Old-style plug sockets

[Stuart Bell]

Hi folks,

I recently moved into a flat that, as well as having 'standard' modern plug sockets, also has some older ones, with holes for three round pins. I have no idea whether these are live, and guess that I could use one of those mains tester plugs in order to check whether they're wired up correctly, but:

a) Are they potentially usable?

b) Are there adapter plugs available to plug in equipment with new-style plugs ... or replacement plugs to connect to the equipment, perhaps?

Any advice would be appreciated -- my knowledge of such things is sketchy to say the least!

Thanks, Stuart.

[Dave Plowman (News)]

If the wiring is all recent, it's common to use this sort of socket for table lamps etc switched from a wall switch off the normal lighting circuit.

You can buy plugs from a wholesaler - even some of the larger sheds. But these sockets - and the wiring - are of a lower rating than the normal 13 amp type - either 2 or 5 amp.

If they are the remains of an old installation which used these for 'power', it should be checked properly - it will be very old, probably 40 years plus.

[Tim]

There was a 15A version too. IIRC it was common practise to run the 5A and

15A on radial circuits and the 2A as arealy mentioned came off the lighting circuits.

2A have been put in as recently as the mid 60's (York University, some of the college residences) and were off the lighting circuit - as proven when too many kettles and hairdryers were plugged into them!

Timbo

[sPoNiX]

There was/is a 15amp version available as well.

sPoNix

[Tim Mitchell]

In article , sPoNiX writes

15 amp is widely used in stage/theatre lighting systems, so is still available and has been updated to have sleeved pins on the plugs, shuttered sockets etc.

[Dave Plowman (News)]

Yes. But I've not seen them in a shed - they tend to be only used for older theatre lighting etc these days. And I'd imagine any in a domestic setting would look very old (and odd) - I don't think many make them in modern styles.

[Andrew Gabriel]

and a 30A one, but you wouldn't have found that in residential properties.

[Owain]

"Stuart Bell" wrote | I recently moved into a flat that, as well as having 'standard' | modern plug sockets, also has some older ones, with holes for | three round pins.

Are these *old* sockets, or new sockets with round pins? In upmarket properties (or those rewired by people with cluefulness) round pin sockets are sometimes used for table lights controlled by wall switches.

Or someone might have (re)used the old wiring for speakers, etc.

| I have no idea whether these are live, and guess that I could use | one of those mains tester plugs in order to check whether they're | wired up correctly, but:

| a) Are they potentially usable?

Potentially yes, but if they are old wiring there is probably good reason for not using them and disconnecting them (ie the wiring is knacked, still on old fuses, etc). Knacked wiring will not necessarily be revealed by a mains tester plug; more extensive inspection/test would be required.

| b) Are there adapter plugs available to plug in equipment with new-style | plugs ... or replacement plugs to connect to the equipment, perhaps?

2A and 5A plugs are available in B&Q. 15A plugs available from other places. Especially if they are 15A plugs you should use a 15A plug-to-extension-socket, so the appliance retains its 13A *fused* plug, so that an appliance that requires a 3A fuse is suitably protected (assuming you have the correct fuses in your 13A plugs to start with) rather than relying on a 15A rewirable fuse in the fusebox.

Owain

[John Southern]

Id like to think they should be dead if they are Live it sounds like ur installation needs a full inspection doing ASAP. The small 2 and 5 Amp BS546 outlets are still used for supllying lamps on lighting circuits but not for anything other in domestic installations.

Jon.

[The Natural Philosopher]

Curiously, its still the standard in S Africa.

[N. Thornton]

And even earlier than 3 pin round pin were the 2 pin 5A round pin plugs. Have an old wooden 2 way adaptor where the metal sleeves come so close to the surface you touch them without sticking a finger in anywhere.

NT

[chris French]

In message , "Dave Plowman (News)" writes

I was looking for a couple of 5 A plugs and sockets in B&Q Warehouse the other day. They had 15A ones there. But then they have all sorts in that one, including various things specialists don't always have

[Frank Erskine]

In article , Tim Mitchell writes

Sleeved pins, shuttered sockets etc are only required for a domestic environment. If you go to a theatrical-type supplier you can buy the real thing in its original deadly form :-)

In fact, 5A round pin plug/socketry is occasionally still specified for new installations in small school/amdram situations. All these are radial circuits with fast-blow (to protect triac-type dimmers) fuses in the dimmer pack, which is (usually!) located in a more convenient place than 30 feet above an audience...

Anybody remember 10A round pin plugs/sockets? I only vaguely remember references to them as somewhere between (obviously!) 5A and 15A sizes. At one time you could buy a card of fuse wire with three bits of wire labelled as 5A for lighting, 10A for heating and 15A for power (whatever "power" was!).

[Bob Eager]

Yes, I remember all those! And having DC mains....

1) Setting fire to a pile of newspapers (and an armchair) when experimentally removing a plug from its socket without switching off the electric fire it was feeding. Nice arc!

2) Having a Tri-Ang train set powered by a rotary converter; then, one day, changing it for this silent red box that apparently did the same job...

[Glen]

Ha ha...we found this out recently. We had rented this fantastic flat done out very swedish in style (not ikea ;) ...which had no centre lights throughout. On the landlords flat inspection b4 we left...he said "You do know that those wall switches work the rounded three pins for turning your lamps on and off?"....oh dear.

1 whole year of coming home in the dark and fumbling about for lamp switches. Doh!!!

Glen

[Tim Mitchell]

In article , Frank Erskine writes

Not true, the regs say you must use shuttered sockets and sleeved plugs on a new theatre install. You won't find any theatrical suppliers selling the old type of plug or socket as the manufacturers have all started producing safer versions.

Even if you could still get "dangerous" versions, it would be unwise to fit them when safer designs are available.

The only disadvantage to the safe versions is that some of the 15A plug designs include a fuse in the plug. You really don't want this in a theatrical situation as everything is protected at the power source and the plugs can be extremely inaccessible.

[N. Thornton]

If they turn out to be several decades old, theres little point in inspecting, they will have no possibility of passing anything.

NT

[Mike]

Most other posts apply but in summary:

If it 5A (or possibly 2A but I suspect not) and is switched by a fixed light switch somewhere nearby then it is probably safe to use for a light.

If it is anything else then it probably isn't safe.

Mike

Stuart Bell wrote:

[Mike Clarke]

I remember some seriously lethal versions of those as a child in the

1950's. The plugs had round covers with a central flex outlet and a moulded thread fixing them to the base. You could easily unscrew the tops from the plugs without unplugging them :-(

I've also come across 2 peculiar type of plugs in the distant past, probably also 1950's or very early 1960's era:

• One type were 13A with round pins. They were about the same size as 5A ones but the earth pin had a groove running along it's length (presumably so the socket could be keyed to prevent a 5A plug being used) and the cartridge fuse was threaded at one end and screwed into the plug to form the live pin. I think they were a proprietary Reyrole design.

• There were some really weird plugs with a central round earth pin and flat power pins to either side of it. They came in 2 (or more ?) different sizes and ratings. The larger ones had a socket for a lower rating built into the cover so you could piggy back a smaller plug off them. ISTR the plugs had cartridge fuses and were designed in such a way that the lower rated ones could also be inserted into higher rated sockets.

[Dave Plowman (News)]

D&S. Lethal things. Sometimes when you unplugged them, the fuse would be left sticking out of the socket - it had unscrewed itself. The natural reaction was to pull it out. Live...

They also had a near useless cord grip.

Often found on council estates.