RETROFIT: Innovative technology at work

Launch of new circuit breaker

Hawker Siddeley Switchgear (HSS) is in the process of commissioning the first 31 SWR retrofit circuit breakers with a UK distribution network operator.

The SWR is a brand new product, developed at the new HSS Technology Centre at Loughborough. The breaker is designed to be a direct roll-out/roll-in replacement for old South Wales Switchgear vertical isolation 11kV oil circuit breakers. These oil circuit breakers were sold in large numbers in the UK and worldwide during the boom years of electricity network expansion between 1950 and 1975 and are now due for replacement.

“A vertical isolation circuit breaker is a truck-mounted three-phase breaker on wheels,” explained Steve Lane, Engineering Director. “It’s rolled into a fixed housing, into which it is vertically racked into position; thereby plugging into the circuit it is intended to protect (much like plugging in a fuse).”

The SWR12 is a magnetic actuator-driven vacuum circuit breaker and uses HSS patented core technology for which the company was granted the UK’s highest award for innovation by the Royal Academy of Engineering. This technology, employed in all HSS current products, significantly reduces the complexity and improves the reliability to such an extent that they are considered almost maintenance free.

The availability of the SWR12 gives customers the option of extending the life of the fixed housings by rolling out the oil breakers and rolling new vacuum breakers quickly and simply with minimum disruption to the network. The need for new civil work, cabling and so on will no longer be necessary to replace the complete switchboard.

Other customer benefits include a reduction in maintenance requirements, the removal of oil-based products from substations and safety interlocking and certification to the latest international standards. A second variant of the SWR12 is due for production in April 2014.