Bender UK
Approval of Tier 2 and Tier 1 Rail System Insulation Monitoring Has Paved the Way for Widespread Upgrades across the UK
This article first appeared in the Railway-News magazine, Issue 2 2023.
Full approval of rail safety technology from Bender has enabled more widespread investment in intelligent insulation monitoring of signal power systems in the UK.
The new generation multi-tier RS4 Rail Signalling Power Monitoring delivers increased sensitivity for first fault location and remote condition monitoring of core-toearth failures, which accounts for most faults on signal power systems. RS4 helps to reduce maintenance, infrastructure and service failures and improve staff safety by minimising trackside intervention (‘boots on ballast’).
Bender RS4 technology was developed in collaboration with Network Rail in response to the standard NR/ L2/SIGELP/27725 which defines requirements for insulation monitoring and fault location for use on IT electrical systems where the nominal system voltage does not exceed 1000V AC or 1500V DC. Network Rail regulation NR/L3/SIGELP/50001 requires an increase in intervention windows. Faults identified at critical stages (20kΩ or lower) require immediate intervention within 24 hours. Advanced monitoring and insulation fault location at up to 100kΩ increases intervention time, enabling fault identification within a prescribed six-week window. More importantly, it also offers the option of dealing with the fault over a longer timescale through planned and predictive maintenance.
Bender systems were the principal method of tracking and locating faults on the UK rail signalling power network for two decades. However, less critical emerging faults at lower intervention/ insulation limits have been difficult to track and pinpoint.
Network Rail demands maximum visibility to assess the health and condition of its power systems to support signals, points and communications infrastructure. Manual cable testing on a five-year cycle continues to be a requirement, but RS4 is a key step forward in enabling Network Rail to move from periodic testing to a real-time condition-based approach through continuous monitoring.
