GS20 ACM/DCM Common Wiring

On a Delta GS20 VFD, the brown common wire from the VC1 must connect to the ACM terminal. Install a jumper from ACM to DCM. Without this jumper, the drive may receive a speed reference but fail to respond correctly to the digital run and direction commands.

Electrical safety: De-energize and lock out the machine before opening the VFD enclosure or moving conductors. VFD capacitors retain hazardous voltage after power is removed; wait the manufacturer-specified discharge time and verify voltage before touching terminals.

Correct connection

1. Locate the brown common wire coming from the VC1 cable.
2. Connect the brown wire to the GS20 ACM terminal.
3. Install a short jumper between ACM and DCM.
4. Tug-test both connections and confirm that no loose strands can contact an adjacent terminal.

Why the jumper is required

ACM is the analog common used with the 0–10 V speed-reference signal. DCM is the digital common used by the run and direction inputs. Joining ACM and DCM gives both command circuits the common reference expected by the VC1 wiring.

Verification

• Restore power and confirm the VFD display starts normally.
• Command the movement at low speed and verify that the drive receives both the run command and the speed reference.
• Verify the commanded direction before operating at normal speed.
• If the VFD still does not run, check the run/output wiring, 0–10 V signal, VFD parameters, and displayed fault code. Do not move the brown wire to a 24 V terminal.

For help with the remaining VC1 run, direction, speed-reference, or communication wiring, contact Enventek Support with the VFD model, the displayed fault code, and a clear photo of the terminal connections.