Wash. Admin. Code § 296-24-95713 - Special systems
(1)
Systems
over 600 volts, nominal. This subsection covers the general requirements
for all circuits and equipment operated at over 600 volts.
(a)
Aboveground wiring methods.
(i) You must install aboveground conductors
in rigid metal conduit, in intermediate metal conduit, in electrical metallic
tubing, in rigid nonmetallic conduit, in cable trays, as busways, as cablebus,
in other identified raceways, or as open runs of metal-clad cable suitable for
the use and purpose. In locations accessible to qualified persons only, open
runs of Type MV cables, bare conductors, and bare busbars are also permitted.
Busbars must be either copper or aluminum. Open runs of insulated wires and
cables having a bare lead sheath or a braided outer covering must be supported
in a manner designed to prevent physical damage to the braid or
sheath.
(ii) You must enclose
conductors emerging from the ground in approved raceways.
(b)
Braid-covered insulated conductors
Open installations. The braid on open runs of braid-covered insulated
conductors must be flame retardant or must have a flame-retardant saturant
applied after installation. You must strip back this treated braid covering a
safe distance at conductor terminals, according to the operating
voltage.
(c)Insulation
shielding.
(i) You must remove
metallic and semiconductor insulation shielding components of shielded cables
for a distance dependent on the circuit voltage and insulation. You must
provide stress reduction means at all terminations of factory-applied
shielding.
(ii) You must ground
metallic shielding components such as tapes, wires, or braids, or combinations
thereof, and their associated conducting and semiconducting components.
(d)
Moisture or
mechanical protection for metal-sheathed cables. Where cable conductors
emerge from a metal sheath and where protection against moisture or physical
damage is necessary, the insulation of the conductors must be protected by a
cable sheath terminating device.
(e)Interrupting and isolating
devices.
(i) Circuit breaker
installations located indoors must consist of metal-enclosed units or
fire-resistant cell-mounted units. In locations accessible only to qualified
employees, open mounting of circuit breakers is permitted. You must provide a
means of indicating the open and closed position of circuit breakers.
(ii) Where fuses are used to
protect conductors and equipment, you must place a fuse in each ungrounded
conductor. Two power fuses may be used in parallel to protect the same load, if
both fuses have identical ratings, and if both fuses are installed in an
identified common mounting with electrical connections that will divide the
current equally. Power fuses of the vented type may not be used indoors,
underground, or in metal enclosures unless identified for the use.
(iii) Fused cutouts installed in buildings or
transformer vaults must be of a type identified for the purpose. Distribution
cutouts may not be used indoors, underground, or in metal enclosures. They must
be readily accessible for fuse replacement.
(iv) Where fused cutouts are not suitable to
interrupt the circuit manually while carrying full load, you must install an
approved means to interrupt the entire load. Unless the fused cutouts are
interlocked with the switch to prevent opening of the cutouts under load, you
must place a conspicuous sign at such cutouts reading: "WARNING-DO NOT OPERATE
UNDER LOAD."
(v) You must provide
suitable barriers or enclosures to prevent contact with nonshielded cables or
energized parts of oil-filled cutouts.
(vi) Load interrupter switches may be used
only if suitable fuses or circuits are used in conjunction with these devices
to interrupt fault currents.
(A) Where these
devices are used in combination, you must coordinate them electrically so that
they will safely withstand the effects of closing, carrying, or interrupting
all possible currents up to the assigned maximum short-circuit
rating.
(B) Where more than one
switch is installed with interconnected load terminals to provide for alternate
connection to different supply conductors, you must provide each switch with a
conspicuous sign reading:
"WARNING-SWITCH MAY BE ENERGIZED BY BACKFEED."
(vii)
You must provide a means (for example, a fuse-holder and fuse designed for the
purpose) to completely isolate equipment for inspection and repairs. Isolating
means that they are not designed to interrupt the load current of the circuit
and must be either interlocked with an approved circuit interrupter or provided
with a sign warning against opening them under load.
(f)Mobile and portable
equipment.
(i) You must provide a
metallic enclosure on the mobile machine for enclosing the terminals of the
power cable. The enclosure must include provisions for a solid connection for
the grounding terminal to effectively ground the machine frame. The method of
cable termination used must prevent any strain or pull on the cable from
stressing the electrical connections. The enclosure must have provision for
locking so that only authorized qualified persons may open it and you must mark
it with a sign warning of the presence of energized parts.
(ii) All energized switching and control
parts must be enclosed in effectively grounded metal cabinets or enclosures.
Circuit breakers and protective equipment must have the operating means
projecting through the metal cabinet or enclosure so these units can be reset
without locked doors being opened. You must lock enclosures and metal cabinets
so that only authorized qualified persons have access and you must mark them
with a sign warning of the presence of energized parts. You must guard
collector ring assemblies on revolving-type machines (shovels, draglines, etc.).
(g)
Tunnel
installations. This subsection applies to installation and use of
high-voltage power distribution and utilization equipment that is portable or
mobile, such as substations, trailers, cars, mobile shovels, draglines, hoists,
drills, dredges, compressors, pumps, conveyors, and underground excavators.
(i) You must install conductors in tunnels in
one or more of the following:
(A) Metal
conduit or other metal raceway;
(B)
Type MC cable; or
(C) Other
approved multiconductor cable.
(ii) Multiconductor portable cable may supply
mobile equipment.
(iii) You must
also locate or guard conductors and cables so as to protect them from physical
damage. You must run an equipment grounding conductor with circuit conductors
inside the metal raceway or inside the multiconductor cable jacket. The
equipment grounding conductor may be insulated or bare.
(iv) Bare terminals of transformers,
switches, motor controllers, and other equipment must be enclosed to prevent
accidental contact with energized parts.
(v) Enclosures for use in tunnels must be
drip-proof, weatherproof, or submersible as required by the environmental
conditions.
(vi) Switch or
contactor enclosures may not be used as junction boxes or raceways for
conductors feeding through or tapping off to other switches, unless special
designs are used to provide adequate space for this purpose.
(vii) You must install a disconnecting means
that simultaneously opens all ungrounded conductors at each transformer or
motor location.
(viii) You must
effectively ground and bond all nonenergized metal parts of electric equipment
and metal raceways and cable sheaths to all metal pipes and rails at the portal
and at intervals not exceeding 1000 feet throughout the
tunnel.
(2)Emergency power systems. This
subsection applies to circuits, systems, and equipment intended to supply power
for illumination and special loads in the event of failure of the normal
supply.
(a)Wiring methods. You
must keep emergency circuit wiring entirely independent of all other wiring and
equipment and may not enter the same raceway, cable, box, or cabinet or other
wiring except either where common circuit elements suitable for the purpose are
required, or for transferring power from the normal to the emergency
source.
(b)
Emergency
illumination. Emergency illumination must include all required means of
egress lighting, illuminated exit signs, and all other lights necessary to
provide illumination. Where emergency lighting is necessary, you must arrange
the system so that the failure of any individual lighting element, such as the
burning out of a light bulb, cannot leave any space in total
darkness.
(c)Signs.
(i) You must place a sign at the service
entrance equipment indicating the type and location of on-site emergency power
sources. However, a sign is not required for individual unit
equipment.
(ii) Where the grounded
circuit conductor connected to the emergency source is connected to a grounding
electrode conductor at a location remote from the emergency source, there must
be a sign at the grounding location that must identify all emergency and normal
sources connected at that location.
(3)Class 1, Class 2, and Class 3 remote
control, signaling, and power-limited circuits.
(a)
Classification. Class 1,
Class 2, and Class 3 remote control, signaling, or power-limited circuits are
characterized by their usage and electrical power limitation that
differentiates them from light and power circuits. These circuits are
classified in accordance with their respective voltage and power limitations as
summarized in (a)(i) through (iii) of this subsection.
(i) You must supply a Class 1 power-limited
circuit from a source having a rated output of not more than 30 volts and 1000
volt-amperes.
(ii) A Class 1 remote
control circuit or a Class 1 signaling circuit must have a voltage not
exceeding 600 volts; however, the power output of the source need not be
limited.
(iii) The power source for
a Class 2 or Class 3 circuit must be listed equipment marked as a Class 2 or
Class 3 power source, except as follows:
(A)
Thermocouples do not require listing as a Class 2 power source; and
(B) A dry cell battery is considered an
inherently limited Class 2 power source, provided the voltage is 30 volts or
less and the capacity is less than or equal to that available from
series-connected No. 6 carbon zinc cells.
(b)Marking. You must durably
mark a Class 2 or Class 3 power supply unit where plainly visible to indicate
the class of supply and its electrical rating.
(c)
Separation from conductors of other
circuits. Cables and conductors of Class 2 and Class 3 circuits may not
be placed in any cable, cable tray, compartment, enclosure, manhole, outlet
box, device box, raceway, or similar fitting with conductors of electric light,
power, Class 1, nonpower-limited fire alarm circuits, and medium power
network-powered broadband communications cables unless a barrier or other
equivalent form of protection against contact is employed.
(4)
Fire alarm systems.
(a)Classifications. You must
classify fire alarm circuits either as nonpower limited or power
limited.
(b)Power
sources. The power sources for use with fire alarm circuits must be
either power limited or non-power limited as follows:
(i) The power source of nonpower-limited fire
alarm (NPLFA) circuits must have an output voltage of not more than 600 volts,
nominal; and
(ii) The power source
for a power-limited fire alarm (PLFA) circuit must be listed equipment marked
as a PLFA power source.
(c)Separation from conductors of other
circuits.
(i) Nonpower-limited fire
alarm circuits and Class 1 circuits may occupy the same enclosure, cable, or
raceway provided all conductors are insulated for maximum voltage of any
conductor within the enclosure, cable, or raceway. Power supply and fire alarm
circuit conductors are permitted in the same enclosure, cable, or raceway only
if connected to the same equipment.
(ii) Power-limited circuit cables and
conductors may not be placed in any cable, cable tray, compartment, enclosure,
outlet box, raceway, or similar fitting with conductors of electric light,
power, Class 1, nonpower-limited fire alarm circuit conductors, or medium power
network-powered broadband communications circuits.
(iii) You must separate power-limited fire
alarm circuit conductors at least 2 inches from conductors of any electric
light, power, Class 1, nonpower-limited fire alarm, or medium power
network-powered broadband communications circuits unless a special and equally
protective method of conductor separation is employed.
(iv) Conductors of one or more Class 2
circuits are permitted within the same cable, enclosure, or raceway with
conductors of power-limited fire alarm circuits provided that the insulation of
Class 2 circuit conductors in the cable, enclosure, or raceway is at least that
needed for the power-limited fire alarm circuits.
(d)
Identification. You must
identify fire alarm circuits at terminal and junction locations in a manner
that will prevent unintentional interference with the signaling circuit during
testing and servicing. You must durably mark power-limited fire alarm circuits
as such where plainly visible at terminations.
(5)
Communications systems. This
subsection applies to central-station-connected and
noncentral-station-connected telephone circuits, radio and television receiving
and transmitting equipment, including community antenna television and radio
distribution systems, telegraph, district messenger, and outside wiring for
fire and burglar alarm, and similar central station systems. These
installations need not comply with the provisions of WAC
296-24-95703 through
296-24-95713(4),
except for WAC
296-24-95705(3)(a)
and 296-24-95711.
(a)Protective devices.
(i) You must provide a listed primary
protector on each circuit run partly or entirely in aerial wire or aerial cable
not confined within a block.
(ii)
You must also provide a listed primary protector on each aerial or underground
circuit when the location of the circuit within the block containing the
building served allows the circuit to be exposed to accidental contact with
electric light or power conductors operating at over 300 volts to
ground.
(iii) In addition, where
there exists a lightning exposure, you must protect each interbuilding circuit
on premises by a listed primary protector at each end of the interbuilding
circuit.
(b)Conductor location.
(i) You must keep lead-in or aerial-drop
cables from a pole or other support, including the point of initial attachment
to a building or structure, away from electric light, power, Class 1, or
nonpower-limited fire alarm circuit conductors so as to avoid the possibility
of accidental contact.
(ii) You
must maintain a separation of at least 6 feet between communications wires and
cables on buildings and lightning conductors.
(iii) Where communications wires and cables
and electric light or power conductors are supported by the same pole or run
parallel to each other in-span, you must meet the following conditions:
(A) Where practicable, you must locate
communication wires and cables on poles below the electric light or power
conductors; and
(B) Communications
wires and cables may not be attached to a cross arm that carries electric light
or power conductors.
(iv) You must separate indoor communications
wires and cables at least 2 inches from conductors of any electric light,
power, Class 1, nonpower-limited fire alarm, or medium power network-powered
broadband communications circuits, unless a special and equally protective
method of conductor separation, approved for the purpose, is
employed.
(c)Equipment location. You must
locate outdoor metal structures supporting antennas, as well as self-supporting
antennas such as vertical rods or dipole structures, as far away from overhead
conductors of electric light and power circuits of over 150 volts to ground as
necessary to prevent the antenna or structure from falling into or making
accidental contact with such circuits.
(d)Grounding.
(i) If exposed to contact with electric light
and power conductors, you must ground the metal sheath of aerial cables
entering buildings or you must interrupt them close to the entrance to the
building by an insulating joint or equivalent device. Where protective devices
are used, you must ground them in an approved manner.
(ii) You must permanently and effectively
ground masts and metal structures supporting antennas without splice or
connection in the grounding conductor.
(iii) Transmitters must be enclosed in a
metal frame or grill or separated from the operating space by a barrier, all
metallic parts of which are effectively connected to ground. You must
effectively ground all external metal handles and controls accessible to the
operating personnel. Unpowered equipment and enclosures are considered to be
grounded where connected to an attached coaxial cable with an effectively
grounded metallic shield.
(6)Solar photovoltaic systems.
This subsection covers solar photovoltaic systems that can be interactive with
other electric power production sources or can stand alone with or without
electrical energy storage such as batteries. These systems may have AC or DC
output for utilization.
(a)
Conductors
of different systems. Photovoltaic source circuits and photovoltaic
output circuits may not be contained in the same raceway, cable tray, cable,
outlet box, junction box, or similar fitting as feeders or branch circuits of
other systems, unless the conductors of the different systems are separated by
a partition or are connected together.
(b)Disconnecting means. You must
provide means to disconnect all current-carrying conductors of a photovoltaic
power source from all other conductors in a building or other structure. Where
a circuit grounding connection is not designed to be automatically interrupted
as part of the ground-fault protection system, a switch or circuit breaker used
as disconnecting means may not have a pole in the grounded conductor.
(7)Integrated electrical
systems.
(a)
Scope. This
subsection covers integrated electrical systems, other than unit equipment, in
which orderly shutdown is necessary to ensure safe operation. An integrated
electrical system as used in this section must be a unitized segment of an
industrial wiring system where all of the following conditions are met:
(i) The conditions of maintenance and
supervision ensure that only qualified persons will service the system;
and
(ii) Effective safeguards are
established and maintained.
(b)
Location of overcurrent devices in
or on premises. Overcurrent devices that are critical to integrated
electrical systems need not be readily accessible to employees as required by
WAC 296-24-95705(6)(a)(iv)
if they are located with mounting heights to ensure security from operation by
nonqualified persons.
Notes
Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060, and chapter 49.17 RCW. 12-16-064, § 296-24-95713, filed 7/31/12, effective 9/1/12.
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