One topic of universal concern created by the Covid-19 crisis is the pressure being felt by NHS staff of all disciplines. While risking their own safety and working in demanding conditions they also have the constant worry of being overwhelmed if admission rates increase excessively. This of course is the reason behind the regularly-broadcast Government mantra; “Stay at home, protect the NHS, save lives”.
Power problems can occur anywhere, anytime, in any electrical system, regardless of the design standards employed. Accordingly, it may be tempting to build in the highest possible resilience across an entire healthcare estate to avoid any risk to patient safety or business continuity arising from a power loss. However, real-world budgetary or space constraints typically make this approach unrealistic. In developing or reviewing policies to support critical life-supporting equipment, and other less-obviously critical yet still essential equipment, healthcare estate managers should consider the guidelines given by the Department of Health’s Health Technical Memorandum (HTM) 06-01: ‘Electrical Services supply and distribution’ document[i]. It details how to design in solutions that carefully balance each area’s critical resiliency needs against costs.
Your protected power system vendor can help
Kohler Uninterruptible Power can advise health estate managers on how to meet the guidelines, as more fully detailed within the HTM 06-01 document, and economically achieve the levels of resilience appropriate to both critical and other areas of the facility. This includes not only specifying UPSs in terms of their redundancy levels, capacity and battery autonomy, but also on how to integrate them into existing power structures and include generators if appropriate. We can also discuss steps to ensure ongoing support in this currently challenging and uncertain environment.
HTM 06-01 in more detail
HTM 06-01 is a component of the Government’s Health Technical Memoranda, which provides comprehensive advice and guidance on the specialised building and engineering technology used in healthcare delivery. The design process should verify that single points of failure leading to loss of electricity supply are minimised by providing the appropriate level of resilience at the point of use.
HTM 06-01 defines three power supplies for use across a healthcare estate: Primary, typically from the energy supply company – this is supplemented by a secondary supply, such as a generator or batteries. A tertiary power supply, in the form of a UPS or battery system, constitutes a further supplement. The memorandum considers two aspects of risk arising from a power outage:
- Clinical risk (subdivided into patient and non-patient areas); Clinical risk grading is form E (Lowest) to A (highest)
- Non-clinical business continuity risks (subdivided into medical services and engineering services). Gradings are from IV (Lowest) to I (Highest)
The intensive care units coming under pressure today are classified as ‘Risk grade A – the highest -covering life support, operating theatre suites, catheterising rooms, accident & emergency resuscitation units, MRI and other locations. Where supply disconnection represents a threat to life, an alternative source such as a UPS must be available within 0.5s or as a no-break supply if critical medical electrical (ME) equipment will not continue to function without a reset after a 0.5s break.
Other engineering services that support clinical treatment should be connected to the secondary supply within 15s of any electrical supply interruption.
Overall, HTM 06-01’s view is that: “The required system resilience can be achieved in two basic ways: first, by having an alternative power supply and, second, by having alternative distribution cables and/or routes; both may be engaged by automatic changeover with manual bypass.”
The document also states that this resilience can be enhanced at the final distribution board with the use of tertiary power supplies such as UPSs. Additionally, the risk classifications note the role of generators in limiting electrical supply interruptions.