LVDD System

LVDD is the low-voltage side of the dispenser pair. It handles data, card reader, video, and communication disconnect paths.

Actual LVDD module
Actual LVDD module
Low-voltage disconnect • data • card reader • video

LVDD Controls

The LVDD, or Low Voltage Dispenser Disconnect, is a series device that breaks low-voltage circuitry such as intercom, POS, CAT5/CAT6, and related communication paths.

The LVDD gets its power from the DMEX module, providing a single-point disconnecting means for the individual MPD.

Compliance: Ensure your facility stays compliant and meets NEC 514 (13) provisions for maintenance and service of dispensing equipment.

  • 1 LVDD module per dispenser
  • 1 LVDD motherboard supports up to 4 LVDD modules
  • Start here for card reader, video, data, and communication issues
Actual LVDD module

Actual LVDD module

The LVDD is the low-voltage side of the dispenser pair and should be the first troubleshooting point for communication-related service calls.

Typical LVDD electrical scheme

Typical LVDD electrical scheme

This diagram illustrates the LVDD inside the electrical panel with low-voltage circuits routed through it while 120V dispenser power is supplied separately.

LVDD wiring diagram

LVDD wiring diagram

Use this wiring view when tracing dispenser data, card reader, auxiliary, ethernet, and low-voltage disconnect paths.

LVDD module labeled callouts

LVDD board callouts

Quick visual identification of common input, output, relay, and connector areas on the LVDD module.

LVDD quick checks

  • Confirm the correct dispenser number first
  • Identify the LVDD motherboard group (4 modules per motherboard)
  • Check input / output low-voltage routing
  • Inspect communication paths for card reader, video, and POS
  • Check module-to-motherboard connection integrity

Reference documents