UPS vs. Power Conditioning
At the heart of most computer and telecommunications hardware is a Switch Mode Power Supply (SMPS).
The SMPS converts the ac (alternating current) mains supply into the levels of dc (direct current) required by the logic circuits.
It is designed to operate on a normal mains supply. Some may have the ability to cope with a limited range of mains fluctuations. Designed to a minimum cost base in a highly competitive market they are the first weak point in an Information and Communications Technology (ICT) application. A fluctuating mains supply causes 'wear and tear’ on the SMPS’ components. This leads to operating conditions where it cannot perform, crashes or eventually fails.
The second weak point is the internal processing hardware. This requires 'tight’ levels of dc to operate effectively and uses internal memory to store data prior to saving to some type of storage device e.g. a hard disk, tape back up, optical disk or flash ROM.
When mains problems cause the SMPS to operate erratically or fail, information processing and operation are affected. Information may be lost, the system may hang, files can be corrupted and the hardware malfunction or be permanently damaged.
The ICT user is faced with hardware replacement, file recreation and downtime costs. The hardware supplier incurs charges to write off against maintenance income.
Common mains power problems
When mains is present the most common types of power problems are spikes electrical noise sags and surges.
Spikes and electrical noise are associated with the use of modern office equipment heavy industrial machinery and nearby lightning strikes.
Sags and surges can be less common unless there is a significant decrease in the capacity of the utility companies to provide electrical power or the site is in a rural location.
Mains failures can be less damaging than spikes electrical noise sags and surges. However they can cause the maximum instantaneous disruption.
For more info on power problems read this pdf 'Power Quality Myths and Magic'
The natural reaction to mains power problems is to install some form of UPS protection.
Types of UPS read this pdf 'Types of UPS explained'
This may not be the most suitable approach. Almost all cheap UPS provide little or NO PROTECTION against over 98% of mains power problems, and there more expensive cousins are generally more expensive and less reliable than the alternatives.
Advance tackles power problems by considering the application, the degree of mains pollution present and the need if any to work during complete mains failure.
How polluted is the mains supply?
For sites where the mains supply is heavily polluted by spikes and electrical noise the load may need some form of Galvanic Isolation transformer.
This forms a physical barrier between the input and load. It is the most effective protection against spikes and electrical noise.
Can the load can stand a break in the mains supply?
Where the application is unaffected by a mains failure (or the budget is not available for a UPS) a power conditioner becomes the preferred solution. Advance Power Conditioners are transformer based and provide Galvanic Isolation. Any mains borne spikes and electrical noise are routed directly to earth. The protected load receives clean computer-grade power.
Types of power conditioner
1. AIT series power conditioners (Ultra Isolation Transformers) provide protection from spikes and electrical noise. They are a 'fit and forget’ low-cost and maintenance free product recommended for applications such as EPoS and small PBX applications.
2. AGT series power conditioners (Constant Voltage Transformer - CVT) provide the benefits of an AIT series power conditioner coupled with the ability to provide voltage stabilisation over a wide input voltage window. They are recommended for all SMPS and other applications which cannot cope with a widely fluctuating mains supply.
3. AVS series (Automatic Voltage Stabilisers) provide a low cost alternative to CVTs where the load is inductive for example refrigerators and air conditioning.
Does the load have to be kept running at all times?
In such instances a UPS must be installed. It should have a sufficiently wide input voltage window to cope with sags and surges in the mains supply.
How long must it run for?
The standard UPS runtime is typically 5-10 minutes. Some UPS types can have extended runtime packs (and chargers) fitted.