Electrical general

Electricity is generally described in terms of various numbers and equations, and some definitions are in order:

Voltage (volts):
High voltage: Variably defined as >600 volts or >1000 volts
Low voltage: Variably defined as <600 volts or <1000 volts

Amperage (amps):

Resistance:

Current:
Alternating current (AC): most common in US power lines; low voltage AC current typically regulated at 60 Hz (60 oscillations per second).
Direct current (DC):

Ground:

Electrocution: any electrical injury; widely used to describe a fatal event, but by definition death is not required

Three basic elements are required for an electrocution to occur: a charged electrical source, a current pathway through the subject/tissue to be injured, and a ground. These things constitute a completed circuit. The absence of one of these means there is no electrocution; this is why birds can sit happily on electrically charged wires, as there is no ground to complete the circuit.

High voltage power lines carry on the order of 100 kV or more in the US, which is stepped down at substations and transformers to less than 10,000 volts. This is typically down to approximately 7650 volts in residential power lines, and again down to 120-240 volts at the final street-side/utility pole transformer prior to entering an individual residence (or approximately 480 volts for industrial use). By comparison, cloud to ground lightning bolts have been estimated at up to approximately 1 billion volts, up to approximately 200,000 amps, and travel through air up to about 10 miles in total. Typical capital punishment electric chairs utilize 2000-2200 volts AC at 7-12 amps.

Household/residential electricity is typically 120 volts AC, with 220-240 volts AC used for dryers, ranges, hot tubs, and some power tools.
Created by kcshaw. Last Modification: Friday 10 of July, 2009 08:11:26 CDT by kcshaw.

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