Powervar's ABCs of Power Conditioning

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It seems like almost every power protection device that’s sold today claims to be a power conditioner. But what really makes a power conditioner? The answer to that question depends largely on determining the power quality needs of the electronic load.

A system with a linear type power supply will frequently already have an isolation transformer but may be sensitive to voltage fluctuations. These systems will probably need some type of surge diverter and maybe a voltage regulator, too.

Most modern electronic systems, however, have switched mode power supplies (SMPS). This type of power supply technology is largely immune to changes in power line voltage but in the process of making the power supply smaller, more efficient, and cheaper, the isolation transformer has been eliminated from the design. Systems with a switched mode power supply will require, at a minimum, a surge diverter, a noise filter, and an isolation transformer.

Meanwhile, any system in which data is held, edited, or manipulated in some way in volatile memory may need the protection of a battery backup system or UPS to ensure that data can be saved and the system properly shutdown in the event of a power outage.

POWERVAR originated the concept of The ABCs of Power Conditioning to simplify the process of understanding power protection and to help customers determine which power conditioning elements are parts of the power protection products they are using or evaluating. All of POWERVAR’s product model numbers start with one or more of the ABCs. For example, our model ABC201-11 tells you that the product is a power conditioner containing a surge diverter, an isolation transformer, and a noise filter. Our model ABCE500-11contains these same elements in addition to a battery backup - in other words, it’s a fully power conditioned uninterruptible source of power. We’ve always used the ABCs so that customers may clearly see which protection elements are found in the solutions we manufacture.

We invite you to browse the topics in this section to learn more about power quality and electrical power in general.

• [A] The Surge Diverter — This is the most commonly-used "solution" because it is the least expensive and best-recognized power protection device. Surge diverters can only protect from transient voltages that exceed about 250 volts. When these large voltages occur, surge diverters clip the excess voltage and send it to ground where it is converted into a common mode power disturbance that can disrupt microprocessor function. Because transient voltages smaller than 250 volts slip by the surge diverter, the computer is exposed to substantial degrading energy.
• [B] The Low impedance Isolation Transformer — This component provides an inductive cushion for the load and enhances the operation of surge diverters and noise filters by re-establishing a vital neutral-to-ground bond permitted by National Electrical Code. The bond prevents the formation of common mode voltages created when surge diverters and noise filters shunt power disturbances to safety ground.
• [C] The Power Line Filter — Power line noise filters address the low-amplitude, high-frequency noise disturbances that are missed by the surge diverter. Quality noise filters are often left out of many power protection devices. Like surge diverters, they operate by shunting noise to satefy ground.
• [D] The Voltage Regulator — Voltage regulators are responsible for keeping power line voltage within specified upper and lower limits. Computers today use switch mode power supplies (SMPS) which do not require tightly regulated voltage. This is fortunate since most voltage regulation technology is obsolete, generates noise, and is unsuitable for use with today's systems.
• [E] The Battery Backup — Computer systems can't function if there is an interruption to their supply of electrical power. In the event of a power outage, the battery backup converts reserve DC energy (stored in batteries) into AC power for the computer load. The most common type of battery backup is the standby UPS, which switches to batteries when power is lost. More expensive on-line UPS systems are also available to provide constant AC to DC to AC power conversion. Many on-line systems can also regulate voltage. Few UPS systems, regardless of the design, provide good common mode protection because they do not include an output isolation transformer.
• [F] The Frequency Regulator — Frequency regulators ensure that the power line frequency stays at a constant 60Hz (50Hz in Europe and much of the rest of the world). In most well-developed countries, frequency regulation is not required since the power-generating utilities provide very frequency-stable electrical power. This is not always true in developing or "emerging" countries, however. Where frequency regulation is required, an on-line UPS or inverter is the only way of providing AC power with tightly regulated line frequency.
• [G] Ground Guard — Ground Guard is a POWERVAR designed and patented technique for the elimination of ground loops in a networked system. When computers are connected together throughout a building, the natural variations in electrical ground impedance cause noise currents to flow in the loops created by the data cable's signal-grounding conductors. Ground Guard prevents the formation of these ground loops and is a necessity when equipment is networked together.