General Information

Preaction-Pac General Information

Introduction. The United Fire Systems Preaction-Pac is a fully assembled and factory tested pre-action fire suppression system, including pre-action valve, trim, and control panel providing one complete zone of pre-action water sprinkler fire protection.  All components are contained in two steel enclosures assembled one above the other.  The system pressure gages and the required manual release handle are mounted on the front of the lower enclosure.  The system detection and control panel is mounted behind a door in the upper enclosure with a clear polycarbonate window allowing visual access to the system indicators.  Lockable latches on both doors permit authorized access to all system components.  Both enclosures are finished in powder-coat red paint.  Gaskets provides sealing of the enclosure doors.  Knockouts permit easy attachment of external electrical conduits.

Pre-Action-Valve. The pre-action valve installed in the Preaction-Pac is a low-differential, latched clapper valve that uses a unique direct-acting diaphragm to separate the system water supply from the system piping.  The positive latching system uses the supply water pressure to hold the clapper shut.  When the water pressure in the diaphragm chamber is released, the latch retracts from the clapper and the valve actuates.  The low differential and unique latch and actuator design of the valve allows the valve to be self-resetting.

Piping.  Water inlet pipe connections are located on the lower left and lower right sides and the upper right corner of the lower enclosure. (NOTE:  Assemblies equipped with 1/2HP compressors do not have upper right corner inlet connection.)  The unused inlets are left plugged.  Grooved pipe is used for the inlet connection.  The water outlet pipe connection is located at the top center of the lower enclosure, behind the upper enclosure.  The drain connection is accessible within the lower enclosure, and knockouts are provided allowing exit of the drain from either side.   All pipe connections are done in the lower enclosure.

Control Panel.  A conventional or addressable releasing control panel is factory-installed in the upper enclosure.  Programming for a basic pre-action system is factory programmed and tested.  Additional programming may be necessary after installation to suit field conditions.  This manual provides complete instructions for additional programming.  All necessary internal wiring connections are factory-installed and tested.  (Preaction-Pac units are also available without an integral control panel.)

Wiring.  All wiring from the integral control panel to the valve solenoid and all switches is factory installed and tested.  Wiring for compressor power and control is also factory installed and tested.  All field wiring for control panel power, compressor power, detection circuits, notification appliance circuits, and circuits requiring contact closure is connected to terminal strips in the upper enclosure.  No access to the lower enclosure is necessary to complete the wiring installation.

Compressor.  The compressor for air pressurization of the pre-action sprinkler piping is pre-installed, wired and adjusted.  Three sizes of compressor are available, depending on the volume of installed piping to be pressurized.  The compressor is mounted using molded rubber mounts and bushings to minimize noise and vibration during motor operation.  A compressor disconnect switch is located in the upper enclosure. (Preaction-Pac units are also available without compressors, pre-configured for use with the United Fire Systems Nitrogen-Pac Sprinkler Corrosion Inhibiting System.)

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