Figure 4-10. Wiring Diagram - Controlling Motors - Syn-Tech Systems FuelMaster FMU-2500 Classic Installation Manual

FuelMaster Installation Manual
®

Figure 4-10. Wiring Diagram - Controlling Motors

If the dispenser is being fed from the top of an aboveground tank, there must be an anti-siphon
valve on the tank, or inline between the dispenser and tank. Without an anti-siphon valve, the
siphon effect created when a previous transaction was performed will permit fuel to siphon
through the dispenser and pump motor to the dispenser nozzle after the pump motor is turned
off. Product may then be obtained without authorization.
If the motor is powered by 220 VAC, the second motor feed may be from another power source.
This may be evident by power being present on RESET COMPLETE when the pump handle is
turned off. When the pump handle is turned off, power from the second power source will
backfeed through the motor coil windings to RESET COMPLETE. To determine if this is
occurring, disconnect and check the second motor feed line. A 110 VAC pump motor will have
the second motor feed line connected to neutral. A 220 VAC pump motor will have the second
motor feed line connected to 110 VAC.
81