A major HV fault had taken out all non-maintained supplies across this hospital site, resulting in emergency generators having to deliver a maximum of 60% of the supply needed. Before the on-site maintenance team could attempt to repair the faulty cables, all LV supplies needed to be isolated to ensure no back feeds would occur. It was only after isolation of the obsolete LV Air Circuit breakers that a problem came to light - the breaker’s that had been opened would not re-close. Additional support and expert assistance was urgently required.
As an Embedded Contractor for the NHS Trust, we were able to respond immediately to the urgent request. It was clear from investigations that the breakers had not seen maintenance for some time, which would indicate that a systematic clean/check of all switches and contacts should be the first element of any remedial maintenance. After several hours freeing up the internal mechanisms and performing multiple testing scenarios we were confident the problem had been resolved which would allow the HV fault to then be rectified.
As previous maintenance on these LV breakers had been minimal, meaning the current on-site team had little experience and understanding of the established equipment, Quartzelec engineers believed equipment training would prove beneficial and was duly delivered to the NHS Trust team to ensure confidence and competence in the future operation of these LV breakers. Once HV supplies were back on, we were able to re instate the LV supply, the breakers went in and the supplies could be changed back over to mains supplies with full restoration of site supplies achieved. Checks were made to confirm phase rotation, Loop Impendence and PSCC readings.
A pre-negotiated contracting support agreement ensured immediate support:
"In the situation presented to us we were fortunate to have competent embedded Contractors who will go the extra mile for the Hospital and that is appreciated throughout" - Head of Maintenance, NHS Trust