JW420 - Developing Improved Maintenance Tools and Techniques
National Grid Electricity System Operator
National Grid TO Innovation Team
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Innovation Funding Incentive
Health and Safety
The JW420 Bulk Oil Circuit Breaker is likely to see a number of years of further
service beyond its original design life due to its anticipated asset life being
increased from 45 to 55 years by Asset Policy. There are currently 130 JW420
circuit breakers installed on the system.
The JW420 design was originally installed in the 1960s and as such was not
designed with modern health and safety requirements in mind. If National Grid
intends to maximise the life of these assets then ensuring that they can be
maintained in the safest way possible is paramount.
The aim of this project is to provide as safe a working environment as possible
for maintenance activities carried out on JW420 Bulk Oil circuit breakers. The
aim is to ensure the improved maintenance tools and techniques are used
across Maintenance Delivery Electricity (MDE) by further developing solutions and techniques that have been
partially developed and used locally in the past. These include developing the
- 2 light weight access benches
- A light weight rear access working platform connecting the 2 benches to
allow 3 side access to the primary contacts
- A temporary 1kg step arrangement to allow access to the top damper plug
- Temporary flooring for basic maintenance
- Temporary platforms for major maintenance
- Turbulator manual handling device
- Primary contact closing gag.