The ALSTOM GENERAL MONITORS 580 20703-1 is a highly reliable dual-channel combustible gas monitoring system designed for continuous detection of explosive hydrocarbon vapors. The system utilizes catalytic bead sensors in a Wheatstone Bridge circuit to measure gas concentrations independently across two remote locations. Its solid-state controller is engineered for non-hazardous area mounting and automatically displays the highest reading between the two channels. With fully adjustable alarm set points and dedicated malfunction circuitry, it provides a robust safety interface for oil and gas platforms, chemical processing plants, and industrial fuel loading facilities.

Product Q&A

Q1: How does the “Higher Reading” display logic function in the Model 580? A1: In automatic mode, the controller’s meter or digital display always shows the signal from whichever of the two sensor channels is detecting a higher concentration of gas. An LED indicator on the front panel identifies which channel is currently being displayed, though an operator can manually override this to check the second channel.

Q2: What conditions will trigger the “Malfunction” relay? A2: The malfunction relay is a “fail-safe” output that activates under specific fault conditions, including low input power, a total power outage, loose sensor connections at the controller or sensor housing, or a severed sensor cable. This relay is normally energized to ensure a fault is signaled even if power to the monitor itself is lost.

Q3: Can the 580 monitor be used for toxic gases like H2S? A3: No, the Model 580 is specifically designed for combustible gases (LEL range) using catalytic bead technology. For toxic gas monitoring in parts per million (ppm), a different series—such as the General Monitors 2280A or specialized electrochemical sensors—would be required.

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