operated gong at locations indicated. Connect gong to the control unit so
that gong sounds the code of each operated fire alarm box.
2.4
CIRCUIT PROTECTION DEVICES
**************************************************************************
NOTE: The one-half ampere protection on tie-line
circuits shall be omitted at all stations other than
the alarm control center.
**************************************************************************
Protect box circuit and tie-line conductors entering the alarm control
center by the following devices, in the order named, starting from the
exterior circuit. Provide lightning arresters at locations on the system
[as required by NFPA 1221.] [and as indicated.]
a.
A fuse rated at 7 amperes and not less than 2000 volts.
b.
A lightning arrestor.
c.
A fuse, or circuit breaker, rated at one-half ampere, fast-blow
for solid state circuits.
2.5
STANDARD FIRE ALARM BOXES
Connect manual stations into alarm initiating circuit. Provide coded,
positive, noninterfering type with succession features. Provide boxes
capable of transmitting through ground in the event of a single open in the
circuit. Provide pre-wound, open-door-pull-lever type boxes that conform
to applicable requirements of UL 38. The house mechanism shall be in a
weatherproof cottage-shell type of housing with metallic bronze or
nickel-alloy or rigid plastic code number plate mounted on the exterior
face of the cottage shell. Stations requiring breaking of glass or plastic
panels for operation are not acceptable; however, stations employing glass
rods are acceptable. Gravity or mercury switches are not acceptable.
Finish the housing in gloss [red] [yellow] enamel with a reflective, highly
visible label imprinted with the word "FIRE" in minimum 50 mm 2 inch block
characters on both sides of the box. Code wheel shall be metallic [or
nylon derivative] and code shall be as developed by the coding plan for the
code wheel location. Operation of the actuating pull lever shall cause the
box to transmit 4 complete round groups of code to all gongs, recorders,
and other devices on the circuit to which the pull lever is connected.
Driving springs shall have the capability to transmit not less than 8
complete 4-round groups of code before being rewound. Design boxes for
operation on 100 milliamperes dc, but with capability of full operation at
70 milliamperes and up to 120 milliamperes. Box mechanism shall be capable
of transmitting signals at varying rates of speed ranging from electrical
impulses at 3 1/4 second intervals to 1/4 second intervals and shall be
field adjustable to any speed within this range. Equip each box with
manual signaling key, silent test device, and box shunt device.
2.5.1
Master Fire Alarm Boxes
Provide type identical to standard boxes except that, in addition, equip
each master box with a [shunt] [local-energy] type auxiliary tripping coil
for connection to building protective or alarm system devices.
SECTION 13851N
Page 18
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