DMEX Module

DMEX is the 120V control side of the dispenser pair. It handles enable, hook signal, shutdown, reset, and pump request output.

Actual DMEX module
Actual DMEX module
120V control • phase isolation • pump request

DMEX Fueling Controls

There is (1) DMEX fueling module allocated per multi-product dispenser. The DMEX module eliminates the need for a switch-neutral breaker, freeing up space inside the electrical interior. It provides phase isolation and individual dispenser disconnect means.

Also included are pump contactors used to control the submersible pumps and provide E-stop functionality. Pump contactors interface with standard or variable-speed configurations.

Compliance: Ensure your facility stays compliant and meets NEC 514 (11) circuit disconnect requirements.

  • 1 DMEX module per dispenser
  • Start here for 120V control, reset, and pump-request issues
  • Works alongside the LVDD module for the same dispenser
Actual DMEX module

Actual DMEX module

Use the DMEX module as the first troubleshooting point for fueling enable, pump request, reset, and E-stop logic.

Typical DMEX control architecture diagram

Typical DMEX control architecture

One DMEX module is allocated per multi-product dispenser. The DMEX interfaces with remote emergency shutdown, cashier control, tank monitoring, product select signals, and pump contactors.

Complete system terminal strip wiring diagram

Complete system terminal strip wiring

Use this view to trace dispenser signals, pump outputs, shutdown logic, and terminal-strip connections across the system.

DMEX module labeled callouts

DMEX board callouts

Quick visual identification of common field-service areas on the DMEX module.

DMEX quick checks

  • Confirm the correct dispenser number first
  • Check control power and terminal connections
  • Verify hook signal changes when nozzle state changes
  • Check shutdown / reset logic before moving to field wiring
  • Trace relay output to the pump contactor

Reference documents