What causes fault code CONV-007 (Conveyor Speed Deviation)?

Speed sensor (encoder/prox) failed or misaligned. Belt slipping on drive pulley — tension too low. Drive pulley lagging worn smooth — no grip on belt. VFD not reaching commanded frequency — current limit active. Gearbox slipping or damaged — input and output speeds don't match

How do I fix fault code CONV-007?

Check speed sensor: verify pulses with oscilloscope or drive display. Inspect belt tension — increase take-up if belt is slipping on drive pulley. Check drive pulley lagging — replace if smooth, worn, or delaminating. Check VFD display — if current-limited, reduce load or upsize drive. Listen to gearbox for unusual noise — check oil level and condition. Verify speed feedback scaling in PLC matches physical sensor setup

Conveyor Speed Deviation

CONV-007

Actual belt speed differs from commanded speed by more than allowable tolerance. Speed feedback doesn't match setpoint.

medium conveyor

conveyor speed encoder belt slip feedback

Probable Causes (ranked)

Speed sensor (encoder/prox) failed or misaligned
Belt slipping on drive pulley — tension too low
Drive pulley lagging worn smooth — no grip on belt
VFD not reaching commanded frequency — current limit active
Gearbox slipping or damaged — input and output speeds don't match

Fix Steps

1 Check speed sensor: verify pulses with oscilloscope or drive display
2 Inspect belt tension — increase take-up if belt is slipping on drive pulley
3 Check drive pulley lagging — replace if smooth, worn, or delaminating
4 Check VFD display — if current-limited, reduce load or upsize drive
5 Listen to gearbox for unusual noise — check oil level and condition
6 Verify speed feedback scaling in PLC matches physical sensor setup

Field Trick

Mark the belt and drive pulley with a paint pen. If the belt mark moves relative to the pulley mark, the belt is slipping — re-tension or replace lagging.

Suggested Replacement Parts

Parts matched to fault category: Encoder

Omron E6B2-CWZ6C Rotary Encoder P/N: E6B2-CWZ6C-1024P/R Incremental, 1024 PPR, 5-24VDC, NPN open collector

AutomationDirect $85.00 Amazon $75.00 Digikey $95.00

Autonics E40S8-1024-3-T-24 Encoder P/N: E40S8-1024-3-T-24 40mm body, 1024 PPR, totem pole output, 8mm shaft

AutomationDirect $65.00 Amazon $58.00

Prices are estimates. Verify part numbers match your equipment before ordering.

Need a deeper diagnosis with photo analysis and AI-powered troubleshooting?

Run Full Diagnosis