Business Continuity

Protecting against power issues in a small office takes more than picking a UPS

Protect computers from power problems and you can extend their working life as well as avoiding downtime and possible data corruption. Losing data on a laptop or desktop is bad enough, but losing a server to a power surge or power cut can be much more severe, potentially even a threat to the business. Losing a mail server or a major database can lead to serious data corruption that will take you time, perhaps even days, to resolve. During that time, your customer’s business is being impacted, and even if they’ve ignored your advice they’re likely to blame you, so you need to explain the danger and convince them to protect their systems.

As robust as modern power supply units are, a power surge can blow the internal fuse. This is not a user-maintained part and requires a whole new power supply. Don’t ignore other equipment when you suggest power protection. Fax machines, printers, copiers, broadband equipment, firewalls – these should all be given just as much protection as computers. After all, if the DSL modem fails it means no communications until you replace and reconfigure it. A firewall failure means taking the time to bypass the failed component and either working with no security protection or having no connection until a replacement arrives.


Some risks are worse for businesses outside major towns. Power lines can come down in high winds and storms; falling trees can take out power and telephony simultaneously and restoring service can take days. Increasingly, thieves are damaging power lines and breaking into sub stations to remove high-value copper cable.

Power fluctuation and noise

Any cable can be affected by noise and electrical cabling is no different. The most common cause is degradation in the quality of the power supply caused by supply fluctuations – through unexpected high demand, problems at sub-stations or faulty transmission equipment. A less frequent cause is the weather; high electro-magnetic storms in the atmosphere affect power grids.


Power surges can be as high as 30,000 volts. These can fry circuit boards and blow power supplies. Power fluctuations causing low voltage can cause equipment to trip and reset. In the worst case this will blow mains fuses. Alternatively, they may be severe enough to cause a series of mini power outages. The latter are the more damaging as they will result in equipment starting and stopping, overloading or causing hardware failure.


Inside the office, if a server shares its electrical supply with other equipment such as vending machines or even a kettle, when they are used they add noise to the electrical circuit.


Unless the customer’s office is in a modern building, there can be questions over the wiring. Too many devices on a single circuit can create heat in the wires with a risk of fire, so watch out if you’re always tripping over extension leads. If a power surge causes multiple devices to reset, the increased load can force a fuse to blow and take out the power that way. Consider how devices are connected and try to ensure that those devices that are likely to place excess loading on the circuit are evenly spread across multiple circuits.

Work on the wiring

Find an electrician to work with who understands IT and get the customer’s wiring checked. Not only will they provide advice on splitting loads over different circuits, they will be able to check earthing and upgrade fuses if appropriate.


A yearly health and safety check of electrical equipment tends to only focus on devices but a regular check of cabling can also pay dividends. Drawing excessive load over a sustained period of time can lead to fires inside electrical wiring. Run a power check to see how much power is being drawn off of each circuit to see where there’s a risk. Whenever a fuse blows, don’t just change the fuse; check the wall socket for damage.


Identify which circuits are being used for IT equipment and, if necessary, mark each outlet ‘for IT equipment only’. This should help keep kettles and other causes of electrical noise away from essential hardware (make sure the business provides other power outlets where necessary). The more devices they plug in, the more noise, so think about ways of limiting the number of devices in use.


Consider moving the client to three-phase power. This allows the load to be split not just over multiple internal electrical circuits but over external circuits as well. You can then allocate a single phase just for the servers. This helps to reduce line noise from affecting all equipment.


To understand the power load on a particular cable, use an ammeter or power meter. You can attach an ammeter to a cable so it’s easier to work with in tight spaces; a power meter has to be connected inline at the socket or at the equipment to provide a measurement.

Protecting PCs and more

The simplest way of protecting unused equipment, both during the day and at night, is to turn it off; which also reduces power costs. Turning hardware on and off is still a contentious issue because the greatest stress on hardware is during that start-up period. This is also the time when hardware uses the most power.


Older generations of hardware suffered from risks of failure due to the stress of powering on. For any equipment purchased in the last few years, that is no longer the case and the main complaint is inconvenience. There is still a small increase in power when the hardware starts and there is a period of time lost while it starts up but even the increased power use is cheaper than leaving hardware on for long periods of time when unused. Similarly, printers can use consumables when starting up but this is a very small amount and economical compared to the cost of keeping them powered on doing nothing. Overnight, apart from servers receiving email or supporting remote staff, there is no case for leaving hardware turned on when there is no-one in the office.


Surge-protected power sockets are cheap enough for the smallest office; you can put protection at the power socket or even add it as a feature to the fuse box. The danger with the latter is that micro-trips, which are important safety features, can be inadvertently tripped if too many devices are turned on at once. The micro-trip can see this as a dangerous surge and trip the fuse. The result is everything loses power.


The number of devices installed in offices these days means few people are plugged directly into the wall socket any more. Most use a multi-plug block to allow several devices to share a single mains socket. Using a surge protector at the wall socket or only using multi-blocks with built-in surge protection will remove the risk of surges. Ensure you test the surge protector at least once a year in order to meet health and safety rules. Power strips from Belkin, Maplin and even Currys provide surge protection for all electrical equipment, but some come with telephone ports so you can protect a desktop PC, desk phone, fax and DSL equipment together.


For a small office server, vendors such as Avocent have power strips with surge protection that will also tell you how much power is being used. You can even access these strips remotely using Avocent’s software and hard reset a computer without visiting the site. This can be a big time saver but it also allows you to remotely manage and monitor how much power the servers are drawing.

Uninterruptible Power Supplies

A UPS is simply a box of batteries that provide you with a limited supply of power when
the mains power fails. They also act as surge protectors and power cleaners. The UPS sits between the mains socket and the computer hardware; when the power fails the UPS keeps the computer running long enough for you to shut down gracefully, saving data and stopping services.


While it sounds easy, it takes planning. There’s a limited amount of power a UPS can provide and if it can’t support the load you connect, there’s no point in having it at all. There are rules of thumb – a 2kVA UPS will run the average tower server but you need a 6kVA UPS to cope with a rack-mount cabinet. But the IT needs of offices vary so widely, that it’s safer to use power calculators from vendors such as APC (which you can find below) to size the load and set the amount of protection that you want – from 10 minutes to several hours.


Rather than putting in lots of individual UPS units for a small office, it is better to have the electrical supply configured so the sockets going to key equipment all come off of a main UPS. Be careful of over-loading this circuit and ensure that the client has alternative circuits for kettles and other less critical equipment.


Ideally the UPS for servers should be installed with them, in a small rack. The servers then connect to the UPS or to a managed power strip from a vendor such as Avocent. One server should be connected to the UPS using a serial cable, allowing you to configure and monitor the UPS. To properly manage a UPS under Windows Server, turn on the UPS service. The UPS needs to protect the servers for long enough to enable a complete shutdown of all computers. Most UPS vendors have management tools that will use automated tools to gracefully shut down hardware when the power fails, but you still need to know how long it will take so you can configure the UPS and servers properly.


The UPS alarm should be set to inform both the customer’s on-site IT team (or whoever has responsibility for the IT equipment alongside their normal job) and your own support team. Set the alarm status on the UPS so that you have time to respond to a power failure. Unless you’re close enough to reach the office in time, you will want to run a script that shuts down the servers when the UPS alarm goes off.


The main reason why UPS alarms don’t work as expected is because key equipment isn’t connected to the UPS. The ADSL modem, firewall and any other hardware that control access to the outside world must be powered by the UPS or the alarm won’t get to you.


Even so, there’s always the risk that when the power goes down, so do the telephone and network connections. Although there has been discussion about putting SIM sockets inside UPS cases so they could use the mobile network, no vendor is currently shipping a device with one. Instead, look at firewall appliances such as the SonicWALL TZ 190 which will act as a firewall and wireless router. It comes with a 3G Wireless WAN slot. When the primary circuit fails and mains power is lost, provided the TZ 190 is powered by the UPS you will still be able to have the system send emergency messages to alert you to the problem. The TZ 190 can also be managed centrally, allowing you to offer security monitoring to your client.

Power generators

Some customers will rely so much on their IT that they’ll need a power generator because they absolutely must keep the systems running, although you should explore other options including failing over to an external hosted service and having a secondary office available. If the power is unavailable for long enough for a generator to be useful, there may be related problems that make the main office unusable anyway.


Generators are an emergency replacement for the mains service and like UPS, need to be carefully sized and regularly maintained. As there will be a delay between the mains power going down and the generator starting up, you’ll need a UPS with enough battery capability to cover the switchover.
As the generator will replace the mains service, it needs to supply power through the UPS to the hardware. This will also clean the power and recharge the UPS. Unless you are installing industrial-scale generators, as with a UPS, you need to be firm when deciding what is going to be supported by the generator. Desktop computers, with the exception of a small number of key workers, will not be important. Printers, fax machines, kettles and other electrical equipment should only be connected to the generator circuit in an emergency (and make sure employees know that ‘needing a cup of tea’ is not an emergency).


Generators should be checked on a regular basis and the business will have to keep enough fuel on hand to run them. Be careful with fuel storage. Some fuels, such as diesel, cannot be stored for long periods without causing problems. Any fuel storage for a generator will need local authority planning permission and the business will have to provide a secure storage point. It is also important to point out to them that storing fuel can increase the likelihood of theft, as the rising cost of fuel makes it a prime target for thieves.

Co-location and hosting

In many cases, a better option will be to locate key customer servers outside of their facility in a hosting or co-location facility (alternatively, you could provide the servers and sell them space and access). These locations are geared up to provide emergency services in the event of a power outage and they have the advantage of having multiple network connections to protect against any network failure.


There are costs involved but for key services such as email, this provides an additional peace of mind. After all, if there is no power, no-one will be coming to work. At least, with email in a managed location where power is effectively guaranteed, staff can connect from home and the client can run a limited business function.


Protecting power should be a standard part of your service to customers. Predictions of power shortages may be nothing more than panic mongering but power surges and power failures from equipment failure, workers cutting cables and weather happen every day. There’s no need to be alarmist. Treat this as a business continuity issue and help your customers plan ahead to deal with problems before they happen.

APC UPS sizing calculator

Size UPS protection by devices or load, individuals PCs, or a mix of PCs and devices. The VA (Volt Amp) ratings should apply to any manufacturer’s UPS models.

UPS sizing tool for Dell and Cisco

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