MDE-4567D 9820K Series AST Pumps Installation and Operation Manual · January 2020
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Operating Sequence
Operating Sequence and Locking the Nozzle
7 – Operating Sequence and Locking the Nozzle
Operating Sequence
The exact sequence of events that occurs during the operation of the pump is determined by
various switch/jumper settings, inputs, and the user. A typical transaction is explained below.
1
Turn on the pump handle.
If AC is present on the Pump Motor Feed line, the reset cycle begins.
The display does the following:
• Goes blank for one second
• Shows all 8s for one second
• Goes to 0.000 (gallons) or 0.00 (liters) and remains this way for one second
The Pump Motor turns on. The Slow Flow valve turns on.
2
The user begins to dispense fuel.
Quantity will not be recorded on the display until 0.010 gallons (0.04 liters) is reached.
However, all pulses will be sent out on the Pulse Output line, if equipped. At 0.010 gallons
(0.04 liters), the Fast Flow valve turns on.
The pump continues to run until one of the following conditions occurs:
Note: These conditions turn off all relays.
• The handle is turned off.
• The Pump Motor Feed line is turned off.
• A pulser error is detected.
• A timeout of 255 seconds is reached. If connected to a fuel management system, the
timeout loaded into the system will be used.
• A quantity of 990.000 gallons (9900.00 liters) is reached. If connected to a fuel
management system, the limit set in the system will be used.
• The pump is halted by an operator of a fuel management system.
• An AC power failure occurs.
The 9820K continues to monitor for pulses until a 2-second period with no pulses occurs. At
that, time the transaction is considered completed.