Part 1 – Planning your standby power requirements

A good starting point when planning is to look at the strategic part that Standby Power plays. This part of the ‘IT Professional’s Guide to Standby Power’ will suggest some pointers that will help you evaluate the business needs in the company, and give some guidance on classifying your equipment into different categories for the degree of protection required.

Today most companies understand that the only way to guarantee the continuity of their business operations in the face of uncertain power supplies is to have a Standby Power strategy.

The type of business you have will govern the type and level of protection necessary to preserve not only the smooth running but also the reputation and profitability of your company.

Uncertain power quality

The uncertain quality of power drawn from the National Grid involves far more than power cuts. Momentary power interruptions, electrical current surges and also dips in power all create problems for sensitive electrical equipment.

Power failures are generally short-lived, though lengthy problems were experienced in the City of London during the summer of 2006, where demand for air conditioning resulted in the local electrical infrastructure being unable to keep up with demand. More recently, the severe flooding of 2007 in Yorkshire and Gloucestershire caught many companies unprepared when electrical substations were flooded. South Wales has a history of power quality problems and power outages or other problems are experienced periodically, countrywide.

Your Power Continuity Plan will reflect the nature of your business. For those companies where a power loss is no more than an inconvenience, it is common practice to install an uninterruptible power supply with a runtime sufficient to allow an orderly backup and shutdown of computers and servers.

For other companies, such as Data Centres and financial services organisations, where any downtime impacts severely on company reputation and profits, any loss of power will have severe implications.

Standby Power strategy

Therefore, having a Standby Power strategy, and understanding the full implications of that strategy, and how it will impact on the ongoing success of your business, is paramount.

Your strategy will need to cover more than the computer rooms, servers and communications equipment. Less sensitive equipment which can withstand short breaks in power may only need generator backup, but everything needs to be considered.

How long could your organisation continue to function without telephones? Emergency lighting, fire protection, access control, cooling for computer rooms and servers and auxiliary power for the building’s lifts all have to be evaluated.

Evaluating the business need

But how do you determine the continuity and recovery needs of your Business? How do you identify the critical business systems that need short-term power protection and those that need a long-term alternative power source?

As a starting point, you’ll probably find it beneficial to evaluate the risks that your business could face should different systems fail through either electrical instability affecting the power supply or a total loss of power.

Classifying your equipment

Looked at from a business need perspective, it becomes clear that different systems require different levels of power protection. This will allow you to categorise each piece of equipment according to the power protection that it requires.

‘Critical’ systems are those that cannot be allowed to fail. They must be kept operational for as long as possible, if not indefinitely. If the equipment was not designed to withstand power breaks of more than 4 or 5 milliseconds, it will certainly require an uninterruptible power supply (UPS). The UPS will condition incoming power and protect against relatively short periods of power loss. Extended periods will be covered by stored energy (typically additional UPS batteries) or locally generated energy (usually a diesel generator). ‘Critical’ systems require both UPS and generator Standby Power

‘Sensitive’ systems comprise electronic equipment which require a ‘clean’ shutdown and cannot withstand power fluctuations or the delay in starting up a generator. They require a UPS to provide power to the equipment whilst it shuts down cleanly and, if required, completes a backup. ‘Sensitive’ systems require UPS Standby Power

‘Essential’ systems are those that must be supplied with power in the event of a power failure but can withstand a short power interruption. This can be, depending on the type and size of the generator, a delay of between 15 to 30 seconds before the generator starts to support the electrical systems. There are other alternative sources of power, but a diesel generator is the most common. ‘Essential’ systems require generator Standby Power

‘Other’ electrical loads are those that can be allowed to fail and, in doing so, will not compromise critical systems, the health and safety of staff or customers, and will not damage the equipment in any way. ‘Other’ systems may not require any Standby Power

Equipment Categories

•’Critical’ systems require both UPS and generator Standby Power

•’Sensitive’ systems require UPS Standby Power

•’Essential’ systems require generator Standby Power

•’Other’ systems may not require any Standby Power

The IT Professionals Guide to Standby Power  – contents

A Glossary of Standby Power Terminology

Part 1 – Planning your Standby Power Requirements

Part 2 – Potential Power Quality Problems

Part 3 – Sizing Generators

Part 4 – Specifying UPS

Part 5 – Matching a generator to your UPS

Part 6 – Making the right generator choices

Part 7 – How to ensure your batteries don’t fail

Should you wish to discuss any of the issues raised in these articles, please contact us.

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