Circuit breaker cont'd - hdbk109220040242

DOE-HDBK-1092-2004

Motor-circuit switch--A switch, rated in horsepower, capable of interrupting the maximum

operating overload current of a motor of the same horsepower rating as the switch at the

rated voltage.

Switching devices--(Over 600 volts, nominal.) Devices designed to close and/or open one or

more electric circuits. Included in this category are circuit breakers, cutouts, disconnecting (or

isolating) switches, disconnecting means, interrupter switches, and oil (filled) cutouts.

Transportable X-ray--X-ray equipment installed in a vehicle or that may readily be

disassembled for transport in a vehicle.

Utilization equipment--Utilization equipment means equipment which utilizes electric energy

for mechanical, chemical, heating, lighting, or similar useful purpose.

Utilization system--A utilization system is a system which provides electric power and light for

employee workplaces, and includes the premises wiring system and utilization equipment.

Ventilated--Provided with a means to permit circulation of air sufficient to remove an excess of

heat, fumes, or vapors.

Volatile flammable liquid--A flammable liquid having a flash point below 38 degrees C (100

degrees F) or whose temperature is above its flash point.

Voltage (of a circuit)--The greatest root-mean-square (effective) difference of potential between

any two conductors of the circuit concerned.

Voltage, nominal--A nominal value assigned to a circuit or system for the purpose of

conveniently designating its voltage class (as 120/240,480Y/277, 600, etc.). The actual voltage

at which a circuit operates can vary from the nominal within a range that permits satisfactory

operation of equipment.

Voltage to ground--For grounded circuits, the voltage between the given conductor and that

point or conductor of the circuit that is grounded; for ungrounded circuits, the greatest voltage

between the given conductor and any other conductor of the circuit.

Watertight--So constructed that moisture will not enter the enclosure.

Weatherproof--So constructed or protected that exposure to the weather will not interfere with

successful operation. Rainproof, raintight, or watertight equipment can fulfill the requirements for

weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or

temperature extremes, are not a factor.

Wet location--See "Location."

Wireways--Wireways are sheet-metal troughs with hinged or removable covers for housing and

protecting electric wires and cable and in which conductors are laid in place after the wireway

has been installed as a complete system.

B-16