Batteries
The hydrogen gas given off from
batteries that are located in confined areas can, at certain
concentrations, become an explosion hazard. Therefore, a continuously
operating exhaust system should be installed when batteries are
located in a room sized to contain only the battery(ies) or are
located in a confined space where the buildup and retention of
hydrogen gas could reach potentially explosive concentrations.
The
entrance door(s) to a battery room should have a "No Smoking"
or "No Open Flame" warning sign posted on it. Lighting
switches should be located outside of the room. All codes should be
followed concerning the type of lighting fixtures, wiring, and
installation of eye-wash stations. Precautions should also be taken
to assure that the acid fumes will not be present in a concentration
sufficient to cause damage to nearby relay contacts.
Surge arresters
Surge arresters should be properly
sized and located to minimize the possibility of an equipment fire
initiated from surges.
Direct-stroke lightning
If needed, direct-stroke lightning
protection, e.g., grounded lightning masts, static wires, etc.,
should be installed so that all equipment and buildings are
protected. Guidance in the installation of this protection can be
found in ANSI/ NFPA 780-1992 [B30].
Grounding
All equipment in the substation should
be properly grounded with correctly sized grounding conductors and
proper terminations to dissipate fault currents. This is necessary to
prevent failure of the grounding conductor or termination, which
could result in more severe equipment damage and an associated fire.
Guidance in grounding equipment can be found in IEEE Std 80-1986
[B45].
Fault-sensing and interrupting devices
The proper relaying or fault-sensing
devices in combination with an interrupting device should protect all
circuits and equipment. The combination of the devices used should
operate and isolate the fault before any further and more serious
problems could occur.
Metal-clad switchgear
Consideration should be given to the
installation of a fixed extinguishing system for the protection of
metal-clad switchgear that contains oil-filled equipment.
Consideration should be given to the installation of smoke detectors
on the ceiling of the switchgear room above the switchgear lineups.
For guidance, see FM Data Sheet 5-19 [B41].
Oil-filled reactors
Consideration should be given to the
installation of a fixed extinguishing system for the protection of
oil-filled reactors. If the reactor(s) is enclosed in a
sound-reducing housing, the fixed fire-extinguishing system should be
installed both inside and outside the housing.
Power capacitors
Power capacitor units located outdoors,
which contain a combustible dielectric fluid, should be a minimum of
10 ft (3.0 m) from any building not of fire-resistive construction.
Capacitor units located indoors, which contain a flammable dielectric
fluid, should be separated from adjacent areas by a 1 h fire-rated
barrier.
Diesel or gasoline engines
A substation may contain diesel-,
propane-, or gasoline-powered engines for fire pumps or standby
electrical power. Installation of these engines should conform to
ANSI/NFPA 37-1994 [B19]. Electrical apparatus on engines and
generators should be fully spark-protected. For design requirements
for propane fuel use, see ANSI/NFPA 58-1995 [B20].
Fuel-handling systems
Substation fuel-handling systems should
conform to ANSI/NFPA 30-1993 [B18]. Buried tanks and piping should be
corrosion-protected, and loading points for fuel should be located at
the perimeter of the substation. Underground tanks should be located
in a clearly marked area and should not be subjected to vehicle
loads.
Relay and control panels
Panels should be designed and
constructed to meet the recommendations for flame retardance
contained in IEEE Std 420-1982 [B48].
Gas-insulated components
Consideration should be given to the
control of SF6 gas and the mitigation of gas by-products that may be
generated as either a direct or indirect result of fire. Precautions
regarding the harmful effects of SF6 gas and SF6 gas by-products are
given in IEEE Std C37.122-1993 [B43] and IEEE Std C37.122.1-1993
[B44].
High-pressure oil-filled-cable pumping
plants
Consideration should be given to the
installation of a fixed extinguishing system for the protection of
oil-filled-cable pumping plants and storage tanks.
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