14
HELIX™ Manual
(P/N 26291)
Chapter 2: System Components
Rev A (February 2018)
HELIX™
PCU Fire Suppression System
2.5.5 Linear Actuator (P/N 20500
-
R)
The Linear Actuator is a device when electrically activated extends a metal
shaft which mechanically opens the Agent Cylinder Valve when used in an
Electric Control Head or opens a Nitrogen Cylinder when used in an Electric
Nitrogen Actuator. Once activated it cannot be reused and must be
replaced. Service life of the Linear Actuator is 6 years after which it must be
replaced. Shelf life of the Linear Actuator is 10 years after which it must be
replaced whether it has been placed in service or not. Each Linear Actuator
is
supplied with a Mylar style label for identifying date of manufacture. An O
-
ring (P/N 17137) is provided with each Linear Actuator and must be used
each time that a Linear Actuator is installed. See Sections 4.3.1 and 4.5 for
installation instructions.
Use only 20500
-
R Linear Actuator for actuating a
HELIX Fire Suppression System.
O
-
RING
(P/N 17137)
Figure 2.5.5
2.5.6 50 psi Pressure Switch (P/N 22573
-
R or 23850
-
R)
The 50 psi Pressure Switch is an optional switch designed to be used in the
Pneumatic Actuation Network. The Switch (P/N 22573
-
R non
-
terminated version;
P/N 23850
-
R terminated version) is normally in the open position and closes when
subjected to nitrogen pressure in excess of 50 psi. The Switch is threaded with a
1/4” NPT male port. The Switch must be installed in a tee in the Pneumatic
Actuation Network just before the first Pneumatic Control Head (P/N 10147
-
R). The
Switch can be utilized to send a signal such as “system discharge” back to the
associated
electronics control unit; or to an external relay for sounding an auxiliary
alarm or illuminating a light in the event of system discharge. Terminated Switches
may be used in the detection circuit of the STRIKE
ECS. See Section 4.4 for
installation instructions.
Figure 2.5.7
2.5.7 Agent Cylinder Pressure Switch (Reference Only)
The Agent Cylinder Pressure Switch is supplied with and connected directly to the Agent Cylinder.
This switch is designed to monitor Agent Cylinder pressure. The switch is closed in a pressurized
Agent Cylinder and opens when Agent Cylinder pressure drops below 270 psi, indicating a
discharged or leaking Agent Cylinder.
Figure 2.5.6
