Alternating current (AC) is utility-supplied power accessed through power outlets.
An amp , a unit of measure for electrical current, refers to the amount of electricity per second flowing through a wire.
A blackout , or power failure, is a complete loss of AC line voltage that can last for several seconds or go on for several days.
A brownout , or undervoltage, is a partial loss of AC line voltage, usually below 103V.
EMI/RFI Electrical Interference refers to unwanted signals common in noisy electrical environments.
A ground is the third prong on any wall receptacle connected to safety ground, where energy is discharged in emergency conditions.
Hertz (Hz) is the frequency of alternating cycles per second in an AC waveform. North American utility power is provided at 60Hz. In Europe and most of the rest of the world, utility power is provided at 50Hz.
Joule ratings measure a surge suppressor's ability to handle surges: more joules mean more protection.
KVA refers to one thousand volt amps. 1 kVA = 1000VA.
Overvoltage is a partial increase of AC line voltage, usually over 132V.
A surge , or spike, is a momentary rise in line voltage that can be of the magnitude of tens to thousands of volts.
A UPS , or Uninterruptible Power Supply, device provides continuous acceptable power to its dependent loads no matter what the power status is on the commercial utility's power lines.
VA (volt amps) is the amount of theoretical current used by a particular load. VA = volts x amps. For example, if a piece of 120V equipment is rated at 3 amps, its VA rating is 360 (120 x 3). Most UPS systems are rated in VA. Actual wattage is typically 60 to 70 percent of this figure.
A volt is a unit of measure for voltage, which is electrical pressure that forces current to flow in a conductor, such as a wire.
Watt is a unit of measure for true power consumption.