Raceway - Any channel designed for holding
wires, cables, or busbars, and, unless otherwise qualified in the
Rules of Code, the term includes conduit (rigid and flexible, metal
and nonmetallic), electrical metallic and nonmetallic tubing, underfloor
raceways, cellular floors, surface raceways, wireways, cable trays,
busways, and auxiliary gutters.
Radial Feed - One primary bushing per phase.
Radio-Influence Voltage (RIV) - A high frequency
voltage, generated by all sources of ionization current, that appears
at the terminals of electric power apparatus or on power circuits.
Ratio - A reference to either the turns ratio
or the voltage ratio of a transformer.
RE Conduit - see definition for Conduit.
Reactance - A component of impedance produced
by either inductance or capacitance in an ac circuit.
Reactor - A device for introducing inductive
reactance into a circuit for motor starting, operating transformers
in parallel, and controlling current.
Readily Accessible - Capable of being reached
quickly for operation, renewal, or inspection, without requiring
those to whom ready access is a requisite to climb over or remove
obstacles or to resort to portable ladders, chairs, etc.
Receptacle - One or more female contact devices,
on the same yoke, installed at an outlet for the connection of
one or more attachment plugs.
Single Receptacle - One female contact device, with no other
contact device on the same yoke, installed at an outlet for the
connection of one attachment plug.
Duplex Receptacle - Two female contact devices, on the same
yoke, installed at an outlet for the connection of two attachment
Split Receptacle - A duplex receptacle having terminals adapted
for connection to a grounded, 3-wire supply, eg, 120/240 V or
Recovery Voltage - The voltage potential established
across the open electrodes of an overcurrent protection device
after clearing the circuit at a current zero; a term used to designate
the voltage impressed by the circuit upon the interrupting device
after interruption of the current at or about the time of a natural
Recreational Vehicle - a structure designed to provide temporary
living accommodation for travel, vacation,
or recreational use and to be driven, towed, or transported. Except
for fifth-wheel trailers, it has an overall length
not exceeding 12.5 m and an overall width not exceeding 2.6 m,
where the width is the sum of the distances
from the vehicle centreline to the outermost projections on each
side. These dimensions exclude safety-related
equipment such as side safety and warning lights and entry and
exit handholds. Also excluded are water spray
suppression attachments, load-induced tire bulge, and equipment
used to secure cargo on a vehicle. These
excluded items are allowed to extend not more than 100 mm when
the vehicle is folded or stowed for transit.
For a fifth-wheel trailer the maximum overall length is 11.3 m
taken from the rear extremity to the front of the
main body, measured at the floorline. Such structures include travel
trailers, slide-in campers, camping trailers,
motor homes, and fifth-wheel trailers:
Camping Trailer - a recreational vehicle built
on its own chassis, having a rigid or canvas top and side
walls, that may be folded or otherwise stowed for transit and
that is designed to be towed behind a motor
Fifth-Wheel Trailer - a recreational vehicle
designed to be coupled to the towing vehicle by a fifthwheel-
type coupler, through which a substantial part of the trailer
weight is supported by the towing vehicle.
Motor home - a recreational vehicle that is self-propelled.
For purposes of applying the CAN/CSA-Z240
RV Series, this includes a van conversion containing at least
- plumbing fixture;
- fuel-burning appliance; or
- 120V electrical component.
Slide-in Camper - a recreational
vehicle designed to be loaded onto, and unloaded from, the bed
Travel Trailer - a recreational vehicle designed
to be towed behind a motor vehicle by means of a bumper
or frame hitch.
Recreational Vehicle Park - An area of land designed
to accommodate recreational vehicles and park model trailers.
Reduced Capacity Tap - Tap that is not designed
to deliver the rated capacity of the transformer.
Reference Current (Iref) - The reference current
is the peak value of the resistive component of a power frequency
current high enough to make the effects of stray capacitance of
the equipment negligible. This current level shall be specified
by the manufacturer.
Reference Voltage (Vref) - The lowest peak value
independent of polarity of power frequency voltage, divided by
the square root of 2, required to produce a resistive component
of current equal to the reference current of the equipment or element,
i.e., the reference voltage of a multi-unit arrester is the sum
of the reference voltages of the series units. The voltage level
shall be specified by the manufacturer.
Relocatable Structure - A factory-built unit
for use without a permanent foundation.
Remote Control Circuit - Any electrical circuit
which controls any other circuit through a relay or an equivalent
Repellent used as a Suffix (such as moisture-repellent) -
A material constructed, treated, or surfaced so that liquid will
tend to run off, and cannot readily penetrate the surface.
Residential Occupancy - The occupancy or use
of a building or part thereof by persons for whom sleeping accommodation
is provided but who are not harboured or detained to receive medical
care or treatment or are not involuntarily detained.
Resistant used as a Suffix (such as absorption-resistant,
moisture-resistant, etc) - Material constructed, protected,
or treated so that it will not be injured readily when subjected
to the specific material or condition.
Resistor - Any device of material that limits
the flow of current when voltage is applied.
Resonance - A state in which the capacitance
and the inductance values in a circuit are equal (net reactance
is equal to zero) and the only quantity left is resistance.
Resonant Frequency - Frequency at which the voltage
and the current at the input terminals are in phase. Reactance
is equal to zero.
RMS Line Current - The square root of the average
of the squares of all the instantaneous current amplitudes occurring
during one cycle.
Routine Tests - Test made by the manufacturer
on every device or representative samples, or on parts or materials,
as required, to verify that the product meets the design specifications.