"During a monthly thermographic and ultrasonic survey at the Sellindge feeder station, a problem was found. At the load balancer, a 110 V DC supply MCB was found to have a terminal with a temperature of 84 °C. This MCB was providing the DC supply to the computer controlling the load balancer.
As a result, once the problem had been found, an outage was taken during engineering hours to further investigate the problem. During the outage, it was found that the terminal crimp was faulty - this was removed, and a new crimp was fitted. The MCB had not suffered any damage because of the early detection of this problem.
Not only did we prevent further damage by detecting the problem early but, more significantly, the load balancer computer did not suffer a loss of supply. If the supply had been lost, the load balancer would have stopped. This in turn would have caused a loss of supply to the CTRL power supply.
This loss of supply would have had the impact of stopping trains whilst the MV supplies were re-configured from an alternative feeder station. This would have also generated significant delay costs in the region of £600 per minute per delayed train. If twenty trains had been delayed by just five minutes, the cost would have been approximately £60,000."
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