asp?ID=IT
http://www.global-electron.com/plugs/L.htm

That is a box used for testing electrical devices made for export. Interpower is an american company that specializes in supplying cordsets and other assorted power products (cords, plugs, sockets, etc) to american companies that are exporing electrical products to europe, africa, asia, and elsewhere.

Trumpy that's a 10Amp Italian socket.

There is also a 16Amp version with fatter pins spaced further apart.

However, recessed schuko sockets with an extra ground receptical in the centre have started to appear. These happily accept the common 3 pin italian 10amp plug and normal Schuko 16A plugs.

Many appliences sold in italy ship with grounded schuko plugs or 16amp ungrounded contour plugs neither of which will fit the old-style italian 16amp socket.

It's quite likely that the italian system will disappear in the not too distant future.

Often the Italian 16Amp socket outlets won't accept the 10A plugs.. so the Italian version of Schuko makes more sense in terms of compatability around the house.

i.e. heavy appliences use schuko and small appliances use europlug / italian grounded plugs but you can still plug a small applience into any of the sockets.




Italian Schuko socket (hard to see the earth receptical, but that is a receptical not a screw!)


Italian Plug 10Amp


16 or 10A italian socket accepts both pin diameters.


Italian 16A plug

Oh and just to confuse people : there's a 10A un-grounded plug which looks identical to the usual 2.5A europlug but has 4mm pins! This is commonly found on items like Italian hairdryers, travel irons etc and will usually mate perfectly with a schuko or french socket. But jamming it into an older European 2 pin non grounded usually isn't possible as the pins are too fat.



[This message has been edited by djk (edited 02-28-2005).]

Dave,
Thanks a lot for the pictures!.
I wondered what the plug looked like.
Am I right in saying that the plug is an un-polarised type?.
Just a little question for everyone, most manufacturers these days use the moulded-plug type cord-sets for thier appliances.
Is it still possible to buy the re-wireable types to replace the moudled type, where you are, should the wires break in the flex, where it leaves/enters the plug?.

Trumpy,

In the UK and Ireland absolutely no problem at all. Every corner shop seems to sell 13Amp BS1363 rewirable plugs.
Many hardware stores also still stock re-wireable schuko (in Ireland) and BS546 plugs. (in Ireland and the UK)

In France, it was also possible to buy plugs both 2 pin and grounded in any supermarket.

I'm not sure about the rest of Europe

Good on you for bringing up the multi-box issue Trumpy. I have done some current tests on these multi-boxes too, with the same scary results as yours. Problem is: that multi-boxes aren't a "Declared Article" under our commerce law. Even though they contain an overcurrent device. Which means that neither the manufacturer or the importer has the ability to guarantee the calibration of the overcurrent device. Circuit breakers, fuses and other current-protective devices are all "Declared Articles" whch are required to be stamped with an approval number which effectively guarantees its callibration. Its great to hear from people like you Trumpy with experience of the end result of crap products like the
4 dollar multi-box.

Kiwi,
Good points about the Declared Articles.
But have you seen with the latest round of drivel from the ESS that the Declared Articles list is now null and void.
Which more or less gives importers a free reign to import whatever rubbish they like.
As an Electrician I won't be installing any of it.
That may be why we are going over to Licencing, instead of having our own Registration, maybe they don't want us to be in a situation where we can argue.
Free Trade eh?

Mike... it is great (well not really ) to hear that you actually substantiated a basic premise about these things... they are unpredictable at best.

Is that report you referenced in your original post available on-line? Although I'm in the US, I've been very interested in the "multi-box" issue. They really "burn" me up!

I suppose you've seen the similar thread that's been running in the "violation photo" forum. https://www.electrical-contractor.net/ubb/Forum4/HTML/000183.html

One of the points that I made in that thread about these devices in the US is that although not inherently unsafe... they are just too prone to abuse. It seems that there is universal disdain for these around the world.

But... C-H wrote:
That may change my mind about some of these devices being inherently unsafe.

Mike... You didn't happen to take of photo of the device that "exploded"...did you? Now that would make for a great training illustration when I'm doing general electrical safety training for unqualified people.

Glenn,
No I didn't happen to get a picture of the "broken" one, in the end.
But, I can just as easily do it again!.

Mike...
No... that's OK, let's skip another trial run of this "experiment"!

We want to keep you in one piece.

A point to ponder,how safe is a US $2.99 powerstrip?


P.S. I do not like them,but have 2 of them behind behind the TV,one is an older model using Hubbell components,and the other model is a Wiremold product,certainly a case of saying 1 thing and doing another on my part.

No, as far as I've seen most Italian wall sockets take both 10 and 16A plugs. I only saw a 16A only socket once and that was a rather industrial looking IP44 surface mount one.

It is indeed true Schuko is really catching on in Italy.

At home I have a 1200W hair dryer with a Euro plug stamped 250V 2.5A...

Most ungrounded sockets were designed for 4mm pins and the ones I've seen almost always take 4.8mm pins too. It's quite easy to jam a Schuko or contour plug into one of these (and not even a problem with a contour plug, always do that with the vac in our living room.
Germany had 10A ungrounded plugs with full metal 4.8mm pins, as opposed to the older 6A ones with slitted 4mm pins. Never saw them in Austria though, and our ungrounded trailing sockets never take more than 4mm pins.

Rewireable plugs are readily available, though the quality has dropped noticeable.
One of our first jobs at my new school was to build a 5m extension cord. looking back I can say it was the most professionally built extension cord with the nastiest and cheapest components I've ever done.

Still love the ancient bakelite Schuko plugs with porcelaine guts... if you don't smash them they're indestructible.