WHAT IS A POWER CONDITIONER?
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.
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