Switchgear Located Front of House

Overview

Most Blakley products are located behind the scenes, whether on a construction site, down a tunnel, in a plant room or supplying power at a major sporting event. However, on a recent London Underground project, there was a requirement to mount switchgear front of house but the appearance needed to blend in with the rest of the installation and the equipment needed to be kept out of the reach of the general public.

The assemblies were to feed lifts as part of the on-going step free access programme, the primary purpose of which is to make the tube system accessible to wheelchair and mobility scooter users. Step free access also helps parents with buggies and tourists with heavy suitcases to use the tube.

Adding lifts to a live, busy Underground Station is no mean feat, as space is always at a premium. The assemblies in question were to house: the main fused switch that supplies a lift; a separate switch to control the lighting and other auxiliary supplies; and an enclosure to house interface terminations for the station BMS system. The main lift isolator incorporated a Castell type K bolt interlock with site specific key. The key controls access to the lift shaft. The switch can only be closed when the key is inserted in the lock and the key can only be released when the switch is on the open position. Thus ensuring isolation when maintenance of the lift is undertaken. In accordance with other LUL products, the switches were housed within steel IP55 enclosures and incorporated metal actuators.

The outer enclosure was made from 2mm stainless steel, grade 316L. The main body was to be recessed and 8 no. internal M8 wall fixing points were provided. The body had a painted finish, Dark Admiralty Grey (BS 4800 shade 18B25). The outer hinged door was manufactured from unfinished brushed stainless steel grade 316L (240 grit type). The door incorporated 4 no. 7mm triangular ¼ turn locks and 1 no. Ronis ¼ turn key lock.