Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-155 - Safety standards for construction work › Part I - ELECTRICAL › Section 296-155-462 - Definitions applicable to this part

Current through Register Vol. 24-14, July 15, 2024
The definitions given in this section apply to the terms used
				  in Part I. The definitions given here for "approved" and "qualified person"
				  apply, instead of the definitions given in WAC
				  296-155-012, to the use of these
				  terms in Part I.
Acceptable.
An installation or equipment is
				  acceptable to the director, and approved within the meaning of this Part
				  I:
* If it is accepted, certified, listed, labeled, or
				  otherwise determined to be safe by a qualified testing laboratory capable of
				  determining the suitability of materials and equipment for installation and use
				  in accordance with this standard; or
* With respect to an installation or equipment of a kind
				  which no qualified testing laboratory accepts, certifies, lists, labels, or
				  determines to be safe, if it is inspected or tested by another state agency, or
				  by a federal, municipal, or other local authority responsible for enforcing
				  occupational safety provisions of the National Electrical Code, and found in
				  compliance with those provisions; or
* With respect to custom-made equipment or related
				  installations which are designed, fabricated for, and intended for use by a
				  particular customer, if it is determined to be safe for its intended use by its
				  manufacturer on the basis of test data which you keep and make available for
				  inspection to the director and his/her authorized representatives.
Accepted.
An installation is "accepted" if it
				  has been inspected and found to be safe by a qualified testing
				  laboratory.
Accessible.
(As applied to wiring methods.)
				  Capable of being removed or exposed without damaging the building structure or
				  finish, or not permanently closed in by the structure or finish of the
				  building. (See "concealed" and "exposed.")
Accessible.
(As applied to equipment.) Admitting
				  close approach; not guarded by locked doors, elevation, or other effective
				  means. (See "readily accessible.")
Ampacity.
The current in amperes a conductor can
				  carry continuously under the conditions of use without exceeding its
				  temperature rating.
Appliances.
Utilization equipment, generally
				  other than industrial, normally built in standardized sizes or types, which is
				  installed or connected as a unit to perform one or more functions.
Approved.
Approved by the director of the
				  department of labor and industries or his/her authorized representative:
				  Provided, however, That should a provision of this chapter state that approval
				  by an agency or organization other than the department of labor and industries
				  is required, such as Underwriters' Laboratories, the Bureau of Mines, or Mine
				  Safety and Health Administration (MSHA) and the National Institute for
				  Occupational Safety and Health (NIOSH) the provisions of WAC
				  296-155-006 must apply.
Askarel.
A generic term for a group of
				  nonflammable synthetic chlorinated hydrocarbons used as electrical insulating
				  media. Askarels of various compositional types are used. Under arcing
				  conditions the gases produced, while consisting predominantly of noncombustible
				  hydrogen chloride, can include varying amounts of combustible gases depending
				  upon the askarel type.
Attachment plug (plug cap) (cap).
A device
				  which, by insertion in a receptacle, establishes connection between the
				  conductors of the attached flexible cord and the conductors connected
				  permanently to the receptacle.
Automatic.
Self-acting, operating by its own
				  mechanism when actuated by some impersonal influence, as for example, a change
				  in current strength, pressure, temperature, or mechanical configuration.
Bare conductor.
See "conductor."
Bonding.
The permanent joining of metallic parts
				  to form an electrically conductive path which will assure electrical continuity
				  and the capacity to conduct safely any current likely to be imposed.
Bonding jumper.
A reliable conductor to assure
				  the required electrical conductivity between metal parts required to be
				  electrically connected.
Branch circuits.
That portion of a wiring system
				  extending beyond the final overcurrent device protecting the circuit. (A device
				  not approved for branch circuit protection, such as thermal cutout or motor
				  overload protective device, is not considered as the overcurrent device
				  protecting the circuit.)
Building.
A structure which stands alone or
				  which is cut off from adjoining structures by fire walls with all openings
				  therein protected by approved fire doors.
Cabinet.
An enclosure designed either for
				  surface or flush mounting, and provided with a frame, mat, or trim in which a
				  swinging door or doors are or may be hung.
Certified.
Equipment is "certified" if
				  it:
* Has been tested and found by a qualified testing
				  laboratory to meet applicable test standards or to be safe for use in a
				  specified manner; and
* Is of a kind whose production is periodically inspected by
				  a qualified testing laboratory. Certified equipment must bear a label, tag, or
				  other record of certification.
Circuit breaker.
*
(600 volts nominal, or less.)
A device
				  designed to open and close a circuit by nonautomatic means and to open the
				  circuit automatically on a predetermined overcurrent without injury to itself
				  when properly applied within its rating.
*
(Over 600 volts, nominal.)
A switching device
				  capable of making, carrying, and breaking currents under normal circuit
				  conditions, and also making, carrying for a specified time, and breaking
				  currents under specified abnormal circuit conditions, such as those of short
				  circuit.
Class I locations.
Class I locations are those
				  in which flammable gases or vapors are or may be present in the air in
				  quantities sufficient to produce explosive or ignitible mixtures. Class I
				  locations include the following:
*
Class I, Division 1.
A Class I, Division 1
				  location is a location:
- In which ignitible concentrations of flammable gases or
				  vapors may exist under normal operating conditions; or
- In which ignitible concentrations of such gases or vapors
				  may exist frequently because of repair or maintenance operations or because of
				  leakage; or
- In which breakdown or faulty operation of equipment or
				  processes might release ignitible concentrations of flammable gases or vapors,
				  and might also cause simultaneous failure of electric equipment.
Note:
This classification usually includes
						  locations where volatile flammable liquids or liquefied flammable gases are
						  transferred from one container to another; interiors of spray booths and areas
						  in the vicinity of spraying and painting operations where volatile flammable
						  solvents are used; locations containing open tanks or vats of volatile
						  flammable liquids; drying rooms or compartments for the evaporation of
						  flammable solvents; inadequately ventilated pump rooms for flammable gas or for
						  volatile flammable liquids; and all other locations where ignitible
						  concentrations of flammable vapors or gases are likely to occur in the course
						  of normal operations.
*
Class I, Division 2.
A Class I, Division 2
				  location is a location:
- In which volatile flammable liquids or flammable gases are
				  handled, processed, or used, but in which the hazardous liquids, vapors, or
				  gases will normally be confined within closed containers or closed systems from
				  which they can escape only in case of accidental rupture or breakdown of such
				  containers or systems, or in case of abnormal operation of equipment; or
- In which ignitible concentrations of gases or vapors are
				  normally prevented by positive mechanical ventilation, and which might become
				  hazardous through failure or abnormal operations of the ventilating equipment;
				  or
- That is adjacent to a Class I, Division 1 location, and to
				  which ignitible concentrations of gases or vapors might occasionally be
				  communicated unless such communication is prevented by adequate
				  positive-pressure ventilation from a source of clean air, and effective
				  safeguards against ventilation failure are provided.
Note:
This classification usually includes
						  locations where volatile flammable liquids or flammable gases or vapors are
						  used, but which would become hazardous only in case of an accident or of some
						  unusual operating condition. The quantity of flammable material that might
						  escape in case of accident, the adequacy of ventilating equipment, the total
						  area involved, and the record of the industry or business with respect to
						  explosions or fires are all factors that merit consideration in determining the
						  classification and extent of each location.
Piping without valves, checks, meters, and similar devices
				  would not ordinarily introduce a hazardous condition even though used for
				  flammable liquids or gases. Locations used for the storage of flammable liquids
				  or of liquefied or compressed gases in sealed containers would not normally be
				  considered hazardous unless also subject to other hazardous conditions.
Electrical conduits and their associated enclosures separated
				  from process fluids by a single seal or barrier are classed as a Division 2
				  location if the outside of the conduit and enclosures is a nonhazardous
				  location.
Class II locations.
Class II locations are those
				  that are hazardous because of the presence of combustible dust. Class II
				  locations include the following:
*
Class II, Division 1.
A Class II, Division 1
				  location is a location:
- In which combustible dust is or may be in suspension in
				  the air under normal operating conditions, in quantities sufficient to produce
				  explosive or ignitible mixtures; or
- Where mechanical failure or abnormal operation of
				  machinery or equipment might cause such explosive or ignitible mixtures to be
				  produced, and might also provide a source of ignition through simultaneous
				  failure of electric equipment, operation of protection devices, or from other
				  causes; or
- In which combustible dusts of an electrically conductive
				  nature may be present.
Note:
Combustible dusts which are electrically
						  nonconductive include dusts produced in the handling and processing of grain
						  and grain products, pulverized sugar and cocoa, dried egg and milk powders,
						  pulverized spices, starch and pastes, potato and woodflour, oil meal from beans
						  and seed, dried hay, and other organic materials which may produce combustible
						  dusts when processed or handled. Dusts containing magnesium or aluminum are
						  particularly hazardous and the use of extreme caution is necessary to avoid
						  ignition and explosion.
*
Class II, Division 2.
A Class II, Division 2
				  location is a location in which:
- Combustible dust will not normally be in suspension in the
				  air in quantities sufficient to produce explosive or ignitible mixtures, and
				  dust accumulations are normally insufficient to interfere with the normal
				  operation of electrical equipment or other apparatus; or
- Dust may be in suspension in the air as a result of
				  infrequent malfunctioning of handling or processing equipment, and dust
				  accumulations resulting therefrom may be ignitible by abnormal operation or
				  failure of electrical equipment or other apparatus.
Note:
This classification includes locations
						  where dangerous concentrations of suspended dust would not be likely but where
						  dust accumulations might form on or in the vicinity of electric equipment.
						  These areas may contain equipment from which appreciable quantities of dust
						  would escape under abnormal operating conditions or be adjacent to a Class II,
						  Division 1 location, as described above, into which an explosive or ignitible
						  concentration of dust may be put into suspension under abnormal operating
						  conditions.
Class III locations.
Class III locations are
				  those that are hazardous because of the presence of easily ignitible fibers or
				  flyings but in which such fibers or flyings are not likely to be in suspension
				  in the air in quantities sufficient to produce ignitible mixtures. Class III
				  locations include the following:
*
Class III, Division 1.
A Class III, Division
				  1 location is a location in which easily ignitible fibers or materials
				  producing combustible flyings are handled, manufactured, or used.
Note:
Easily ignitible fibers and flyings include
						  rayon, cotton (including cotton linters and cotton waste), sisal or henequen,
						  istle, jute, hemp, tow, cocoa fiber, oakum, baled waste kapok, Spanish moss,
						  excelsior, sawdust, woodchips, and other material of similar nature.
*
Class III, Division 2.
A Class III, Division
				  2 location is a location in which easily ignitible fibers are stored or
				  handled, except in process of manufacture. Collec-
tor ring. A collector ring is an assembly of slip rings for
				  transferring electrical energy from a stationary to a rotating member.
Collector ring.
A collector ring is an assembly
				  of slip rings for transferring electrical energy from a stationary to a
				  rotating member.
Concealed.
Rendered inaccessible by the
				  structure or finish of the building. Wires in concealed raceways are considered
				  concealed, even though they may become accessible by withdrawing them. See
				  "accessible. (As applied to wiring methods.)"
Conductor.
*
Bare.
A conductor having no covering or
				  electrical insulation whatsoever.
*
Covered.
A conductor encased within material
				  of composition or thickness that is not recognized as electrical
				  insulation.
*
Insulated.
A conductor encased within
				  material of composition and thickness that is recognized as electrical
				  insulation.
Controller.
A device or group of devices that
				  serves to govern, in some predetermined manner, the electric power delivered to
				  the apparatus to which it is connected.
Covered conductor.
See "conductor."
Cutout.
(Over 600 volts, nominal.)
An assembly of a fuse support with either a fuseholder, fuse carrier, or
				  disconnecting blade. The fuseholder or fuse carrier may include a conducting
				  element (fuse link), or may act as the disconnecting blade by the inclusion of
				  a nonfusible member.
Cutout box.
An enclosure designed for surface
				  mounting and having swinging doors or covers secured directly to and
				  telescoping with the walls of the box proper. (See "cabinet.")
Damp location.
See "location."
Dead front.
Without live parts exposed to a
				  person on the operating side of the equipment.
Device.
A unit of an electrical system which is
				  intended to carry but not utilize electric energy.
Disconnecting means.
A device, or group of
				  devices, or other means by which the conductors of a circuit can be
				  disconnected from their source of supply.
Disconnecting (or isolating) switch.
(Over
				  600 volts, nominal.)
A mechanical switching device used for isolating a
				  circuit or equipment from a source of power.
Dry location.
See "location."
Enclosed.
Surrounded by a case, housing, fence
				  or walls which will prevent persons from accidentally contacting energized
				  parts.
Enclosure.
The case or housing of apparatus, or
				  the fence or walls surrounding an installation to prevent personnel from
				  accidentally contacting energized parts, or to protect the equipment from
				  physical damage.
Equipment.
A general term including material,
				  fittings, devices, appliances, fixtures, apparatus, and the like, used as a
				  part of, or in connection with, an electrical installation.
Equipment grounding conductor.
See "grounding
				  conductor, equipment."
Explosion-proof apparatus.
Apparatus enclosed in
				  a case that is capable of withstanding an explosion of a specified gas or vapor
				  which may occur within it and of preventing the ignition of a specified gas or
				  vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or
				  vapor within, and which operates at such an external temperature that it will
				  not ignite a surrounding flammable atmosphere.
Exposed. (As applied to live parts.)
Capable of
				  being inadvertently touched or approached nearer than a safe distance by a
				  person. It is applied to parts not suitably guarded, isolated, or insulated.
				  (See "accessible" and "concealed.")
Exposed. (As applied to wiring meth-ods.)
On or
				  attached to the surface or behind panels designed to allow access. See
				  "accessible. (As applied to wiring methods.)"
Exposed. (For the purposes of WAC
				  296-155-459(3),
				  Communications systems.)
Where the circuit is in such a position that in
				  case of failure of supports or insulation, contact with another circuit may
				  result.
Externally operable.
Capable of being operated
				  without exposing the operator to contact with live parts.
Feeder.
All circuit conductors between the
				  service equipment, or the generator switchboard of an isolated plant, and the
				  final branch-circuit overcurrent device.
Festoon lighting.
A string of outdoor lights
				  suspended between two points more than 15 feet (4.57 m) apart.
Fitting.
An accessory such as a locknut,
				  bushing, or other part of a wiring system that is intended primarily to perform
				  a mechanical rather than an electrical function.
Fuse.
(Over 600 volts, nominal.)
An
				  over-current protective device with a circuit opening fusible part that is
				  heated and severed by the passage of overcurrent through it. A fuse comprises
				  all the parts that form a unit capable of performing the prescribed functions.
				  It may or may not be the complete device necessary to connect it into an
				  electrical circuit.
Ground.
A conducting connection, whether
				  intentional or accidental, between an electrical circuit or equipment and the
				  earth, or to some conducting body that serves in place of the earth.
Grounded.
Connected to earth or to some
				  conducting body that serves in place of the earth.
Grounded, effectively.
(Over 600 volts,
				  nominal.)
Permanently connected to earth through a ground connection of
				  sufficiently low impedance and having sufficient ampacity that ground fault
				  current which may occur cannot build up to voltages dangerous to
				  personnel.
Grounded conductor.
A system or circuit
				  conductor that is intentionally grounded.
Grounding conductor.
A conductor used to connect
				  equipment or the grounded circuit of a wiring system to a grounding electrode
				  or electrodes.
Grounding conductor, equipment.
The conductor
				  used to connect the noncurrent-carrying metal parts of equipment, raceways, and
				  other enclosures to the system grounded conductor and/or the grounding
				  electrode conductor at the service equipment or at the source of a separately
				  derived system.
Grounding electrode conductor.
The conductor
				  used to connect the grounding electrode to the equipment grounding conductor
				  and/or to the grounded conductor of the circuit at the service equipment or at
				  the source of a separately derived system.
Ground-fault circuit interrupter.
A device for
				  the protection of personnel that functions to deen-ergize a circuit or portion
				  thereof within an established period of time when a current to ground exceeds
				  some predetermined value that is less than that required to operate the
				  over-current protective device of the supply circuit.
Guarded.
Covered, shielded, fenced, enclosed, or
				  otherwise protected by means of suitable covers, casings, barriers, rails,
				  screens, mats, or platforms to remove the likelihood of approach to a point of
				  danger or contact by persons or objects.
Hazard.
That condition, potential or inherent,
				  which is likely to cause injury, death, or occupational disease.
Hoistway.
Any shaftway, hatchway, well hole, or
				  other vertical opening or space in which an elevator or dumbwaiter is designed
				  to operate.
Identified (conductors or terminals).
Identified, as used in reference to a conductor or its terminal, means that
				  such conductor or terminal can be recognized as grounded.
Identified (for the use).
Recognized as suitable
				  for the specific purpose, function, use, environment, application, etc., where
				  described as a requirement in this standard. Suitability of equipment for a
				  specific purpose, environment, or application is determined by a qualified
				  testing laboratory where such identification includes labeling or
				  listing.
Insulated conductor.
See "conductor."
Interrupter switch.
(Over 600 volts,
				  nominal.)
A switch capable of making, carrying, and interrupting
				  specified currents.
Intrinsically safe equipment and associated
				  wiring.
Equipment and associated wiring in which any spark or thermal
				  effect, produced either normally or in specified fault conditions, is
				  incapable, under certain prescribed test conditions, of causing ignition of a
				  mixture of flammable or combustible material in air in its most easily
				  ignitible concentration.
Isolated.
Not readily accessible to persons
				  unless special means for access are used.
Isolated power system.
A system comprising an
				  isolating transformer or its equivalent, a line isolation monitor, and its
				  ungrounded circuit conductors.
J-Box (junction box).
An electrical sheet metal
				  enclosure with openings for conduit or cable with sheet metal cover. The
				  primary purpose is for joining conductors for splicing.
Labeled.
Equipment or materials to which has
				  been attached a label, symbol or other identifying mark of a qualified testing
				  laboratory which indicates compliance with appropriate standards or performance
				  in a specified manner.
Lighting outlet.
An outlet intended for the
				  direct connection of a lampholder, a lighting fixture, or a pendant cord
				  terminating in a lampholder.
Listed.
Equipment or materials included in a
				  list published by a qualified testing laboratory whose listing states either
				  that the equipment or material meets appropriate standards or has been tested
				  and found suitable for use in a specified manner.
Location.
* Damp location. Partially protected locations under
				  canopies, marquees, roofed open porches, and like locations, and interior
				  locations subject to moderate degrees of moisture, such as some
				  basements.
* Dry location. A location not normally subject to dampness
				  or wetness. A location classified as dry may be temporarily subject to dampness
				  or wetness, as in the case of a building under construction.
* Wet location. Installations underground or in concrete
				  slabs or masonry in direct contact with the earth, and locations subject to
				  saturation with water or other liquids, such as locations exposed to weather
				  and unprotected.
Mobile X ray.
X-ray equipment mounted on a
				  permanent base with wheels and/or casters for moving while completely
				  assembled.
Motor control center.
An assembly of one or more
				  enclosed sections having a common power bus and principally containing motor
				  control units.
Outlet.
A point on the wiring system at which
				  current is taken to supply utilization equipment.
Overcurrent.
Any current in excess of the rated
				  current of equipment or the ampacity of a conductor. It may result from
				  overload (see definition), short circuit, or ground fault. A current in excess
				  of rating may be accommodated by certain equipment and conductors for a given
				  set of conditions. Hence the rules for overcurrent protection are specific for
				  particular situations.
Overload.
Operation of equipment in excess of
				  normal, full load rating, or of a conductor in excess of rated ampacity which,
				  when it persists for a sufficient length of time, would cause damage or
				  dangerous overheating. A fault, such as a short circuit or ground fault, is not
				  an overload. (See "overcurrent.")
Panelboard.
A single panel or group of panel
				  units designed for assembly in the form of a single panel; including buses,
				  automatic overcurrent devices, and with or without switches for the control of
				  light, heat, or power circuits; designed to be placed in a cabinet or cutout
				  box placed in or against a wall or partition and accessible only from the
				  front. (See "switchboard.")
Portable X ray.
X-ray equipment designed to be
				  hand-carried.
Power fuse.
(Over 600 volts,
				  nominal.)
See "fuse."
Power outlet.
An enclosed assembly which may
				  include receptacles, circuit breakers, fuseholders, fused switches, buses and
				  watt-hour meter mounting means; intended to serve as a means for distributing
				  power required to operate mobile or temporarily installed equipment.
Premises wiring system.
That interior and
				  exterior wiring, including power, lighting, control, and signal circuit wiring
				  together with all of its associated hardware, fittings, and wiring devices,
				  both permanently and temporarily installed, which extends from the load end of
				  the service drop, or load end of the service lateral conductors to the
				  out-let(s). Such wiring does not include wiring internal to appliances,
				  fixtures, motors, controllers, motor control centers, and similar
				  equipment.
Qualified person.
One familiar with the
				  construction and operation of the equipment and the hazards involved.
Qualified testing laboratory.
A properly
				  equipped and staffed testing laboratory which has capabilities for and which
				  provides the following services:
* Experimental testing for safety of specified items of
				  equipment and materials referred to in this standard to determine compliance
				  with appropriate test standards or performance in a specified manner;
* Inspecting the run of such items of equipment and
				  materials at factories for product evaluation to assure compliance with the
				  test standards;
* Service-value determinations through field inspections to
				  monitor the proper use of labels on products and with authority for recall of
				  the label in the event a hazardous product is installed;
* Employing a controlled procedure for identifying the
				  listed and/or labeled equipment or materials tested; and
* Rendering creditable reports or findings that are
				  objective and without bias of the tests and test methods employed.
Raceway.
A channel designed expressly for
				  holding wires, cables, or busbars, with additional functions as permitted in
				  this part. Raceways may be of metal or insulating material, and the term
				  includes rigid metal conduit, rigid nonmetallic conduit, intermediate metal
				  conduit, liquid-tight flexible metal conduit, flexible metallic tubing,
				  flexible metal conduit, electrical metallic tubing, underfloor raceways,
				  cellular concrete floor raceways, cellular metal floor raceways, surface
				  raceways, wireways, and busways.
Readily accessible.
Capable of being reached
				  quickly for operation, renewal, or inspections, without requiring those to whom
				  ready access is requisite to climb over or remove obstacles or to resort to
				  portable ladders, chairs, etc. (See "accessible.")
Receptacle.
A receptacle is a contact device
				  installed at the outlet for the connection of a single attachment plug. A
				  single receptacle is a single contact device with no other contact device on
				  the same yoke. A multiple receptacle is a single device containing two or more
				  receptacles.
Receptacle outlet.
An outlet where one or more
				  receptacles are installed.
Remote-control circuit.
Any electric circuit
				  that controls any other circuit through a relay or an equivalent device.
Sealable equipment.
Equipment enclosed in a case
				  or cabinet that is provided with a means of sealing or locking so that live
				  parts cannot be made accessible without opening the enclosure. The equipment
				  may or may not be operable without opening the enclosure.
Separately derived system.
A premises wiring
				  system whose power is derived from generator, transformer, or converter
				  windings and has no direct electrical connection, including a solidly connected
				  grounded circuit conductor, to supply conductors originating in another
				  system.
Service.
The conductors and equipment for
				  delivering energy from the electricity supply system to the wiring system of
				  the premises served.
Service conductors.
The supply conductors that
				  extend from the street main or from transformers to the service equipment of
				  the premises supplied.
Service drop.
The overhead service conductors
				  from the last pole or other aerial support to and including the splices, if
				  any, connecting to the service-entrance conductors at the building or other
				  structure.
Service-entrance conductors, overhead sys-tem.
The service conductors between the terminals of the service equipment and a
				  point usually outside the building, clear of building walls, where joined by
				  tap or splice to the service drop.
Service-entrance conductors, underground system.
The service conductors between the terminals of the service equipment and the
				  point of connection to the service lateral. Where service equipment is located
				  outside the building walls, there may be no service-entrance conductors, or
				  they may be entirely outside the building.
Service equipment.
The necessary equipment,
				  usually consisting of a circuit breaker or switch and fuses, and their
				  accessories, located near the point of entrance of supply conductors to a
				  building or other structure, or an otherwise defined area, and intended to
				  constitute the main control and means of cutoff of the supply.
Service raceway.
The raceway that encloses the
				  service-entrance conductors.
Shock hazard.
To exist at an accessible part in
				  a circuit between the part and ground, or other accessible parts if the
				  potential is more than 42.4 volts peak and the current through a 1,500-ohm load
				  is more than 5 milliam-peres.
Signaling circuit.
Any electric circuit that
				  energizes signaling equipment.
Switchboard.
A large single panel, frame, or
				  assembly of panels which have switches, buses, instruments, overcurrent and
				  other protective devices mounted on the face or back or both. Switchboards are
				  generally accessible from the rear as well as from the front and are not
				  intended to be installed in cabinets. (See "panelboard.")
Switches.
* General-use switch. A switch intended for use in general
				  distribution and branch circuits. It is rated in amperes, and it is capable of
				  interrupting its rated current at its rated voltage.
* General-use snap switch. A form of general-use switch so
				  constructed that it can be installed in flush device boxes or on outlet box
				  covers, or otherwise used in conjunction with wiring systems recognized by this
				  part.
* Isolating switch. A switch intended for isolating an
				  electric circuit from the source of power. It has no interrupting rating, and
				  it is intended to be operated only after the circuit has been opened by some
				  other means.
* 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, and interrupter
				  switches.
Transformer.
A transformer is an apparatus for
				  converting electrical power in an a-c system at one voltage or current into
				  electrical power at some other voltage or current without the use of rotating
				  parts.
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°C (100°F) or whose temperature is above
				  its flash point, or a Class II combustible liquid having a vapor pressure not
				  exceeding 40 psia (276 kPa) at 38°C (100°F) 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."
Statutory Authority: Chapter 49.17 RCW. 94-15-096 (Order
					 94-07), § 296-155-462, filed 7/20/94, effective 9/20/94; 93-19-142 (Order
					 93-04), § 296-155-462, filed 9/22/93, effective 11/1/93; 88-11-021 (Order
					 88-04), § 296-155-462, filed
					 5/11/88.