OT(ish) ... fire occurences ?

[Jethro_uk]

Just vaguely wondered if the trend towards lower power lighting has led to a reduction in fires caused by overloaded wiring ?

[Andy Burns]

How many lighting circuits were overloaded to start with? more than 14 x 100W incandescents on a 6A breaker ...

[Caecilius]

I suspect not.

In the good old days, we had inefficient tungsten lamps that were expected to get hot, and therefore in bulb-holders and shades that were designed to cope with the heat. The cable was standard T&E with

6A MCB, and never got anywhere near that except when the bulbs failed and tripped the breaker due to the arc causing a momentary surge.

Now, we have constant current LED drivers, which are packaged into matchbox-sized potted units with poor heat conduction. I recently upgraded my old 3W TLC ceiling downlighters with the new 6W COB units with new constant current drivers, and was surpised to find that all the old drivers were discoloured and crispy. I'm not sure it represented a fire hazard, but it didn't look like the ideal crispy critter to situate in the void between ceiling and floor.

[alan_m]

Don't you have one of those light socket adapters when you plug in an iron and a 3 bar electric fire?

[Roger Hayter]

My mum had an iron with a bayonet plug, and a bayonet Y adapter which could be plugged into a table lamp with the iron in one branch and the bulb in the other. I think we also had a one bar electric fire with a bayonet plug, but I am not sure on this. It might have been the old 5A three pin plug.

[Dave Plowman (News)]

Far more likely to have cause accidents tripping over things in that dim light.

[tabbypurr]

Even 1mm cable is rated at 8-16A & capable of more. Genuine overload would be hard to achieve.

Poor wiring connections now are less likely to burn, with much less heat generated. But socket wiring is much more of a risk in this respect anyway.

NT

[Brian Gaff]

And more caused by overheated power supplies probably.

Brian

[Jeff Layman]

Indeed. I can remember my mother ironing using the ceiling light socket. If it was during the day, the bulb was removed and the iron plugged in. If the daylight was poor, a Y adapter was used, leaving the bulb on one arm. I am not sure, but I believe the irons at those times were not very big, and probably had a 1kW or less element. As far as I know the 5A fuse never blew when the iron was used (and we did use the proper wire!).

As an aside, a few years ago, while clearing my father-in-law's shed I came across an "asymmetrical" adapter. Instead of connectors at 120 degrees, one was straight through (ie 180 deg), and the other at .IIRC,

120 deg. Anyone else ever seen one of these?

[Max Demian]

That was a common design for two way lampholder adapters. The straight through connector was switched, so you could iron in daylight without the light on. Your mum could have done with one of those. There were also 5A two pin to bayonet adapters, so you could plug something into the lamp socket that would otherwise be plugged into a power socket, with or without a multiway adapter for 15A &c.

I moved into a newly built house in 1957, so most of my childhood enjoyed 13A square pin sockets. When I left home in the late 60s a lot of the bedsitters still had the old round pin sockets. You could get multi purpose plugs that would fit the modern 13A sockets and also 2 and

3 pin 5A and 15A sockets. The pins screwed in and out and you had to squeeze the plug to fit the 2 pin sockets as the spacing was different than the 3 pin versions.

[Bob Eager]

Yes, they are the ones I was used to. I don't remember any 'Y' adapters!

(my father worked for the electricity board, so we got all the new- fangled stuff. That included 13A sockets even though we had radial mains circuits)

[Rob Morley]

That's the only sort I've seen - the straight-through was for the bulb, so you could leave the adaptor fitted and it would hang properly, and the sideways one was for your wireless set or whatever.

[harry]

Most electrical fires these days are caused by rodents nibbling the wiring. You need to make every effort to keep yourself rodent free Rats, mice and squirrels.

When I rewired my present house, several wires were nibbled I discovered.

[Tricky Dicky]

A bed sit I moved into about 1972 had some weird sockets made by Wylex. The y took a round plug that had a circular central earth prong with two rectan gular shaped prongs either side of the central prong. They came in two size s a 15A and 5A if I recall. The 15A ones had a plug through which allowed y ou to plug in a 5A one. Used to have a devil of a time getting ones to fit in the end I made up short extension leads using standard 13A multi sockets .

Richard

[Terry Casey]

Ah yes - the Fitall plug!

Highly popular with pop groups due to the various sockets found at different venues - even BBC studios which were always

5A 3pin in the 60s!

There was a problem with the design though, which only showed up when used with metal clad 13A sockets. The thin paxolin plate that swivelled to open up holes in front of the 2, 5 &

15A pins as approriate, also allowed the 5A live pin to partly leave the plug when using the plug in the 13A position.

The force necessary to open up the shutters meant that when the plug stopped moving, the 5A pin shot forward and came into contact with the metal housing! This, of course, was upstream of the 13A fuse in the plug, so the comsumer unit fuse/breaker was the limiting factor.

A modern hall near me had a very generous supply of 13A sockets all round its stage area - all metalclad, of course!

Every time I went there, the number of sockets with the incriminating pock mark next to the live pin hole had increased by two or three!

The Fitall plug was eventually modified to stop this happening but the best solution to the original type was to place a piece of thin card - usually from a cigarette packet - over the socket, then use the plug to punch holes for the pins through the card.

[Terry Casey]

I started working for a local Radio & TV dealer in 1960 and our benches had boards with every conceivable mains socket fitted - including the dangerous Dorman Smith version of the

13A socket, mainly used by large council estates such as the LCC overflow estates nearby and those Wylex sockets.

In the nine years I worked there, the Wylex sockets were the only ones that never got used!

[Dave Plowman (News)]

Not so. The standard in TV centre for technical supplies was a round pin

13 amp system known as D&S. The live pin being a fuse, so replaceable without a screwdriver. Later changed to Walsall guage - 13 amp with flat pins, but each pin rotated 90 degrees.

Some older studios - never refurbished - may well have still had 5 amp, though.

[Mike Clarke]

Yes, still got a couple in my box of antiques^H^H^H^H^H^H^H^H junk. They both have a switch for the branch connection, one with a string switch and the other with a plastic bar, red one end and white the other, that pushes through the casing.

The last time I used one would have been to power my Anglepoise desk lamp in a student bed-sit in 1966. Prior to that one was regularly used in an improvised darkroom in the broom cupboard under the stairs at home, the switched straight through connection fed the white light and a further adaptor in the side branch with a BC socket and a couple of 5A 2 pin sockets fed the enlarger and safelight.

I think one of the main dangers of these adaptors was the risk of damage to the insulation of the pendant flex rather than over-current. The flex for ceiling lights in those days was usually a twisted flex of two wires each with cotton covered rubber insulation. Over time the insulation would harden and crumble with heat from the light bulb and I remember replacing several flexes where the only insulation between the conductors just above the lampholder was fresh air. The extra disturbance from frequently plugging things into the branch connection and switching the light would accelerate the crumbling away of any brittle insulation and close the air gap.

[dennis]

My parents house was fitted with those plug and sockets.

[Terry Casey]

Ah, never visited a TV studio, only radio: Playhouse Theatre, Paris Theatre, Maida Vale, BH, etc.

Never thought to check if the Control Rooms were also 5A but most would been hidden from view, anyway.

D&S = Dorman Smith that I referred to earlier. Had a habit of the fuse getting loose with repeated insertions - probably mainly in domestic applications - until, one day, the plug was removed from the socket and the fuse remained behind leaving the screwed extension protruding!

You did say 'technical supplies' - you wouldn't expect a performer who turned up with their own electronic equipment to be equipped with those connectors, would you?

Well most of those I listed above would certainly fall into that category[1] although by BH I was refering to Broadcast House Extension which was much newer.

[1] The first studio I visited was the Playhouse Theatre. I spent some time during rehearsals attempting to repair a broken guitar lead but my soldering iron didn't seem to be getting hot enough to melt the solder. A meter placed across the mains registered 197 volts!

The place was closed down for 18 months shortly after that for refurbishment ...