Uninterruptable Power Supply

What is a UPS and do I need one ?

UPS (short for Uninterruptable Power Supply) is a very big battery with some clever electronics that you insert between your computer and its mains power supply. It has two functions

1. It smoothes out any ‘bumps’ in your power supply voltage – spikes and brief dips in the power
2. If there is a power cut, it keeps your computer running long enough to shut down cleanly

So it is a protection device to prevent damage to computer hardware, your systems and your data. Put plainly power spikes are bad for their power supplies and sudden power loss is very bad for your systems and data as this can cause corruption resulting in the need to recover data from backup or possibly data loss. Serious data loss can render your computer inoperable, unbootable.

Now if your computer is a desktop PC you probably only want to invest in a UPS if the cost of having to recover from an expected power problem makes it worthwhile for you. If your PC is essential – maybe you are a smaller business where everything is on your PC, then you should consider this. If your PC is a laptop – it already has a battery to keep it going !

Of course most businesses put their key systems and data onto more powerful central servers. In our opinion it is essential to protect your servers with a UPS. Even a medium size server can hold a lot of information – if you need to restore its data after a power failure has caused corruption then this could easily take hours just to get the data from the backup tape. This assumes the power problem did not physically damage anything. A serious power cut – even a self inflicted one caused by tripping a breaker eg putting the kettle on – can bring a business to a standstill.

Top Tip - put your servers and network equipment on a different power circuit, ideally on their own.

When you get your power back you want to be up and running and recovering from the outage as soon as possible – not spending hours repairing your servers or recovering your systems and/or data.

UPSs come in different ratings – the higher the rating the more power it can supply. You can get quite compact UPSs to protect a PC and larger tower or rack mounted units for protecting servers. When selecting a UPS you should get advice on rating the power requirement of your equipment and work out how long you want the UPS to run your equipment during a power cut in order to correctly specify the size of UPS you need.

UPSs have a data connection to the computers that it protects so it can tell them when the power goes off and if it needs them to shut down. When the power comes back on you can specify a delay to ensure that the power is stable before the UPS automatically restarts everything.

UPSs can be very sophisticated, constantly monitoring the quality of your power and taking intelligent decisions when there are problems. I can recall one situation at a large site where the UPS was so big it had its own little building, the power to the site kept failing due to a faulty breaker and in the middle of the chaos a van with two engineers from the UPS company arrived unexpectedly. Apparently the UPSs electronic brain had noted the problems and phoned them……