Power Cubes for Blast Furnace Refurbishment

Overview

When the UK’s leading steel producer was planning the refurbishment of a major blast furnace, the requirement was identified for high concentrations of 400V and 110V power across the worksite, to supply welders, power tools and temporary lighting. Following discussions with the Blakley Projects Team, three types of multi-voltage distribution assembly were developed.

The design brief for all three assemblies was simple:

• Robust, IP65, stainless steel enclosure with lifting / fork lifting facility
• A single 400V 3 wire incoming supply
• 63A switched and interlocked 400V sockets with individual MCB / RCD protection
• Integral 400:110V transformer to provide RLV supplies
• 16A and 32A 110V sockets with individual MCB / RCD protection

Although the design brief was straightforward, the scale of the power requirements was challenging: incoming supplies rated up to 630A; transformers rated up to 60 kVA; up to 12 no. 63A 400V interlocked sockets and 24 no. 110V sockets to be accommodated. The resulting assemblies weighed-in at up to 620kgs each and the different facets of the requirements presented a variety of challenges to the Blakley Design and Manufacturing Teams.

In order to make the units as compact as possible, it was agreed that a “cube” design was the best option, with equipment fitted to all four sides of the enclosures. The use of panel mounted 63A interlocked sockets not only improved the aesthetic appearance of the assemblies but also helped to minimise the footprint and reduce the likelihood of physical damage to the sockets (traditional 63A interlocked sockets are surface mounting and vulnerable to physical damage).

Due to the hostile environment, enclosures were fabricated from stainless steel with a natural finish (unpainted). Lifting eyes were certified and the associated bracketry was based on our type tested lifting arrangement, which has a certified safe working load of 1500kgs.

Smaller assemblies were supplied on stands but it was decided to keep the centre of gravity as low as possible on the larger units and these enclosures feature a heavy duty channel base.