» UPS power protection and the levels of cover they provide «
Surge and UPS devices, an overview
Level 1 protection: Surge protection
There isn't actually a category for this, so I've created one. If there was, this is where surge protection plugs and sockets would sit. Surge protectors have there own section shortly, but in general, they should be viewed as an additional weapon in the armoury and not something you want to guard a critical server with.
These should at least protect against the following:
3. Power Surge
Level 3 protection: Off-line / Standby UPS solutions:
These should protect against the following:
1. Power Failure
2. Power Sag
3. Power Surge
Level 5 protection: Line-interactive UPS solutions:
These should additionally protect against the following:
4. Under voltage - brownouts
5. Over voltage - spikes
Level 9 protection: On-line UPS solutions
This is the best readily available protection and, as well as all the above, should guard against these:
6. Switching transients
7. Line noise
8. Frequency variations
9. Harmonic distortions
What is a UPS?
At the very simplest level, it is a battery that filters the mains power reaching your computer.
Which type might I be best with ?
As seen above, these are three main types, offering incrementally better protection.
Starting around £35, the budget offering covering level 3 protection.
These are adequate for home computers.
This is basically a token protection against power outages and, for the price difference, I really recommend going up to a line interactive if you can afford to, though it is infinitely better than nothing. In it's defence, a good quality one will react fast enough when it matters and they are the quiet and efficient (they don't use a lot of electricity to run).
Line Interactive UPS
Starting around £55, these offer level 5 protection (or better)
These are generally great for homes, offices and none critical servers.
As I said, for the small price difference, I really don't see the point in off-line. As well as offering better line filtration though AVR (Automatic Voltage Regulation), they convert a trickle of DC power to the battery to keep it fully charged at all times. Line interactive are also the most cost efficient.
'On line or 'Double-Conversion' UPS
Starting around £500, these give full level 9 protection.
These are for critical applications, equipment and servers (and the paranoid like me
).As well as filtering all nine line disturbances, and continually charging the battery source, the method it uses feeds power back out into another AC/DC regulator/inverter so that the resulting voltage is separate from the incoming mains supply. If the power goes down, backup is instantaneously available, with no start up or switching required. However, they can be costly to run.
