In August 2019, Ipswich Hospital was plunged into darkness after it was hit during a 15-minute UK-wide power outage.

The trust revealed that the disruption caused the unit’s circuit breaker to fail, briefly cutting the electrical supply to outpatients and the X-ray department. Luckily, the hospital’s back-up generators took over and prevented risk to both patients and life-saving medical equipment.

Not surprisingly, the incident has exposed the importance of back-up power technology and how it is operated.

Chris Rason, managing director of Aggreko UK said, “Ipswich Hospital provided a stark reminder that if there is a fault with the circuits; then the back-up power will simply fail. Downtime, whether caused by power or equipment failure, has a large impact on the healthcare industry. It can result in appointments being cancelled and frustrated patients, ultimately leading to reputational damage that can take months to repair.” 
 

Keeping the power running can be a matter of life and death

Andrew Keith, product development director at power resistor manufacturer Cressall Resistors said, “The failure of an electrical supply network for healthcare facilities is a matter of life and death. While power back-up failure is extremely rare, especially in developed countries, there have been incidents that have resulted in surgeons operating by torchlight and staff having to manually remove fluid from the lungs of intensive care patients. With lives at stake, even one power failure is too many.”

Having a standby power supply plan in place is essential

Standby power normally comes in the form of batteries, generating-sets, or a combination of the two.  

A battery-powered uninterruptible power supply can instantaneously take over if the regular power supply fails. There would also normally be a diesel generator that runs for as long as there is a fuel source. Its purpose is to take over as medium-term supply once the battery has managed the immediate problem.

“Supplying sufficient fuel for the generator to run for an extended period is the first and most basic requirement”, explains Keith.

Maintenance and testing of a standby power supply is critical

Keith points out the importance of maintenance tasks, such as visual inspections and regular generator testing, and warns that “It is obviously not acceptable to interrupt the power supply to a hospital once a month to connect the generator and run a test. However, simply turning on the generator occasionally is not sufficient. It must be run under load to ensure it will perform as required in the event of a mains failure".

"In addition, diesel engines that regularly run on very low loads - or even no load at all - become increasingly unreliable, and effects such as smoky exhausts and carbon build-up further impact their dependability.  

“Installing a fixed load bank to the back-up generator does not only justify a saving in the maintenance cost of the generator’s life; but also greatly improves the likelihood of it running efficiently in the event of a power emergency”, said Keith.

Remember the memoranda

Memoranda HTM06-01 provides guidance for all works on the fixed wiring and integral electrical equipment used for electrical services in healthcare premises. And it should be applied to all forms of electrical design work, from greenfield sites to modifying an existing final sub circuit.

Specific operational management and maintenance directives
Memoranda HTM06-01 stipulates the following for all standby generators in any healthcare facility:

• That they should be tested every month for a duration of at least one hour.
  
  
• The generator being tested should operate at greater than 70% full load.
  And, where the back-up generators do not have grid synchronisation connection, the only way to test the generator is with a load bank.
  
  
• That maintenance programmes should also include a longer test to establish the generator engine’s mechanical performance as well as a test to prove the generator’s condition up to 110% full load.
  
  
• These tests should be carried out annually for a test period of no less than three hours.

Keith explains, “The optimal test would be performed at a representative power factor such as 0.8, which requires a load bank with both resistive and reactive sections. This will ensure the generators alternator is tested to full load current.”

He adds: “In a healthcare application, using building loads alone to test a generator is not desirable because the load is uncontrollable, unlike load banks which have precise load steps, making it problematic to sustain the load above the required level for the duration of the test.

Saving lives with effective load bank testing

Keih warns that the biggest mistake is to assume you can sufficiently check a generator by simply turning it on with no load or a low building load.

“Low loading would not comply with maintenance standards. It often can lead to generator ‘wet stacking’ - a condition in which unburned fuel passes into the exhaust system in diesel engine exhaust systems. This low loading impacts the integrity and service life for any generator.

“Using load banks for generator testing and maintenance provides certainty when streamlining compliance testing with reliable performance monitoring.

For any standby generator, routine testing that includes on-load running to bring the equipment up to normal working temperatures means a much-higher certainty that it will perform as expected during a real power outage.

“With effective load bank testing in place, healthcare facilities can continue to save lives - minus the torches.” he states.

Back-up supply testing advice from Finning UK

Jason Harryman, sales and business development manager for electric-powered diesel at
Finning UK takes a similar fail-safe approach.  

Following the Ipswich outage, the company advised healthcare operators to consider three main issues in order to check their back-up supply:

Weekly testing
This should include any moving parts within the generator itself. 

Back-up generator tests should cover:

• Battery voltage.
  Harryman says. “A measurement of the battery voltage during start-up will reveal whether any problems are potentially on the way. For example, if battery voltage is too low, then a back-up generator may not be able to start quickly enough in the case of a power outage, which could lead to serious and costly repercussions.”
  
  
• Controller issues.
  He advises healthcare estates and facilities teams to prioritise any issues identified by the back-up generator’s controller. “Check regularly that no reporting faults have been identified and, if they have, then deal with these as a priority,” he said. “It is critical that any potential issues that the system’s controller might identify around the standby temperature, for example, are investigated.
  
  “A hot engine for standby is needed as it will then deliver load better than from a cold start should sites be faced with a power outage.” But, he warns: “Generators designed to operate from standby will only come online in the event of an emergency. Therefore, they are not in regular use and may not be subjected to the same stringent inspection regimes as other capital plant.
  
  “When not in use, for instance, a back-up generator’s fuel can become a common issue if preventative measures are not taken, as fuel can become contaminated by water condensation, dirt ingress or rust over time. This can lead to filter blockages, or premature wear of fuel injectors or pumps. “As a result, it is crucial that the appropriate equipment inspections are taking place.”

Back-up for your back-up with SLAs
Harryman advises trusts to ensure the service level agreement (SLA) they have in place with their back-up power equipment provider is fit for purpose and at an appropriate level to meet demand.

He said: “An SLA means critical infrastructure providers can be confident that they can rely on repair and maintenance expertise from a trusted supplier so back-up generators will remain operational no matter what the circumstances are. This provides sites with assured peace of mind, as well as fixed budgeting costs.

“Many believe that their SLA will automatically cover emergency call-outs, which is a common misconception. Opting for a more cost-effective SLA, may not provide the site with the repair and maintenance support needed. Trusts can erroneously believe they have the in-house skills and capabilities to deal with any potential generator issues, and the decision has been made as part of a cost-saving exercise. “Therefore, it is always recommended that operators check the terms of their SLA and ensure it meets their site’s demands.

“Users should seek a trusted partner with a strong track record of delivering reliable back-up systems and which considers each site’s individual requirements.”

The threat of freak weather conditions

The warning that freak weather incidents such as extreme heatwaves and flooding are set to increase should be another reason for estates managers to ensure systems are fit for purpose.

A recent report by Aggreko entitled Planning for failure: How robust is your power contingency plan? states: “Forecasters expect the UK and Europe to continue experiences further extreme weather conditions and organisations must act now in order to prepare for overheating and system failure.”

It advises trusts to carry out site surveys and ensure effective contingency plans are in place.

Mitigating risks in an unpredictable future

“We cannot predict the future, but we can ensure that any risk associated with power outage is mitigated,” said Rason.

Harryman concludes: “Back-up generators require regular maintenance and testing to ensure they are operating properly, and this should be supported by a suitable SLA.

“By taking these steps, healthcare providers can be confident that they have taken every precaution and have the right provisions in place should a power outage, such as the one experienced in the summer in large areas of England and Wales, occur.”