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Juice Goose

7320 Ashcroft
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Houston, TX 77081
United States
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What Is A Power Conditioner?
Posted on Tuesday, December 6, 2016


At Juice Goose, we consider “power conditioner” to be a general term that refers to anything that produces a systematic change in the condition of AC current. Think “air  conditioner”, a general term for a machine that cools, filters and circulates. Interest lies in several specific functions – any or all of which may be present in a particular power conditioner.

VOLTAGE REGULATION - US electric utility power (commercial and  residential single phase) is standardized at 120 volts.  Electric utilities aim to keep most customers supplied between 114 and 126.  However, long or short term variations in the peak or RMS voltage do occur. Causes include distance from a transformer and power consumption relative to the capacity of the power grid.

When the RMS voltage exceeds the nominal correct voltage by a certain margin, the event may be called a "swell". A "dip", "sag" or “brown out” (long duration) is a low voltage event which is more common than high voltage. A regulator can accept this voltage variance within a limited range and produce correct voltage output using one of  a few technologies. Some UPSs (referred to as line interactive or on line) provide voltage regulation. But that is not their primary function. (See below.)   

LINE FILTRATION – Utility power current and voltage in the US alternates at a frequency of 60 times per second (60 Hz). However, other power impulses of much higher frequencies can ride on the power line. Sources of these impulses include electric motors, neon lights, light dimmers, switching power supplies and radio broadcasts. This noise can travel between line and neutral (normal mode) or line and ground (common mode) and may be converted to actual audible or visible noise in a sound or video component. A variety of inductor and capacitor circuit designs can clean up this high frequency noise and leave mostly the 60 Hz. When considering such a filter device check that the model addresses both normal mode and common mode noise. The manufacturer should produce performance statistics for both. 

SURGE AND SPIKE PROTECTION - These terms refer to very short duration, high energy events where voltage can rise to many times the specified 120 VAC level and then normalize. Those terms are  commonly used interchangeably. The most expected source of voltage surges and spikes is lightning. Other sources include industrial machinery turning on an off and power line balancing by the utility.

These events can occur between line and neutral (normal mode) as well as between line or neutral and ground (common mode). Catastrophic damage most often occurs as normal mode. However, common mode interference is much more common. While less obvious, common mode interference can disrupt digital processors using ground as reference for logic voltage. Be sure any surge or spike protection device you are considering provides both normal mode and common mode protection.

BATTERY BACK UP - It is a misconception that a battery back up (“UPS”) is the best form of power conditioner available. In fact, the main function of a UPS is to provide a brief period of power continuation during a utility power failure. Standard battery run times are around 5 to 10 minutes. The smaller the load the longer the run time.  A true on-line UPS powers connected equipment off the battery 100% of the time and uses utility power only to charge the UPS battery. These, “double conversion” models provide complete isolation from incoming utility power. Line interactive or stand-by UPS designs provide battery support only when line voltage drops to between 100 and 110  volts.  The level of power filtration and protection provided by these UPSs varies between models.

When specifying or  purchasing a “power conditioner” consider the main functions you want it to perform and look for detailed performance data related to those functions.