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Posted By: djk Fragile sockets. - 09/29/03 08:51 AM
Had a weird incident yesterday. A cable reel which was plugged in fell off a countertop giving a sharp jerk to the plug in the wall socket (outlet).

The plug remained in place but the double socket plate split in half and pieces of plastic feel off the front leaving the two plugs fully engaged but with the live innards of the socket exposed.

This was a 15-20 year old MK double switched socket (flush fitted)

Isn't it about time that UK sockets moved over to using fire retardant ABS plastics rather than that brittle white stuff? The plugtops are no longer made of that material. I remember if you dropped an old British plug (even a 1970s/80s version) it would crack and break. I remember seeing plugs with the earth pin loose at the top etc etc.

I know that metal clad versions are a lot tougher but I've seen plenty of instances where a white socket has been hit with a vacuum cleaner or a peice of furnature and cracked and where the householder hasn't bothered to replace it or has just used electric tape to hold it together.

On another point. Why can't BSI specify where the cable should enter socket and switch plates? I've come across plenty of situations where when you remove an old plate that the cables are ridiculously short and will only reach the terminals on one type of plate. E.g. MK's plates all seem to have terminals at the top where as others are in the centre at the back. Surely this should be standardised? If only to make life easier!
Posted By: Trumpy Re: Fragile sockets. - 09/29/03 09:29 AM
djk,
What a question you ask!.
I had a sort of similar thing happen to me in a house over here, where the socket-outlet had been ripped off the wall and exposed live conductors.
Are plugs still made out of hard materials over in the UK and Ireland, we went out of this in the late 70's and all of our plugs are made of really cheap ABS plastics now. [Linked Image]
Posted By: SvenNYC Re: Fragile sockets. - 09/29/03 02:19 PM
The white brittle stuff is either urea or melamine (Melmac). Both are thermoset plastics (meaning that once they're molded, you can't melt them down and reshape).

They are almost similar in composition to the more ubiquitous brown phenolic (Bakelite).

However, brown Bakelite is even MUCH more heat resistant and has the benefit that it won't discolor and crack from exessive heat (such as a high wattage lightbulb). This is the reason why, when I buy "plug clusters" for screwing into a lampholder, I always go for the brown ones.

All three plastics are fire-resistant. I have also have eating plates made of melamine, but do NOT put them in a microwave oven. These types of plastics will not hold up to microwaves. The handle of my 30-watt Taiwanese soldering pencil is made out of Bakelite.

I have an MK plugtop that I bought last year (brand new) from TLC Direct. It does seem like it's made out of Melamine. Heavy, solid, chunky stuff.

I also bought a cheaper thing to compare it with -- the no-name TLC's own version. That one is made out of a softer plastic.

I've noticed that on the flexible plastic ones, the designation is BS-1363-A whilst the designation on the thermoset plastic ones is just BS-1363.

What's up with that?
Posted By: pauluk Re: Fragile sockets. - 09/29/03 10:47 PM
Yes, MK and some other manufacturers still make the urea-based plugs, although the softer ABS types are becoming much more common than they used to be, thanks to molded-on plugs now being standard on new appliances.

Sockets used to take a lot more bashing with vacuum cleaners when it was common for them to be surface-mounted on the baseboard (or "skirting board" as it's called here).

This arrangement was very common in old Victorian houses, as wiring could be carried out by just drilling downward at an angle through the board and running the cables under the floorboards (or in many cases, just running the cable straight down from the socket on the surface of the baseboard).

British manufacturers stopped making most brown fittings years ago. The only place the darker plastic is used now is for the toggle and socket inserts on some fancy brass fittings.

P.S. Should have said rockers instead of toggles. You can't get plastic toggle switches anymore.

[This message has been edited by pauluk (edited 09-29-2003).]
Posted By: GeneSF Re: Fragile sockets. - 09/29/03 11:33 PM
I lived in an apartment complex that was built in 1987 (Vacaville, California).

One day I was lifting a heavy mirror when it slipped and fell right on top of an outlet faceplate ripping it out from the wall and exposing the terminals. The outlet box was made of plastic and had broke. The faceplate and outlet were fine.

An old "Murphey's Law" goes "A $500 stereo will blow to protect a 5 cent fuse."

Oh well, the nice part about paying rent is that the landlord hires the contractor [Linked Image]

Gene--



[This message has been edited by GeneSF (edited 09-29-2003).]
Posted By: Texas_Ranger Re: Fragile sockets. - 09/30/03 11:30 AM
Quote
but I've seen plenty of instances where a white socket has been hit with a vacuum cleaner or a piece of furnature and cracked and where the householder hasn't bothered to replace it or has just used electric tape to hold it together.
So true! I've seen a lot of cracked Schuko outlets, sometimes they weren't fixed at all, in some instances people even tried to glue them back together and they broke again. High-quality receptacles and switches are still made of hard plastic (Berker, Legrand,...), cheaper HD-like stuff is made of a softer plastic. Available in various colors, like white, brown, red, green, blue, yellow,... Price difference: Berker switch at the electrician's: 15 Euro. Kopp switch at Baumax: 3 Euro. Quality difference: probably not much. The Berker switch feels pretty awful when operated. I've never had a Kopp switch fail, whereas an expensive Legrand one did after only a few months of very light use.
Posted By: djk Re: Fragile sockets. - 09/30/03 07:49 PM
Industrial plugs and sockets are all high grade fire retardant plastics that can take quite a lot of abuse.
I don't see why the same can't be used in domestic situations. There is no real reason to continue with these old fashioned hard plastics.

I've seen cracked schuko sockets in use in Holland too. You can still buy hard plastic rewirable schuko plugs here in Ireland although the CEE 7/7 style ones seem to be softer plastic.
Posted By: SvenNYC Re: Fragile sockets. - 09/30/03 08:22 PM
Really? Who from? I'm stuck with getting crimp-on Europlugs.

Soft thermo-plastic....they don't shatter, though.

The ABL-brand Schuko plugs I have here are all a rubbery, flexible material for the husk with a stiff black plastic (almost like nylon) for the dead front. Very good quality things. EXXX-PENNN-SIVE though!!!
Posted By: Texas_Ranger Re: Fragile sockets. - 10/01/03 11:20 AM
Sven, what you get is the tough-grade, splashproof version. Typical rewireable Schuko plugs are made of a rather weak plastic that stands higher falling but is easily smashed by heavier weights. I've seen one at a site, it was patched with paper masking tape! More expensive plugs are made of the same stuff but thicker, so they last longer.
Posted By: djk Re: Fragile sockets. - 10/03/03 01:18 PM
Rewirable schuko plugs here have a fairly normal plastic outer layer and a black harder middle bit.

Looks a bit tougher than BS1363 equivilants
Posted By: SvenNYC Re: Fragile sockets. - 10/03/03 02:16 PM
Figures... I always wind up buying the heavy-duty industrial stuff.... [Linked Image]

Can you imagine hooking one of these up to a little table lamp? Talk about overkill.
Posted By: Texas_Ranger Re: Fragile sockets. - 10/03/03 07:45 PM
Quote
I always wind up buying the heavy-duty industrial stuff...
Well, industrial is not exactly the right term. Industrial appliances either use blue CEE plugs or really heavy Schuko plugs made out of real black rubber.
The plug you once posted a pic of, the one with the soft white plastic shell is more like a plug for garden tools, your lawnmower cord and light construction stuff. For example I've seen wuite a lot of small sanders refitted with those plugs. I've got only one of them, I got it attched to a string of christmas lights. Boy, that looked weird! Especially since the genius wired it like this: Attach strip connector to light string. Hook up 2 30cm pieces of purple 1,5mm2 solid wire intended for use in conduit to strip connector and connect plug to the plug. Don't even bother to use the plug's strain relief or tape the connection. I refitted the old ungrounded plug that still lay in the box. Otherwise I mostly got used stuff from times long gone, really solid stuff, and new construction grade stuff for lawnmower cord and construction stuff (I do lots of DIY, for floor sanders, rotary hammer and similar appliances you can use a good construction grade heavy rubber extension cord).
Posted By: pauluk Re: Fragile sockets. - 10/03/03 11:24 PM
Quote
Can you imagine hooking one of these up to a little table lamp? Talk about overkill.
Have you seen a table lamp with thin zip-cord wired to a 15A BS546 plug? Now that really looks like overkill..... [Linked Image]
Posted By: djk Re: Fragile sockets. - 10/03/03 11:44 PM
For a size comparision BS546 is almost as bulky as a blue CEEform plug and the line and neutral pins are the size of the CEEform ground pin. The ground pin is bigger again.

I've seen one attached to a handheld blender. It was 50% the size of the applience!!!

---

On another point, it's more and more common to only have CEEform (blue) outlets in commercial kitchens here so it's not too unusual to see a little braun hand blender or other kitchen gagets with a huge blue industrial plug on the end!

---

The Regs in industrial/commercial situations are getting tougher and tougher.
E.g. BS546 15A was the norm in theaters here for many years. However, because of HSA regulations only CEEform is acceptable now.
Many dimmer units etc come with BS546 sockets so it's now standard practice to wire them like this:

BS546 permanently connected to a short cable leading to a trailing socket and CEEform (blue) from there. This means that operatives normally never have to deal with anything other than CEEform.
All theater lighting rigs are now blue ceeform too, no BS546 stuff allowed.

[This message has been edited by djk (edited 10-03-2003).]
Posted By: pauluk Re: Fragile sockets. - 10/04/03 12:25 AM
Did the Irish authorities give a reason for banning BS546 in theatre lighting?

BS546 certainly remained the norm for such use here, and as far as I'm aware it's still widely employed in theatres.
Posted By: Hutch Re: Fragile sockets. - 10/04/03 01:56 AM
Quote
Have you seen a table lamp with thin zip-cord wired to a 15A BS546 plug? Now that really looks like overkill.....

You should visit South Africa sometime where everything hangs on one of these! They look perfectly normal after a while. [Linked Image]

A lot of my 240V gear here in the US is still on these because I have not come across any 240V power strips, besides which all these plugs are paid for!

Here's the front of my bench: 240V left, 120V right:

[Linked Image from frontiernet.net]

[This message has been edited by Hutch (edited 10-03-2003).]

[This message has been edited by Hutch (edited 11-01-2003).]
Posted By: djk Re: Fragile sockets. - 10/04/03 05:07 PM
There is a simple reason:
Only 2 types of sockets / plugs are recognised by Irish Standards (IS)

IS/EN60309 Ceeform
IS 401 which is BS1363 (Restricted to Domestic, office and similar uses)

BS546 and CEE 7/IV (Schuko) are only mentioned in legislation here to make sure that any plugs/sockets sold as replacements for legacy use conform to the latest BS or DIN or CEE specs as appropriate.

---

The HSA (Health and Safety Athority) would deem BS546 unusuable as it doesn't recognise the standard and it would not be able to get certification on how it would perform mechanically if for example it was hit by a peice of lighting rigging.. How it would cope with damp etc.. As a connector it's designed primariy for domestic use.


Under HSA rules, Health and Safety at Work Act etc Irish standards and ETCI wiring rules must be complied with otherwise in an accident the employer is fully liable etc.. and the HSA could take legal action for breeches too.

It would be illegal to use BS1363 or Schuko too.

----

IS/EN60309 is starting to appear all over the place.

Outdoor christmas lights
Garden / patio sockets

Trailing extensions for commercial cleaning equipment.

IS401 fused plug feeding 16 Amp IS/EN60309 trailing sockets / reels etc for polishers, vacuums etc etc.


[This message has been edited by djk (edited 10-04-2003).]
Posted By: pauluk Re: Fragile sockets. - 10/07/03 01:50 PM
It sounds as though the Irish HSA is getting every bit as persnickety as the British HSE (Health & Safety Executive).

As bulky as BS546 15A connectors are, the 16A CEEform types are huge for such use. For individual lights up to 1kW or so the BS546 system at least offers the much smaller 5A versions, and on all the theatre lighting I've been involved with we used a mixture of 5 and 15A connectors.
Posted By: SvenNYC Re: Fragile sockets. - 10/07/03 02:38 PM
Paul, probably the Irish HSA doesn't want people using BS546 plugs in theatres because some of them are quite fragile.

Just like the domestic (cheap) BS-1363 plugs, some BS-546 are made out of the brittle thermoset plastics.

Of course, I've seen heavy duty rubber BS-1363 plugs from MK and others...but they're expensive -- like two or three quid versus a few pence for a no-name "domestic" plug to a pound and change for an MK type.
Posted By: djk Re: Fragile sockets. - 10/08/03 07:59 AM
The Ceeform stuff is a lot cheaper and a whole lot more flexible in terms of what's available.

Also, the normal IP 44 version isn't all that bulky in compairson to BS546 (15A). The higher IP versions that are often seen outdoors where they're exposed to rain are a lot bulkier looking.

Sven:

I've heard stories of people getting shocked by BS546 plugs in these situations. E.g. a guy puts his hand up into rigging to remove a plug that's out of view which has been cracked by being hit/dropped.

A lot of theater equipment has somehow escaped the wrath of the HSA until relatively recently. There were some truely disgraceful installations out there. They're not only concerned about electrical safety mechanical issues come into it too. Lights / rigging have to be safe.

I have never seen the 5A version in use in theatre over here btw.
Posted By: pauluk Re: Fragile sockets. - 10/08/03 09:42 PM
Point taken about the costs of heavy-duty BS546 connectors these days. As for a broken plug becoming a shock hazard, I really think that's down to due care and maintenance. Any equipment can be a shock hazard if it's allowed to be used in such a condition.

I've seen some CEEform connectors where heavy use and repeated withdrawals has weakened the hold of the fixing screws into the cap, and eventually an attempted withdrawal just results in the cover pulling away leaving exposed terminals (although I have to admit that the latter tend to be shrouded to a greater degree).

Back in the 1980s I was involved with sound and lights for a local amateur dramatics group, and the control booth high at the back of the village hall was full of old equipment, including several very large rheostat dimmers that would probably fail a large number of the safety rules of today.

Last I heard, which was just as I was about to leave, the local sparky was telling the committee that the "solution" would be a row of about a dozen BS1363 outlets over the rigging, each wired individually to its own domestic-style dimmer in the booth. He obviously had absolutely no idea of theatre lighting requirements. [Linked Image]
Posted By: Hutch Re: Fragile sockets. - 10/09/03 02:12 PM
The most serious electic shock that I have suffered has been at the hands of amateur theater lighting with BS546 plugs in a setup very similar to that descibed above by Paul. In this case the plug to the dimmer bank had some how become back fed and an exposed pin which I grabed was live. A shrouded assembly would have helped but mis-wiring somewhere was the main culprit.

I was lucky in this event that the shock threw me against the lighting deck guard rail rather than through the adjacent ladder gap and 10ft down on to the stage!
Posted By: pauluk Re: Fragile sockets. - 10/09/03 06:24 PM
One common arrangement in the past was to have a bank of sockets inserted in series with the live feeds to the lights, and dimmer connections provided with matching plugs to allow linking of a rheostat into the required circuit. Switches were then fitted to short out sockets which didn't require an individual dimmer, and often changeover switches to provide Direct and Master dimmer feeds.

I think some people got a little confused over this use of connections and could end up wiring something so that a plug was left live.

Not nice to grab hold of, as you say. [Linked Image]


[This message has been edited by pauluk (edited 10-09-2003).]
Posted By: djk Re: Fragile sockets. - 10/09/03 07:20 PM
BS1363's fusing is a bit problematic for high wattage dimmed lamps too. Not to mention the hastle of climbing or lowering rigging to change a plug fuse!

Generally BS546:1950 ( & ammendements) is just considered an opsolete standard here. Strangely enough though, so's CEE 7/4 (Schuko). Stranger still, BS546 was never an offically recognised standard at all in Ireland it just appeared.

It's difficult to get your hands on spares, the plugs available tend to be hard thermoplastics rather than the rubber variety etc.


[This message has been edited by djk (edited 10-09-2003).]
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