
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°C (100°F), or a flammable liquid whose temperature is above
its flash point, or a Class II combustible liquid that has a
vapor pressure not exceeding 276 kPa (40 psia) at 38°C (100°F)
and whose temperature is above its flash point.


Volt 
The unit of voltage or potential difference.
The unit of electromotive force, electrical pressure, or
difference of potential. Represented by E or V.


Volt Amperes 
The
product of the voltage across a circuit and the current in the
circuit. Expressed in VA.


Voltage 
Electrical pressure, the force which causes
current to flow through a conductor.


Voltage (of a circuit) 
The greatest rootmeansquare (rms) (effective)
difference of potential between any two conductors of the
circuit concerned.


Voltage Drop 
The loss of voltage between the input to a
device and the output from a device due to the internal
impedance or resistance of the device. In all electrical
systems, the conductors should be sized so that the voltage drop
never exceeds 3% for power, heating, and lighting loads or
combinations of these. Furthermore, the maximum total voltage
drop for conductors for feeders and branch circuits combined
should never exceed 5%.


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.


Voltage, Nominal 
A nominal value assigned to a circuit or system
for the purpose of conveniently designating its voltage class
(e.g., 120/240 volts, 480Y/277 volts, 600 volts). The actual
voltage at which a circuit operates can vary from the nominal
within a range that permits satisfactory operation of equipment.


Voltage
Ratio 
The
voltage ratio of a transformer is the ratio of the r.m.s.
primary terminal voltage to the r.m.s. secondary current, under
specified conditions of load.
