GA ABCB Slow Closing Device
National Grid Electricity System Operator
National Grid TO Innovation Team
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Innovation Funding Incentive
Health and Safety
During the maintenance of both the GA6 and GA10 ABCB’s it is necessary to
manually open and close the Circuit Breaker (CB) in a controlled manner.
Historically since GA6 and GA10 ABCB’s were installed on the system in the
1950’s the methods utilised by current workforce to slow open and close the CB
during maintenance never had any bespoke tools provided by the manufacture
to reduce the effect of manual handling. The method employed over the years is
to extend a spanner with an extendable pole (Photo 1). This has proved an
unsatisfactory solution in the past as the practice has resulted in muscular
The Pentir team within NW1 have with limited resources been able to develop
and manufacture a MKI prototype slow closing device. This solution utilises a
torque multiplier in an effort to reduce the manual handling effort required open
and close the CB.
There are currently 43 GA10’s and 19 GA6 ABCB on the system
The project will deliver a safe method of manual handling the spring loaded CB
mechanism which has to be manually opened and closed during maintenance
The key objective is to safe guard the current workforce, This will be delivered in
an effort to reduce the manual handling requirements for Maintenance Delivery Electricity (MDE) Substation staff to
complete maintenance activities in a manner which will not place unnecessary
stresses on their bodies and thus reduce occupational health issues.