Plug sockets

fuse

Was just in a new house today and noticed there are 2 types of plug sockets everywhere.
1st the standard three pin socket for the rectangular shaped pins.

and then a similar three pin plug except the pin holes were round.

Whats the difference?

buzzard

The plugs with the circular pin holes are for table lamps ONLY. The reason they are different is that they are connected to the fuse board via a MCB and the traditional plug are connected via a RCD.

Sparky

Exactly.

In most installations your 3 pin (5amp) sockets are controlled by your light switches or dimmers too.

HighlyCooL

just while on the subject of 5amp plugs, since they are portable equipment( not fixed or wired in) shouldnt they be on a RCD too. considering the ETCI rule book says that all portable equipment should be on a RCD

ZENER

HighlyCooL wrote: »

just while on the subject of 5amp plugs, since they are portable equipment( not fixed or wired in) shouldnt they be on a RCD too. considering the ETCI rule book says that all portable equipment should be on a RCD

Table lamps are not portable equipment per se. They are not designed to be handled in normal operation like say a drill or a hair dryer.

Where there is mobile or portable equipment which is likely to be hand held in normal use, the device shall disconnect the the supply within the times specified below:

P.T.V. M.D.T.
.
.
.
.
110 0.2
150 0.1
220 0.05
280 0.03

Where:

P.T.V. = Prospective Touch Voltage
M.D.T. = Max Disconnecting Time in seconds

Taken from the ETCI National Rules For Electrical Installations Part 1 General Requirements 1980.

ZEN

HighlyCooL

ah i see. i'll have to have words with one of the lectures in Dit so. he explained it to us that any think the you plug in is portable, and if its hard wired its not. leading me wrong so he is

brightspark

The 5amp sockets must be protected by an Rcd (as well as an MCB of course)


From the National Rules for Electrical Installations Third Edition (new edition due soon I think) ET101:2000

544.4.3

"Socket outlets intended solely for the connection of standard lamps or table lamps need not comply with 554.3 provided the circuit is controlled by a switch.

Note: Rcd protection is required on such circuits."

554.3 basically says indoor sockets are supposed to be the rectangular 3pin type

ZENER

brightspark wrote: »

The 5amp sockets must be protected by an Rcd (as well as an MCB of course)


From the National Rules for Electrical Installations Third Edition (new edition due soon I think) ET101:2000

544.4.3

"Socket outlets intended solely for the connection of standard lamps or table lamps need not comply with 554.3 provided the circuit is controlled by a switch.

Note: Rcd protection is required on such circuits."

554.3 basically says indoor sockets are supposed to be the rectangular 3pin type

Does it refer specifically to 5A round pin sockets ?

ZEN

brightspark

The 5A socket (BS 546) is not specifically mentioned in the Third Edition, though it was in the Second Edition (ET101 1991)

ET 207 2003 (Guide to the National Rules as applicable to Domestic and Similar Installations) states:

Socket-outlets solely for the connection of standard lamps, where the circuit is controlled by a wall switch, may be of any suitable type e.g. IS411, or non-standard indoor type having an earthing terminal. 554.4.3

RCD protection is required for circuit protection in all cases