Control Lines
Pump Motor Feed
Page 20 MDE-4567D 9820K Series AST Pumps Installation and Operation Manual · January 2020
Pump Motor Feed
Model 9820K
The Pump Motor Feed is a 115 VAC (230 VAC International) input which is required to power
the pump and authorize the control line. This line is used to provide authorization for the unit
(when enabled through the Dual In-line Package (DIP) switches). The Pump Motor Feed
supplies power to the electric motor as well as the valves. The gauge of this wire (and its
neutral wire) should be determined according to the size of the motor, the voltage at which the
motor will be powered (115 VAC or 230 VAC), and the distance from the breaker panel to the
pump. It however does not supply power to the motor for 3-Phase motors. Separate wiring is
required for 3-Phase motors. Pump Motor Feed wires must not be used to supply the Micro
Neutral/Feed.
If the line to the Model 9820K is controlled by a fuel management system using solid state
relays, a resistor assembly must be installed between the Pump Motor Feed line and Neutral
Feed to prevent false triggering of the authorization input. The resistor assembly is 8.2K Ohm,
10 Watt (P/N C05818) for 115/230 VAC domestic and 30K Ohm, 10 Watt (P/N C06683) for
230 VAC international wiring.
Neutral Feed
The Neutral Feed is the AC current return line back to the breaker panel for all attached
devices. The gauge of this wire should be equal to that of the Pump Motor Feed. Together with
the pump feed, it supplies power to the motor and valves.