How would you feel if someone pulled
the power cable out of your Mac (or PC) right now, without warning? If
there was a power failure this is effectively what would happen, and you
could lose data or your entire computer as a result.
Guard yourself against such an event with a UPS device.
An uninterruptible power supply, or UPS for short, is, in a nutshell, a heavy-duty mains-charged battery unit that sits between your Mac and the regular power sockets. These devices are designed to provide enough electricity during a power cut to keep connected equipment going for a little while, normally providing five or ten minutes of power for a few devices; long enough to save work in progress and shut down gracefully.
Most people think of these as something you’d need only if you lived where power cuts were a common occurrence. However, even in the middle of a busy city your power could fail for any number of reasons, from a simple blown fuse to roadworks problems, lightning strikes (they do happen), and so on. If the power fails your Mac will go down without warning. Not only will you not have a chance to save your work, the OS won’t have performed a graceful shutdown; you may need to run disk repair tools as a result. If you're unlucky your computer could suffer expensive hardware damage as well. Wherever you live, if you use computers, a UPS is well worth considering.
Another benefit you’ll get from a UPS device are ‘line conditioning’ features. Generally referred to as automatic voltage regulation, these tame fluctuations in your mains power. Although you would expect your incoming electricity supply to give you an unvarying 240v current (or whatever is standard for your part of the world), it will actually fluctuate from time to time. You may have noticed your lights dim for half a second once in a while; that’s a crude visual symptom of the effects of ‘dirty’, unregulated power. This can cause stress to sensitive electronic equipment. Although it is generally soaked up by the poswer supply units within your IT equipment, it will still take its toll on those components at least, and can lead to crashes and freezes. Automatic voltage regulation curcuits are designed to take such spikes and troughs in their stride and pass a tamed result on to connected equipment.
When choosing a UPS device, make sure that you pick one which will be able to handle the demands of everything you want protected. UPS suppliers will normally help you work out what level of device you need, but if not you can work it out yourself with some simple maths. Next to the power socket on Macs, PCs and virtually all other IT equipment you’ll find the item’s amps rating. Multiply that by the mains voltage and you’ve got the VA rating; volts x amps = VA. (VA is also commonly called watts, although an electrician will point out that there’s a difference between the two.) If necessary, divide the VA figure by the UPS device’s capacity and you’ll have the length of time its battery can maintain those items on its own; VA / capacity = uptime. If you prefer, a UPS capacity calculator can be found at CSGNetwork.com.
When looking through catalogues don’t go by a manufacturer’s quoted maximum battery running time; that will be calculated with the minimum load rather than a realistic one of the device under full load. Make sure you get a unit which has 25% or more VA capacity than your existing needs. This will ensure you get a bit more than the minimum amount of time when running from the battery, and it also gives you scope for using slightly higher-rated equipment in the future without risking the UPS failing to keep you running in a crisis.
Remember, having a UPS doesn’t mean you can keep working even if the mains power fails. These devices are meant to provide enough time to sort things out, not to let you carry on with your work as if nothing’s happened. Only use a UPS for items which really must be kept alive for a short time if the power fails. Anything which pulls a lot of power shouldn’t be connected via one of these unless absolutely necessary. Your monitor is a logical choice, as are any external hard drives. Other devices are less necessary; for example, scanners don’t need the UPS treatment. Laser printers will stress a UPS’s throughput quite heavily, especially when first turned on. Remember, if there’s a power failure your main concern should be in saving your work and shutting down gracefully, not in making a few prints. If you’d like to have your laser printer protected from fluctuations in mains power then by all means connect it to the surge-protection sockets. These flatten out power spikes, causing less stress to the electronics and providing protection against lighting strike pulses. Just don’t hook it up to the battery-backed sockets or you’ll shorten the life of the UPS itself.
When there’s a power failure your UPS device will start beeping to let you know that it, or rather your computer, is running on battery power. Most units will offer extra connections to your Mac or PC via USB or Ethernet, and can, in conjunction with bundled software, automate the process of shutting it down. This is ideal for unattended servers, but it can also be useful if you happen to be away from your Mac when the power fails. Some UPS devices come with Windows-only software and PC-specific serial connections, but there are utilities for OS X that can work with these, even if a USB-to-serial adaptor is used. Aside from this, any UPS hardware will work with Macs as well as PCs, as it simply provides temporary power when needed.
This article copied from www.thesmallest.com.
Guard yourself against such an event with a UPS device.
An uninterruptible power supply, or UPS for short, is, in a nutshell, a heavy-duty mains-charged battery unit that sits between your Mac and the regular power sockets. These devices are designed to provide enough electricity during a power cut to keep connected equipment going for a little while, normally providing five or ten minutes of power for a few devices; long enough to save work in progress and shut down gracefully.
Most people think of these as something you’d need only if you lived where power cuts were a common occurrence. However, even in the middle of a busy city your power could fail for any number of reasons, from a simple blown fuse to roadworks problems, lightning strikes (they do happen), and so on. If the power fails your Mac will go down without warning. Not only will you not have a chance to save your work, the OS won’t have performed a graceful shutdown; you may need to run disk repair tools as a result. If you're unlucky your computer could suffer expensive hardware damage as well. Wherever you live, if you use computers, a UPS is well worth considering.
Another benefit you’ll get from a UPS device are ‘line conditioning’ features. Generally referred to as automatic voltage regulation, these tame fluctuations in your mains power. Although you would expect your incoming electricity supply to give you an unvarying 240v current (or whatever is standard for your part of the world), it will actually fluctuate from time to time. You may have noticed your lights dim for half a second once in a while; that’s a crude visual symptom of the effects of ‘dirty’, unregulated power. This can cause stress to sensitive electronic equipment. Although it is generally soaked up by the poswer supply units within your IT equipment, it will still take its toll on those components at least, and can lead to crashes and freezes. Automatic voltage regulation curcuits are designed to take such spikes and troughs in their stride and pass a tamed result on to connected equipment.
When choosing a UPS device, make sure that you pick one which will be able to handle the demands of everything you want protected. UPS suppliers will normally help you work out what level of device you need, but if not you can work it out yourself with some simple maths. Next to the power socket on Macs, PCs and virtually all other IT equipment you’ll find the item’s amps rating. Multiply that by the mains voltage and you’ve got the VA rating; volts x amps = VA. (VA is also commonly called watts, although an electrician will point out that there’s a difference between the two.) If necessary, divide the VA figure by the UPS device’s capacity and you’ll have the length of time its battery can maintain those items on its own; VA / capacity = uptime. If you prefer, a UPS capacity calculator can be found at CSGNetwork.com.
When looking through catalogues don’t go by a manufacturer’s quoted maximum battery running time; that will be calculated with the minimum load rather than a realistic one of the device under full load. Make sure you get a unit which has 25% or more VA capacity than your existing needs. This will ensure you get a bit more than the minimum amount of time when running from the battery, and it also gives you scope for using slightly higher-rated equipment in the future without risking the UPS failing to keep you running in a crisis.
Remember, having a UPS doesn’t mean you can keep working even if the mains power fails. These devices are meant to provide enough time to sort things out, not to let you carry on with your work as if nothing’s happened. Only use a UPS for items which really must be kept alive for a short time if the power fails. Anything which pulls a lot of power shouldn’t be connected via one of these unless absolutely necessary. Your monitor is a logical choice, as are any external hard drives. Other devices are less necessary; for example, scanners don’t need the UPS treatment. Laser printers will stress a UPS’s throughput quite heavily, especially when first turned on. Remember, if there’s a power failure your main concern should be in saving your work and shutting down gracefully, not in making a few prints. If you’d like to have your laser printer protected from fluctuations in mains power then by all means connect it to the surge-protection sockets. These flatten out power spikes, causing less stress to the electronics and providing protection against lighting strike pulses. Just don’t hook it up to the battery-backed sockets or you’ll shorten the life of the UPS itself.
When there’s a power failure your UPS device will start beeping to let you know that it, or rather your computer, is running on battery power. Most units will offer extra connections to your Mac or PC via USB or Ethernet, and can, in conjunction with bundled software, automate the process of shutting it down. This is ideal for unattended servers, but it can also be useful if you happen to be away from your Mac when the power fails. Some UPS devices come with Windows-only software and PC-specific serial connections, but there are utilities for OS X that can work with these, even if a USB-to-serial adaptor is used. Aside from this, any UPS hardware will work with Macs as well as PCs, as it simply provides temporary power when needed.
This article copied from www.thesmallest.com.
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