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Facilities Mechanic

Guest Joe V

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Looking for help to program the LN2 delivery system operates by measuring the downstream pressure and temperature in the feed line to determine if a cylinder is feeding or empty. A cylinder is determined empty if the temperature is warmer than its setpoint and the pressure is lower than its setpoint. Note that both input conditions must be true for the switch to activate. When the active cylinder becomes empty, that cylinder’s valve closes and the valve to the next non-empty cylinder in the supply queue opens. The empty cylinder is then stored in memory with an empty flag and displayed on the screen and by a flashing indicator light. If the next cylinder in the supply queue has already been flagged empty, then that cylinder will be skipped. The controller then waits a timed delay (factory preset at two minutes, adjustable) for the new cylinder to supply the feed line. If, after the time delay, both pressure and temperature setpoints still evaluate to the empty condition, then the controller switches over to the next non-empty cylinder in the queue and again waits the timed delay. The process repeats until all connected cylinders are flagged as empty. The controller is programmed to manage two to four valves/cylinders in the supply queue, although the most common system contains three valves. Each solenoid valve is normally closed, so turning the controller off or disconnecting the power will effectively cut-off all LN2 supply to the feed line. Indicator lights are located on the control panel underneath the controller screen. There is one indicator light for each solenoid valve (or intended cylinder) numbered from left to right 1, 2, 3, and 4. An audio alarm is located on the right side of the controller and has the option of sounding when all three cylinders are empty. When a cylinder is feeding, its indicator light turns on.

When a cylinder is empty, its indicator light blinks. When a cylinder is full and not feeding, its indicator light is off. When all cylinders are empty, all three indicator lights blink and the audio alarm sounds (although the audio alarm can be deactivated). An Ethernet port is provided on the bottom of the control panel to send alerts over the

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