COMPONENTS
into the protected space within 10 seconds following
the start of the discharge.
The components of the Halon system include the
following:
SYSTEM ACTUATION AND FEATURES
Halon 1301 cylinders
Each system is usually provided with more than
5-pound CO2 actuators
one CO2 actuator station. The actuators can be
Vent fittings
installed either inside or outside the space. Features of
the system include automatic ventilation shutdown,
1/4-inch copper nitrogen tubing connections
actuation of local and remote alarms, manual time
with a 4-inch loop that are called actuation lines
delay bypass, and halon discharge indicator light.
Flexible discharge hoses
SYSTEM OPERATION
Check valve
Time-delay device
Normal operation of the halon system may be
accomplished by performing the following actions:
Time-delay device bypass valve
1. Break the glass or open the enclosure at a remote
CO2 actuation system piping
actuating stations. Remove the safety pin, which is
Pressure switches
secured by a lead and wire seal.
Halon discharge piping
2. Fully operate the discharge lever and secure it in
the OPERATE position. The released carbon dioxide
Discharge nozzles
will immediately actuate two pressure switches. One
pressure switch operates lights and horns (or bells)
In-line filter
within the space, and a bell and amber system actuated
Electrically operated alarms and indicators
light outside the space at actuating stations and space
accesses. The other pressure switch will initiate shut
LOCATION
down of ventilation fans and operate any installed vent
closures.
The usual location for Halon cylinders is inside a
3. If alarms do not operate, or ventilation does not
protected compartment within a space; however, they
shut off, pull out the reset/actuation knob on the
may be located outside or in a Halon cylinder room.
associated pressure switch. If operation still does not
Halon systems placed in machinery spaces (Main
occur, manually shut off ventilation systems, and pass
Machinery Rooms, Firerooms, Engine Rooms,
the word to evacuate the space.
Auxiliary Machinery Rooms) will have 60-second
time delays. In compartments other than Machinery
4. After the time delay operates, the carbon
Spaces, Halon systems usually have a 30-second time
dioxide pressure will operate the Halon cylinder valves
delay, and only a primary Halon system. Engine
to discharge Halon to its associated nozzles. A third
enclosures or modules have a 30-second time delay for
pressure switch downstream of the time delay device
both primary and reserve Halon systems.
will then actuate a red light indicating Halon discharge.
CAPABILITIES
5. In the event the timing of the time delay device
exceeds 70 seconds (for a 60-second device), or
Each system is designed so a single discharge of
35 seconds (for a 30-second device), the time delay
Halon 1301 provides a concentration of 5 to 7 percent
should be bypassed by opening the time delay bypass
Halon 1301 by volume of air throughout the protected
valve.
s p a c e . S u ffi c i e n t H a l o n i s r e q u i r e d s o t h e
WARNING
concentration will remain at a minimum of 5 percent
for 15 minutes. Some Halon protected spaces have a
duplicate reserve Halon system to supplement the
The time delay bypass valve should not
primary one. Each Halon fixed-flooding system is
be operated until after the full delay time of 30
designed to discharge completely the Halon 1301 gas
or 60 seconds has passed.
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