The intrinsically safe 20x20-LCD user interface on the unit’s face can be mounted remotely. Programming of configuration and all options are accomplished through a set of menu-driven buttons. Five color LEDs give easy indication of operation, distinctively showing safe pressure, enclosure power, rapid exchange, system bypass and alarm faults.
Four intrinsically safe inputs activate various EPCU actions and outputs. They accept only dry contact for activation, and are supplied by the EPCU’s galvanically isolated barrier. Inputs for various actions are assigned through the user-interface controller. Only one function can operate an input. Inputs can bypass the system for live maintenance on the enclosure. In addition to many other actions and outputs, the intrinsic safety inputs activate the auxiliary relays, energize the rapid exchange valve, de-energize the enclosure contacts, and shut the system down.
Two normally open, dry contacts for enclosure power can be energized only after a successful purge and achieving a minimum enclosure pressure.
Purging can be based on a known purge rate and a fixed time, or done dynamically with the time determined by the flow rate being measured from the vent.
There are four possible start-up modes:
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Standard, with operator engagement of the manifold solenoid valve;
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Semi-automatic, requiring operator’s manual engagement of the manifold solenoid valve—the EPCU will automatically disengage when purging is successfully completed;
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Fully automatic—when safe pressure is detected, the solenoid valve will engage without operator intervention and disengage on completion of purging;
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Proportional mode, which continuously controls the flow rate during and after purging.
The vent is universally mounted to an application enclosure of up to 450 ft3 (12.7 m3).
For more information call 330/486-0002 or email [email protected].
