4130 Annunciator Panel
The 4120 Annunciator Panel provides Overfill Prevention Monitoring in above-ground liquid storage tanks during normal daily operations. In the event of an alarm occurring, the system will inform the terminal personnel of the occurrence.
Theory of Operation
The alarm panel consists of an LED display, audible alarm, acknowledge (ACK) push button, and test (TEST) push button for each tank in the system. A mini PLC monitors the switch inputs from each tank that is connected to the system. Each of the monitored overfill switches are provided with 24 VDC inputs that are controlled by the switches for the High and High-High Alarms. The alarm system is connected to the level switches via dedicated wiring. The system uses the normally closed contacts of the switches on the tanks, so any broken wires will generate an alarm.
There is an output contact in the alarm panel for additional external lights and horns.
- Overfill Prevention