Backup power is an integral part of a company's operations, providing support throughout maintenance activity and in an emergency. in addition, the use of temporary backup power can often have financial benefits for businesses. Tommy Conway, a technical support manager from Aggreko, looks at the issues around specifying backup power
The use of backup power is relevant for practically every industry and business, from manufacturing to data centres, hospitals and storage facilities. For projects within these areas, the use of temporary power can have significant benefits not only for the electrical contractor but also for the client.
With all its associated costs of labour, materials and downtime, maintenance can be a serious drain on the running of any business, particularly if it involves disconnecting the source of power, for example when working on a site's transformer or switchgear. However, the situation can be greatly eased with the use of backup power, which can provide a reliable source of temporary power and act as the utility provider to allow the company to continue operating throughout the maintenance period.
In addition to maintenance support, contractors can use temporary generators for vital system testing and in the commissioning stages of a project. Loadbanks can be used to check a company's own backup supplies, if they have UPS systems or onsite generators, for example. While it may be possible to conduct ‘live' loadtesting, where the mains power supply is literally switched off to check that backup systems kick-in, for some businesses such as hospitals and data centres this form of testing will not be possible, as their systems or operations rely heavily on having a constant source of power. In these cases, loadbanks can be hooked up to the backup power supply to simulate a situation as if the mains power supply had failed. This will help to test the reliability of the support equipment, providing clients with the assurance that in the event of an incident affecting their power supply, they can continue to operate.
Some applications will need temporary power in the commissioning stages to demonstrate to the client they are fully functioning and to check they are in full working order before final sign-off of the project. In addition, some technologies, for example gas turbines and Combined Heat and Power (CHP) units, need ‘exciting' with a temporary power supply to help them start to generate their own power as part of the commissioning stage.
While electrical contractors can recognise the benefits of using backup power for temporary situations, it may not always be as easy for the client who has to pay the bill. However, temporary equipment offers businesses a range of financial benefits. It allows capital to be retained for core business activities, as the provision of equipment over the short term is often financed out of operating or maintenance budgets, which helps customers to avoid time-consuming capital approval processes.
In addition, payments can be budgeted on a monthly basis, which can be a significant bonus for companies when managing their cash flow. And because the situation is temporary, should circumstances change, the equipment can be easily returned with no obligation. Also, should it be that more power is required, an additional generator can be on site promptly.
Power disruption is the fastest growing down-time threat to UK organisations, and time lost to such disruptions increased by more than 350 per cent between 2005 and 2006*. With this in mind, electrical contractors are well placed to educate clients on the benefits of contingency planning. In fact, many do not know there is a British Standard around contingency planning.
British Standard BS 25999 was launched in July 2007 and is a code of practice highlighting what organisations must do to ensure their business continuity management systems are running effectively. By following such guidelines, businesses can keep going during the most challenging and unexpected circumstances. It will also protect staff and bolster the company's reputation.
In order to gain the standard, organisations need to have contingency plans in place to ensure that in the event of power loss, the business can keep running. One option is to devise a plan whereby temporary generators are kept on site to start up when power is lost. For certification, there needs to be a clearly structured contingency plan, with a document outlining the process of restoring power. Simply having a temporary generator on site is not enough to comply: the generator needs to be maintained and serviced and contingency plans need to be implemented by a knowledgeable and experienced specialist company.
There are two options available when setting up a generator, depending on whether or not the client can go without power for a very short period. If he can, then it is possible to run a generator with an Automatic Mains Failure panel (AMF) which monitors incoming power supply from the mains grid. In the event this is disconnected, the AMF panel will start a standby generator. When the original supply is reinstated, the panel switches back to monitoring the mains supply and stops the generator.
With this set-up there are breaks both when the generator first starts and when it stops. This option is ideal as part of a planned maintenance programme, which can be conducted at periods of low production when the interruption is less critical or when the client knows their power is going to be disconnected.
Alternatively, if going without power is a major problem - which may be the case where it affects manufacturing processes and the quality of an end product; or in the case of a data centre, where records and information could be lost - then it is possible to use generators that can recognise when there is no mains power supply and then take over. Zero synchronisation, as it is known, involves installing generators that continuously run, monitoring the electricity waves from the grid. The generator is synchronised to three phase 50Hz with the grid, so that having recognised there is a dip in power supply, it automatically takes over the load. This means the company can continue to run, minimising downtime and protecting any process that requires constant operation.
When specifying a generator, working with a specialist company is key. This is because with a generator - as with any other machine that provides power to a process - output needs to meet demand for it to work efficiently. Using a generator that is over-sized for the amount of energy required and working under capacity can cause just as many problems as a machine that is not producing enough power. It is necessary to consider the type of load demand of the premises - such as low power loads, leading power factor loads and total harmonic distortion (THD) - which can otherwise have a detrimental effect on switchgear, cabling and alternators.
As well as considering the size of generator required to meet the company's energy needs, it is important to plan the location of the generator. If, say, it needs to be situated close to the point of use, this may dictate the need for silenced canopied generators, which lower the noise level of the machine. Other important considerations include the specification of cabling and pipework - which carry the load to the point of use - fuel supply and compliance with the G59 regulations, which cover the use of generating plant running in parallel with the grid.
The use of temporary backup power provides a viable solution for so many situations that can threaten a company's operations. Whether during maintenance or to cope with power emergencies, it is a technology that electrical contractors should use to their advantage to help minimise disruption to their clients' businesses.
*According to research by SunGard Availability
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