Austdac Pre-start Alarm Controller
The intrinsically safe pre-start alarm controller type APSA2 is part of the Austdac Pre-Start Alarm and Communications System type PSACS1 that provides two-way voice communications and pre-start alarm facilities along distributed plant such as conveyor belts, crushers, stacker-reclaimers and longwalls.
The pre-start alarm controller is responsible for initiating pre-start alarms, confirming pre-start alarms, tone generation and control of voice communications along the belt as well as to the surface or control room.
The APSA2 controller has two pre-start alarm request inputs, one for intrinsically safe circuits and one for non-intrinsically circuits. Pre-start alarm confirmation is provided by two sets of voltage free replay changeover contact sets.
The pre-start alarm controller can be configured with three different pre-start alarm tone sets to allow plant staff to easily determine which conveyor is starting when conveyors are in close proximity to each other e.g. longwall AFC and BSL or belt transfer stations. The APSA2 controller also distributes all power (12 volts DC) to the pre-start alarm and communications system
The pre-start alarm controller also provides the necessary switching for voice communications, signalling tones and pre-start alarm tones to prevent pre-start alarm tones from entering the surface pair and control room.