•−• ••−• −•−• •− ••−• • RF Cafe in Morse Code: Hear It
Hazardous Voltage Levels
High voltage. Low voltage. We hear the term used often, but it would be good to have a definitive listing of what voltage levels qualify for which levels. The table below lists some typical names and what the corresponding voltage levels. The video clip at the left appeared as a Cool Pic on RF Cafe a year or so ago, and the one on the right is a recently found one. Both are awesome.
Considered "safe" for touching (although never recommended). Protected to "guarantee" voltage will never rise above these levels, even under a fault condition. Double insulated.
Extra-Low1
≤42.2 Vac pk, ≤60 Vdc
Non-touchable, but considered safe due to insulation from hazardous voltages.
Low2
≤1 kVac
Considered hazardous. These level are found in common residential and commercial equipment installations.
Medium3
>1 kVac to 100 kVac
Very hazardous. Residential and small commercial transformers, both on poles and on the ground.
High3
≥100 kVac to ≤230 kVac
Very hazardous. Found in transmission grid systems including substations.
Extra-High4
>230 kVac to ≤800 kVac
Extremely hazardous, even at a distance. Transmission systems between substations and power generation.
Ultra-High4
>800 kVac to 2 MVac
Extremely hazardous, even at a great distance. Transmission systems between substations and power generation.
References:
1: IEC 60950-1
2: NEC-NFPA 70 low voltage = 600 V, ANSI/IEEE low voltage = 1 kVac, EU's Low Voltage Directive = 50 V to 1 kVac & 75 to 1.5 kVdc
3: ANSI C84.1 & IEEE 100
4: IEEE 1312 & IEEE 100
Note: Numbers shown are NOT total page views; they are unique IP addresses for each 24-hour period (i.e., unique visitors). Typical page view counts are at least twice the reported unique visitor number.
RF Cafe Erie, PA (814) 833-1967
A Disruptive Web Presence™ GPS Coordinates: N 42°04.577', W 080°11.757'
