Kidde IG-55 - Pressure Actuation Limitations; Pressure Trip Limitations; Pressure Operated Sirens

System Design
April 2020 3-22 06-237619-001
3-15.7 Pressure Actuation Limitations
The following sections list the limitations on the various pressure activated accessories of
the Kidde IGS system:
3-15.7.1 Pressure Trip Limitations
The maximum load to be attached to pressure trip (P/N 81-874290-000) is 100 lb (45.3
kg, based on a minimum pressure of 75 psig [5.17 bar gauge] at the pressure trip).
3-15.7.2 Pressure Operated Sirens
Pressure Operated Sirens (N
2
operated) are used to provide an audible alarm prior to the start
of and during discharge. The siren must be located upstream of the Pneumatic Discharge
Delay. A union should be installed at each siren connection, and a dirt trap shall be installed
after the last siren. The total length of 1/2-inch (DN15) pipe between the cylinders and the
sirens cannot exceed 250 ft. (76 m).
The N
2
pressure operated siren (P/N 90-981574-001) consumes approximately 0.5 to 0.9 lb.
(0.23 to 0.5 kg) of nitrogen per minute. Each siren driver cylinder can operate one or more
sirens. Table 3-15 indicates the number of sirens that can be installed on a line from any one
siren driver; the total length of actuation pipe that can be used must not exceed the limits
shown in this table.
Table 3-14. Nitrogen Pilot Cylinder Actuation Cylinder, Driver and Ancillary Limits
Detail 108 cu. in. 1040 cu. in.
Pilot/Driver Cylinder Part Number WK-877940-000 90-101040-000
Pilot Cylinder Capability Yes No
Siren Driver Capability Yes Yes
Number of 80L Agent Cylinders 44 N/A
Number of Siren Drivers 2 3
Length of Actuation Pipe to First Agent Cylinder 75 75
Length of Actuation Pipe to Siren Driver(s) 20 90
Siren Driver: Number of Sirens 1 4
Siren Driver: Length of Siren Piping 90 500
Time Delay in seconds 34/61 35/68
Table 3-15. Siren Driver Cylinder Actuation Limits
Siren Cylinder
Size
Siren Part
Number
Number of
Sirens per
Siren Driver
Maximum
Length of 1/4
in. Sch. 80
Pipe
Maximum
Length of 1/4
in. Sch. 40
Pipe
Maximum Length
of 5/16 in. x
0.032 in. Wall
Tubing
108 cu. in. 90-981574-001 1 90 ft. 90 ft. 90 ft.
1040 cu. in. 90-981574-001 4 500 ft. 500 ft. 500 ft.