Computer controlled system for obtaining and processing data in explosion hazardous environments - has several mains connection stages each with respective microswitch to isolate power rails during insertion or removal process

摘要

The system (11) has mains power connecting stages (18) that include connecting plugs (19) with microswitches (20) controlling engagement. The switches ensure that the power of a respective board is switched off before the live,neutral and earth pins separate when removing a stage, and that the pins are in full contact when inserting a stage before power is switched on. The mains stages (18) have circuits to limit the output currents (12) and consists of limiting resistors (17), fuses (15), Zener diodes (14). The current levels are reduced to safe valves. ADVANTAGE - Provides safe operation and protects against explosion possibility.