2.8.1 Control Switches
2.8.1.1 Manual Control – Electrical Pull Station and Manual Release Station
The cylinder valve can be electrically actuated by means of a Manual Control – Electrical Pull Station and Manual Release Station wired to the U.L. Listed Control Panel for releasing device service. The releasing panel must be compatible with Unique Fire Electric Solenoids. This configuration can be backed up with a Local Manual Control mounted on top of a Top Plug Adapter.
2.8.1.2 Main-Reserve Selector Switch
The “Main” to “Reserve” Switch (Part Number: UFI 50195-1) is used with systems that incorporate main and reserve (back-up) agent storage. The switch may utilize 1 or 2 Form “C” Contact Blocks, which will provide an electrical path to either the “Main” or “Reserve” cylinder electric solenoid. Following a system discharge, reset all field devices. Once all devices are in a stand-by status, the Main-Reserve Switch may be moved to the “Reserve” position. The Control Panel may then be reset to a normal mode for uninterrupted system protection. The empty “Main” container can be removed for recharge. After the container in the “Main” system has been recharged, the switch may be returned to the “Main” position. The switch is mounted on a standard 4” electrical enclosure.
2.8.1.3 Abort Station
The Abort Station (Part Number: UFI 88105) is designed to be used in conjunction with other system equipment. It provides a temporary manual means, whereby the system actuation circuit may be interrupted when operated prior to the circuit actuation. The unit employs a momentary contact push button switch. While depressed, the switch causes the agent release circuit to be manually delayed. Upon release of the Abort Station, the release circuit will follow the specific configuration of the U.L. Listed Control Panel. The Abort Station is mounted on a standard double gang electrical enclosure.
2.8.1.4 Releasing Circuit Disable Switch
The Releasing Circuit Disable Switch (Part Number: UFI 88205) is U.L. Listed and has dual functions. One is to cut the circuit continuity of the electric solenoid, and another is to give a signal to the control panel to indicate that there is no circuit continuity in the electric solenoid to initiate the discharge of the agent. This is accomplished by using a keyed lockout to lock the system or to disconnect the electric solenoid electronically during maintenance or inspection.
The following is necessary to comply with the NFPA 2001 (Latest Edition) and UL 2166 requirements.
1. Releasing Circuit – U.L. Listed Fire Control Panel is provided with a disconnect switch to allow the system to be tested without actuating the Electric Solenoid. The function of the releasing circuit is to temporarily disable the function of the system by opening the circuit continuity.
2. Supervisory Zone – Operation of a disconnect switch or a disable function shall cause a supervisory signal at the fire alarm control unit. When the switch is disabled, it will cause the annunciation of a supervisory signal at a required operator interface for the U.L. Listed Control Panel. This is to ensure that the Releasing Circuit Disable Switch is switched back to its normal condition after maintenance/inspection.
Please refer to the U.L. Listed Control Panel Manual and the U.L. Listed Releasing Circuit Disable Switch for proper wiring installation.
2.8.2 Initiating Devices
2.8.2.1 Pressure Supervisory Switch
The Pressure Supervisory Switch ( Figure 2-40) is to monitor the pressure within the cylinder. It is attached to the port marked “P”. If the cylinder to which it is attached leaks, its pressure drops to its release pressure or below, the switch contact will operate giving an indication on the Control Panel that the cylinder has lost pressure.
One version of the switch is normally closed (N.C.) and the second version is normally open (N.O.). The switch is referenced in the no pressure condition. When the cylinder is pressurized until the actuation pressure is reached, the contact for the normally closed (N.C.) switch will shift from normally closed to normally open status and vice versa for the normally open (N.O.) switch. However, when the cylinder is de-pressurized until the release pressure is reached, the contact will shift back to its original status. When the switch is used on a standard supervisory input circuit, there will be no distinction between a wiring fault and a device actuation.
Pressure Supervisory Switch Guard (P/N: UFI 70215-2) is offered in order to protect pressure supervisory switch (M10 thread) during assemblies, installations, services and maintenances.
2.8.2.2 Pressure Operated Switch
The switch (Part Number: UFI 50339) is provided to furnish additional electrical contacts for control purposes at time of discharge. See Figure 2-41 for details. The switch may be installed into the same pneumatic tubing for the Piston Actuators provided the maximum length for tubing outlined in Table 2-7 is not exceeded. The switch may also be connected to any point of the discharge piping between the cylinder and the nozzle. An external manual reset button is provided on the pressure switch. After the system is activated, the reset button must be depressed in order to return the device being controlled back to the pre-discharge state.
Engineering Specifications:
Electrical Rating: 15 Amps – 125/250 VAC; Switch: SPDT snap action;
Contacts: One N.O. and One N.C. Activating Pressure: 10 ~ 100psi
2.8.3 Liquid Level Indicator
The Unique Fire Liquid Level Indicator is a
simple, manually operated device, which provides a means to determine the Clean Agent liquid level in vertically mounted agent storage containers. Once the liquid level is determined, it can then be converted into pounds (kilograms) of Clean Agent present in the agent storage container.
A magnet equipped float moves with the liquid level along the unit stem. Level readout is obtained by simply removing the protective cap and pulling out a calibrated tape until the magnetic interlock with the float is felt. With the tape in this position, the readout is obtained at the point where the tape emerges from the unit housing. With the graph (per cylinder size), the tape reading is converted to lbs. of Clean Agent in the cylinder. Accurate readings can be obtained over a 40 oF (4.44 oC) to 90 oF (32.22 oC) temperature range. Tolerance is ±2% of cylinder fill weight. The part numbers of Liquid
Level Indicator are given in Table 2-14. refer to page 56