Triangular white Grelco branded adaptor

13A plug to 2x 13A sockets and one 5A round pin socket.

Three Sockets

Grelco triangular adaptor with 13A and 5A sockets Grelco white triangular shaped 3 way adaptor This triangular shape adaptor has two 13A flat pin sockets and one 5A round pin socket on the front.

Made by Grelco. List No. K/135.

Rear Plug Pins

Back view of a triangular Grelco adaptor showing 13A plug pins and fuse holder The back has a single 13A flat pin plug.

The pins are unsleeved due to the age of this item - sleeved pins were not required when this item was manufactured.

The small red piece is a fuseholder.

5A Fuse

Grelco 5A fuse and red plastic holder Grelco K/135 adaptor with fuse removed The fuse is a BS646 type, 5 amps in this case. The fuse is the original one and is also branded Grelco.

The holder is just a piece of red plastic - it has no electrical connections at all.

Printed Circuit

Printed circuit board C365 inside a Grelco adaptor Grelco triangular adaptor dismantled showing individual components The internals are constructed on a printed circuit board. The 5A terminals and the 13A extension terminals are riveted to the board. The terminals on the back of the plug pins are secured with screws which also secure the pins.

The 5A fuse protects the 5A socket only - the 13A sockets are directly connected. This does mean that in theory, two 13A appliances could be connected, overloading the socket this adaptor is plugged into.


Internal view of socket shutters All three socket outlets have sliding shutters over the line and neutral holes. These are opened by the earth pin being inserted, the earth pin on the plug being longer than the others.

The four brass posts secure the brown plate over the shutters, and the top of each is threaded to accept the screws which secure the two halves of the adaptor together.

The brass posts also make contact with the earth tracks on the printed circuit board.