UPS - Battery Backup Power

1 - The primary function of any UPS system is to provide a constant source of clean, conditioned, AC power to the protected device.

2 - A good UPS unit will also filter and protect every connection point between the outside world and your computer system. (power line, cable connection, telephone / fax line, etc.)

3 - Provide adequate run time which either: (A) Exceeds the length of the power event. (B) Allows enough time to safely shut down the system, or (C) Automates a safe, unattended, shutdown process in the event of a lengthy power outage.

4 - Sacrifice itself in the event of a direct lightning strike, thus saving the protected system.

When it comes to power protection bigger really is better. Overkill is a term that has no meaning in this instance. You should get the most protection your budget will allow.

Plain and simple: You can never have too much protection. Too many backup watts, too many power outlets, too tight of voltage regulation, etc.

MINIMUM REQUIREMENTS:

Every electrical appliance has a label displaying its power consumption (usually near the power cord). This information will also be listed in the specifications section of the owners manual. Find this information and make note of the wattage used by each component. Add them all together. The total amount will yield the bare minimum wattage your UPS will need to provide in the event of a power event.

UPS Wattage > Load Wattage Total

The greater your UPS rating exceeds this minimum requirement, the longer your useful runtime will be. Also... Exceeding the recommended minimum UPS wattage requirement allows for system upgrades and heavier system loads.

TIP: UPS protection is not just for computers. Home Theater Systems, Aquariums, Freezers, nearly anything that requires constant, clean AC power...

Power, Apparent Power & Power Factor (Comparing Apples to Oranges?)

The unit of measurement for electrical power is the Watt [W]. Named after Scottish inventor James Watt (1736 - 1819) it is calculated by multiplying the [voltage supplied across a load, measured in volts V] x [the current flowing through that load, measured in amperes A] with the load [offering resistance measured in ohms R] being the device drawing the power from the power source. So, mathematically... W=VxA or W=(AxA)/R

But it's not that simple. This calculation is accurate only for purely resistive loads. [R]

With AC circuits the total load is both resistive [R] and reactive [Xc, Xl]. This property is referred to as impedance [Z].

Because load impedance interacts (reacts) with the AC power, the actual power consumed will not be the same as our simple Volts x Amps calculation would indicate. This difference can be expressed as the ratio: W/VA This ratio is known as the power factor of the device or circuit. Power factor has a range from 0 to 1.

Manufacturers of consumer electronics typically don't list the power factor specification of their products, so we are left to approximate this value.

In the technical community 0.6 is accepted as the approximate power factor of the typical desktop computer, yielding an equation : 0.6 = W/VA

As a general guide, we can determine our UPS VA rating needed by using this calculation:

UPS VA Rating >= Load Watts Total / 0.6

This calculation may not be accurate in every situation. It represents an approximation, and should be considered as such.

In English: Your UPS VA Rating should equal or exceed: your load wattage total (calculated from the specification labels on your equipment) divided by 0.6

EXAMPLE:

If Joe adds up all of his system power consumption label information and calculates a total of 700 Watts, then Joe needs a UPS with a rating of 1166VA or greater. (700 / 0.6 = 1166) Joe buys his UPS (here of course) rated at 1500VA. Joe is Happy :) His computer is protected with room to grow!

Watts / 0.6 = minimum VA Rating Approximation
(Remember, this is a starting point. The greater your UPS exceeds your minimum requirement the better!)

I have over 2 years of hands on experience working on computer power supplies and battery backup power systems. Performing trouble shooting and repair work (to the component level) on power supplies and battery backup units for use with commercial/corporate strength IBM servers.

But, I also signed a confidentiality / non-disclosure agreement! So I won't be telling you any more about this project. (code named: IBM MAX)

I can read (and understand) electronic schematics. Then, using sophisticated test equipment, track down, remove and replace, faulty components on a circuit board.

I know my way around a high tech electronics lab. I also understand the "hows & whys" of computer power supplies and UPS battery backup systems.

I use UPS units on every system I own.
I always have, I always will.

You should too...

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