Healthcare-specific technical engineering guidance is a vital tool in the safe and efficient operation of healthcare facilities, so that if disturbances to mains power do occur, patient or staff safety is not in danger. The key challenges in protecting critical power in healthcare situations include:
Compliance with multiple guidelines, regulations, and healthcare-specific standards, including HTM 06-01.
Maintaining and expanding legacy estates incorporating equipment from multiple suppliers.
Handling the space, weight, and temperature demands of power protection systems in buildings rarely designed to house them.
Defining where Medical IT, UPS, and emergency lighting systems are needed, and then scheduling servicing.
High variations and/or continual growth in load
As healthcare facilities, and operating theatres in particular, rely heavily on technology for patient care, it is crucial to have reliable power protection solutions in place. There are many considerations on the most suitable systems, how they are designed to work together, and how they integrate with other legacy equipment. There are compliance requirements from HTM 06-01 and BS 7671 with regulation on the integration of a UPS into the electrical infrastructure to ensure a well-designed, reliable, and resilient system in a hospital or other medical facility.
Medical IT systems – evaluating risk to business continuity
With Medical IT systems, there is no standard ‘one size fits all’ solution. Estates and facilities managers, healthcare engineers, and system designers, must evaluate risk to business continuity, fault clearance, batteries, and selecting a UPS for Medical IT. This is not to mention a system’s carbon footprint, new installations, or who on the team has the correct technical knowledge to hand
Ensuring that critical power and backup is covered – to keep patients safe, and literally keep the lights on in medical facilities – is a big ask. Collaborating with suppliers and consultants who understand current and future challenges, and who can make this decision-making process much simpler, is as important as the vital signs routinely monitored by medical professionals and healthcare providers.
What sorts of power back-up are needed?
With hospitals and other medical facilities needing to be operational 24/7, the need for resilient back-up power solutions has never been greater. Even a short power failure can be extremely damaging to operational continuity, and, more importantly, patient safety. These problems can be avoided by using an uninterruptible power supply (UPS), which protects critical devices from power disturbances ranging from fluctuations, spikes, and dips, to total power failure. If the power goes out, a healthcare facility also has a duty of care to keep its people – patients, staff, visitors, and contractors – safe. Having robust life safety and emergency lighting protection is critical to ensure that evacuations can happen safely, critical procedures can be completed, and those unable to be evacuated in the case of an emergency can be properly cared for
UPS fundamentals: What are the requirements for UPS in healthcare settings?
The requirements for UPS in healthcare settings are set out in guidance that primarily includes HTM 06-01 and BS 7671. The requirements look at the load management for UPS, including considerations for power supply and redundancy, and can be found in HTM 06-01 Chapter 11 and BS 7671 Chapters 56 and 710.
Nowadays, ideally the power protection system comprises a modern, modular UPS system that can deliver greater power efficiency, as well as other benefits, including high availability and scalability. However, many sites have older legacy UPS systems – and these are where flexibility and energy reduction opportunities can mainly be found when systems are being reviewed and updated. Traditionally, UPS design centred on large individual standalone machines, which had to cover all the capacity required. Therefore, the whole system was always powered, and frequently would not be operating in its most efficient load band.
If redundancy was required, a complete additional system would be needed, further increasing the risk of sub-optimal loading. While a legacy UPS system may have a maximum efficiency of 93%, at 50% load this may fall to 90%, and to much lower – at 25% of maximum rated load.
Redundant capacity built in
Today’s designs are modular, where we can calculate and manage the load, so there is always redundant capacity for spikes in power usage. The UPS capacity originally provided needs only to exceed the actual load slightly, because it can be increased so easily, and incrementally, as and when the load grows. For example, users can start with a single cabinet with one 100 kW module (referred to as N), and have one more module included for redundancy (referred to as N+1). As the load grows, the UPS can be vertically or horizontally scaled (depending on the model) by adding additional modules, until the cabinet is up to its full kW capacity, and then additional cabinets as required. The ability to continuously ‘rightsize’ the UPS capacity to the load lets users minimise their power and cooling requirement, which consequently reduces power usage over the life of the UPS
Additionally, when we look at the load/ efficiency curves for modern, modular systems, we can see they are not entirely flat, but instead produce slightly higher efficiency at partial loads. This is because UPS manufacturers recognise that modular systems are typically operated in ‘redundant mode’, so no single module will be fully loaded. For example, in an N+1 system comprising two modules in parallel and sharing the load equally, neither will ever have more than 50% loading. The overall energy savings, over several years, from migrating to a modular UPS system from a poorly used legacy installation can be quite considerable.
Other equipment considerations
Medical Isolated Power Supply (MIPS)
As well as a UPS solution, a Medical IT, or Medical Isolated Power Supply system, will be required for operating theatres, intensive care rooms, MRI suites, recovery rooms, and therapy rooms, where isolated power is needed. Consideration for MIPS should include support, and compliance guidelines such as the requirements of UK HTM 06-01, as well as the integration with other UPS and generator systems installed in hospitals and other healthcare facilities.
What about batteries?
When considering the batteries required, you will need to carefully rate the system, as this will affect size, weight, operating costs, regulations, and end of life. Also, depending on what power is needed, there may be other systems in place that need to be considered and included for back-up
Battery failure is the most common cause of emergency power failures, so maintenance is essential. There are three key things that can affect a battery’s capacity. These are temperature control – too hot will reduce life, too cold will reduce performance, overcharging – which causes gassing, drying out, and potentially, thermal runaway, and undercharging – which causes sulphation and a loss of capacity. HTM 06-01 also makes the recommendation for 10-year batteries, and includes guidance on battery terminals and fire-retardant batteries
There are also two key things that will help extend a battery’s end of life and reliability – monitoring, which allows identification and the replacement of weak batteries, and active management systems that balance charging across batteries, preventing under/overcharging, and extending service life by up to 30%.
Emergency lighting
Healthcare environments are complex, and require emergency lighting that operates reliably when called upon, and provides sufficient illumination along all escape routes and to all other points where it is required. This can make the difference between safe management of a power disturbance, and panic, injury, or possibly even death. Emergency lighting is an essential part of any building services installation, and subject to extensive British and European legislation. The Department of Health’s HTM 06-01 document advises on healthcare electrical services, including emergency lighting. The guidance states that emergency lighting – escape, safety, and standby – should be designed to BS 5266-1 and BS EN 1838. Fully compliant equipment is required throughout healthcare buildings such as hospitals and clinics, covering escape routes to the ultimate place of safety, appropriate exit signage, and open area lighting – for example in science laboratories, retail units, and commercial catering.
Escape and safety lighting can be powered by central battery inverter units. However, operating theatres, which are risk grade A – the most critical – must have independent battery inverters for the operating theatre lamp(s) and satellite lamps
Emergency lighting, by definition, depends on a continuously charged battery back-up power source. The lighting set-up should be able to detect a mains power failure and switch to battery back-up automatically and immediately. The battery power source must be well-designed, well maintained, always fully charged and ready for use, and compliant to EN 50171 central system standard
System set-up
Carry out a risk assessment regularly. As part of your system set-up, audit the current and future power requirements so that you can estimate the load that you need to support with power – and, more critically, keep running should the mains power fail. Calculate how quickly the mains power will take to come back on, and review what needs back-up support until this happens. Is there equipment such as critical life care that needs its own power and back-up supply?
One way to look at this is to review the types of power required:
1. What are the medical requirements?
2. What are the lighting needs?
3. What mechanical equipment is already in place?
4. What emergency equipment is needed?
5. What requires isolating?
Once you have done this, you can look to see if the power requirement needs its own source, or whether it can be fed from the mains power. You will also need to check whether it requires single or dual source power to ensure that back-up will be comprehensive and meet compliance guidelines
Dual supplies for extra resilience
For extra resilience, dual supplies are provided at the final circuits, and each source may have a central UPS system configured for N+N. Generally, a central UPS will have a single source. A UPS at the final circuits may require dual sources. Having said this, no medical or healthcare facility is the same as another, so ensure that the risk assessment and equipment audits happen on a regular basis, are noted down, and communicated with the team, accordingly. Speak to your UPS supplier regularly, as it will be able to assist with the system design and changing requirements.
A key consideration for the system installation and maintenance is how the UPS will be monitored.
Will there be a:
monthly visual check?
daily visual check?
remote alarm signal?
BMS connection?
network and email connection?
remote monitoring by supplier?
Ensure that whatever plan is put in place is regularly reviewed, and – where possible – use your supplier as a critical friend to help with these audits.
Longer-term collaboration with suppliers
With healthcare, it’s better to think about longer-term collaborations with suppliers. The lifetime of a larger UPS is approximately 15 years. It will be due a major service every five years, where capacitors and fans will be replaced, and it should have a maintenance check twice a year. Batteries tend to need to be updated every seven and a half years.
Sometimes, we find customers are just not aware of system requirements or compliance. We see it as our job to supply and support – but also to educate. There have been developments in system design, technology, and product advancements, so we are getting more requests for advice. Installing your system requires thought and planning – for the technical requirements and physical positioning, so that customers can get the best use of the system and be assured of its reliability
Room planning and environment
UPS maintenance is critical, yet often, the positioning of units is not considered to ensure that the environment is optimal for performance and maintenance. When thinking about your site and your system design consider the positioning of your UPS.
Ideally, the space needs to be / have:
Clean and dust-free.
Dry.
At a controlled temperature.
Fire-protected.
Vibration-free.
An adequate air flow.
Manufacturer’s defined clearances for maintenance.
Is there a better, greener way?
Energy-saving ‘smart modes’ for UPS
Today, UPS systems can be run in smarter, energy-efficient modes. The challenge is working out which mode really works to offer you the ‘greener’ option. This can sometimes be confusing, as they all have different names, and no two ‘eco’ systems perform in the same way.
Some UPS systems run in an ‘eco’ mode. In this mode, the UPS remains in standby mode until the power is interrupted. Eco mode is suitable for equipment that will not be affected by a break in the power. It is often promoted, as it gives good headline efficiency figures, but is rarely used in practice as it doesn’t work where critical power is required.
There are also smart modes where the system manages the load across different modules and puts those not needed into standby. Kohler’s smart eco mode, known as Kohler Xtra VFI mode, is a great option for those who require critical power supply, but that have variable loads.
Often, when the load falls below 25%, UPS efficiency rapidly deteriorates. By automatically adjusting the number of active modules according to load and redundancy requirements, and reverting unneeded modules to standby, Xtra VFI avoids this.
Intelligent switching rotates active modules, equalising ageing, and extending service life. Kohler Xtra VFI mode offers 2-3% additional efficiency if the load drops. This option is included with the exceptionally resilient, flexible, and scalable (from 50kW – 1.5 MW), high power modular UPS KOHLER PW 9250DPA, which offers the bestin-market energy efficiency (97.4% efficiency) in regular VFI mode. This energy efficiency redefines the lifetime cost for high-density applications such as medical facilities – reducing environmental impact, optimising Power Usage Effectiveness (PUE) measures, and delivering significant financial savings in energy and cooling costs, without compromising the reliability of the power protection capabilities.
Seek a partner with in-depth knowledge
There are a lot of considerations and challenges installing and maintaining systems in an everchanging healthcare environment. Collaborating with suppliers and consultants who understand current and future challenges, and who can make this decision-making process much simpler, is vital. Ideally, you will want a partner with in-depth knowledge, extensive experience, and a comprehensive choice of solutions that will fit the healthcare facility’s specific needs.
Kohler Uninterruptible Power and Alex Emms
Backed by Kohler Co’s 100+ years of power protection experience and innovation, Kohler Uninterruptible Power is well resourced and well positioned to provide the necessary depth of advice and support. It provides expertise, remote support facilities, and an extensive network of field service engineers ‘offering fast, 24/7 availability.’
Alex Emms is Technical director at Kohler Uninterruptible Power. He has over 30 years’ experience of the UK power protection sector, and has been with KUP since 2000. Starting as a Field Service engineer, he subsequently progressed to roles including senior engineer, Supervisor, Service manager, Operations director, and now Technical director