Recover Retro C After an Unexpected Power Loss

Use this guide after a facility outage, opened main disconnect, tripped circuit, or other unexpected loss of power—especially when the saw was moving. The purpose is to restore operation without hiding a control-power, communication, or calibration problem.

Applicability

Field	Detail
Product	Retro C
Subsystem	Computer startup, VC1 control power, network communications, and positioning
Hardware generation	All Retro C generations
Skill level	Operator for screen checks; maintenance or qualified electrical technician for fault investigation
Lockout/tagout	Required before panel, wiring, encoder, or mechanical inspection
Estimated time	15–30 minutes when no damage or persistent fault is present
Tools or parts	Accurate measuring tool and facility-approved lockout devices

Before You Begin

Confirm that facility power is stable and that no person is inside the guarded area. Do not repeatedly cycle power to clear warnings. If a breaker, fuse, or protection device opens again, stop and have a qualified electrical technician identify the cause.

Record whether the saw was stationary or moving when power was lost. A power interruption during movement creates a greater chance that a displayed position no longer matches the mechanism.

Recovery Procedure

1. Inspect before restoring operation

From outside the guarded area, look for trapped lumber, fallen scrap, a shifted workpiece, an active emergency-stop device, or visible damage. Follow the facility lockout/tagout procedure before removing material or entering the guarded area.

Do not command movement until the travel path is clear.

2. Restore power once

Use the normal approved startup sequence. Allow the touchscreen computer, network switches, VC1s, and drives adequate time to start. Do not interrupt the boot sequence because the screen appears unchanged for a short period.

If the touchscreen remains dark, use Retro C Touchscreen Is Black or Will Not Start.

3. Record startup messages

Before pressing Clear Fault, record:

• Emergency Stop or safety-loop indications.
• Countdown Timer warnings.
• Disconnected VC1s, drives, encoders, or network devices.
• Any stall, overrun, or calibration message.
• Which end or movement is affected.

If the machine will not enable, use Retro C Will Not Start or Enable After Power-Up.

4. Confirm control devices reconnect

Check that the expected VC1s, VFDs, and encoders return online.

• If all devices remain disconnected with a Countdown Timer warning, use Countdown Timer Warning with All VC1s and VFDs Disconnected.
• If one end of the saw remains offline, use 24 V Power System: Operation and Short-Circuit Diagnosis and Troubleshooting Network Issues.
• If one drive remains disconnected, use Drive (VFD) Disconnected Warning: Diagnosis and Recovery.

The optional 24 V UPS can maintain VC1 control power during an interruption, but its presence does not eliminate the need to verify the displayed position after power loss during movement.

5. Verify position before automatic operation

If the saw was moving when power was lost, compare the displayed position with the physical position using the approved reference for each affected movement. Prioritize the carriage, material feed, angles, centerlines, and any movement that was active.

Do not run a full calibration automatically. If a movement repeats consistently but its displayed value is wrong, calibrate only that movement. If it does not return consistently, diagnose mechanical slip or encoder feedback first using Retro C Calibration Will Not Hold or Changes After Restart.

6. Perform controlled movement checks

With the work area clear, test affected movements individually in the approved manual or maintenance mode. Confirm:

• Movement begins and stops normally.
• Physical direction and displayed count direction agree.
• No axis contacts a mechanical stop.
• The same command returns to the same measured position.
• No drive, encoder, communication, or safety warning returns.

Stop immediately if a mechanism moves unexpectedly or the displayed position changes incorrectly.

7. Run a controlled verification

After the startup and position checks pass, run the site’s approved verification cut or measurement before returning to production. Inspect the result against the approved tolerance.

What Correct Looks Like

• The touchscreen and Retro C software complete startup normally.
• Emergency Stop and Countdown Timer warnings are clear.
• Expected VC1s, VFDs, encoders, and network devices show connected.
• Displayed and physical positions agree.
• Affected axes repeat correctly without stall, overrun, or encoder warnings.
• The verification cut or measurement meets the approved tolerance.

When to Contact Enventek

Contact Enventek Technical Support if several positions changed, control power repeatedly drops, devices fail to reconnect, calibration values will not remain saved, or any movement behaves unpredictably. Provide the outage time, whether the machine was moving, exact startup messages, disconnected-device list, and verification measurements.

Search Terms

power outage, power loss recovery, saw wrong after outage, machine won’t restart, lost calibration after power loss, all drives disconnected after outage