Drive (VFD) Disconnected Warning: Diagnosis and Recovery

What the Warning Means

When the Check screen shows a drive as Disconnected, the Retro C software is not receiving the expected response from that VFD. The most common causes are loss of drive power, an open RS-485 communication connection between the VC1 and VFD, an incorrect or faulted VFD, or a VC1 problem.

Safety

Electrical panels contain hazardous voltage. Only qualified personnel should open an enclosure, test voltage, perform continuity checks, or replace a fuse. Follow your facility’s E-STOP and lockout/tagout procedures before touching wiring or components. Never perform a continuity test on an energized circuit.

Determine the Scope First

1. Open the Check screen and record the disconnected drive number.
2. If the saw is in E-STOP, all drives are turned off for safety and will appear disconnected. Clear E-STOP only after the machine is safe and the area is clear.
3. If one drive is disconnected, continue with the checks below.
4. If all stationary and carriage VC1s and VFDs are disconnected after E-STOP is cleared, use the Countdown Timer Warning troubleshooting guide. A network-switch power or COMP_NET problem is more likely than multiple simultaneous drive failures.

1. Check Power to the VFD

1. Use the drive number shown on the Check screen to locate the corresponding VFD in the stationary or carriage enclosure.
2. Visually check whether the VFD display or power indicators are on.
3. If the VFD has no power, have a qualified person inspect the fuses and incoming power for that drive.
4. Because E-STOP removes power from the drives, fuse continuity must be checked with the circuit safely de-energized.
5. Replace a failed fuse only with the approved type and rating, then close the enclosure and restore power using the site-approved procedure.

If the drive powers on and reconnects on the Check screen, verify normal operation before returning the saw to production.

2. Check the RS-485 Communication Wiring

Communication between the VC1 and VFD normally uses two wires:

• Blue: Signal +
• White/blue: Signal −

The VC1 end normally uses ferrules. Depending on the VFD model, the drive end may use ferrules, an RJ11 connector, or an RJ45 connector.

1. Place the machine in the required safe electrical state before touching the connection.
2. Inspect the blue and white/blue wires for looseness, cuts, crushed sections, or reversed polarity.
3. Check the ferrules and terminal screws at the VC1.
4. Check the VFD connector. RJ11 plugs can vibrate partly out of the jack and cause an intermittent disconnected warning.
5. Reseat the connector fully, restore the system safely, and check the drive status again.

For terminal and wire-function details, see Common VFD Wiring to VC1s.

3. Check the VFD

• If the VFD has power, check its display for a fault or warning.
• Confirm that the installed VFD model and communication settings are correct for that drive position.
• Do not change parameters at random. Record the displayed fault and drive number, then use the model-specific Enventek procedure or contact Technical Support.
• If the warning appeared after a VFD replacement, verify that the replacement drive was programmed before operation.

4. Check the VC1

If the VFD is powered and the RS-485 wiring is secure, confirm that the VC1 has power and network communication. If several devices connected through the same VC1 are unavailable, the VC1 or its network connection is more likely than an individual VFD failure.

Verification

• The VFD is powered and shows no unresolved fault.
• The Check screen shows the correct drive as connected.
• The disconnected warning does not return after the software refreshes or restarts.
• With the area clear, the drive responds correctly during the approved functional test.

Contact Enventek If

• The replacement fuse opens again.
• The VFD repeatedly loses power or communication.
• The drive is powered and correctly wired but remains disconnected.
• A VFD or VC1 fault remains after a safe restart.

Contact Enventek Technical Support at 269-815-4150 with the drive number, VFD model, displayed fault, and the troubleshooting steps already completed.

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Escalate When

Record the exact screen message, affected component, indicator-light state, and steps already attempted. Contact Enventek Technical Support if the fault remains or the machine does not respond as expected.