Schneider Electric fault record

OCF: Overcurrent Fault

The Altivar drive trips on OCF at run command, during acceleration or when the load changes.

Deep search-intent fault page11 min read

Scope of this technical record

ATV61 / ATV71 OCF routing for users deciding whether overcurrent is created by load inertia, brake release, motor data, ramp settings, motor/cable fault, current sensing or output power bridge damage.

Safety boundary

Do not repeatedly reset OCF into a high-current condition. Secure the machine, isolate hazardous voltage and separate the motor/cable boundary before internal inspection.

ATV61 / ATV71 OCF route

1Start / ramp
2Motor settings
3High inertia
4Mechanical block
5Current path

OCF is first a motor-data and load timing question before internal current-path repair.

ATV61 / ATV71 OCF timing image

Schneider ATV61 ATV71 OCF overcurrent motor settings high inertia mechanical blockage route diagram
The OCF image keeps the diagnosis on motor data, ramp and load before an internal current-path conclusion.

Searcher intent coverage

OCF users need to know whether the drive hit current limit because of setup, load or a real power path issue.

Observed situationDecision neededEvidence that satisfies the search
At startMotor data or output pathNameplate/settings and insulation boundary
During accelerationHigh inertia or rampAcceleration time and load evidence
After repairDriver/output pathPrevious repair and channel evidence

What OCF users are trying to solve

An OCF search usually comes from a machine that trips at start, during acceleration, or when the load changes. Schneider public guidance points to hardware current limitation, motor parameters, high inertia, overloading or mechanical locking. The page must therefore start with the machine event, not the power board.

ATV71’s common application base—hoist, conveyor, packaging and high-inertia machinery—makes this especially important. A brake that releases late, a jammed conveyor, a heavy lift, a pump blockage or a too-short ramp can all produce a current fault while the drive is working correctly.

OCF timing map

When OCF appearsMost likely first boundaryEvidence to record
Instant at enableOutput wiring, motor cable, phase/ground fault or power bridgeMotor/cable isolation, terminal inspection, whether SCF also appears
During accelerationRamp, high inertia, brake release, motor data, load torqueAcceleration time, motor current, brake status, load condition
Only under process loadMechanical jam, overloaded machine, pump/fan blockageLoad event, current trend, mechanical inspection
After parameter workMotor nameplate mismatch, control mode, current limitOld/new parameters, motor plate photo, autotune history
After module repairDriver/current feedback/cause not correctedStatic bridge and driver evidence before another run

Field checking sequence

Record the exact trip timing first. If OCF occurs immediately at enable, stop and prove the output wiring and motor/cable boundary. If it occurs during acceleration, review load, brake release, acceleration ramp, motor data and control mode. If it occurs only during production, inspect the mechanical process before blaming the drive electronics.

When external evidence is not enough, move inward: output bridge static evidence, gate-drive path, current sensing and control-board interpretation. This inward movement should only happen after the motor/cable/load route is documented. Otherwise a replacement power board may be destroyed by the same external cause.

OCF decision table

EvidenceExternal/machine routeDrive-side route
Brake not fully releasedStrong external routeDrive may simply be responding to load
Acceleration too short for load inertiaStrong setup routePower hardware not proven
Motor data inconsistent with nameplateParameter routeBoard replacement premature
Fault clears after motor/cable isolationExternal output routeInternal fault not proven
Fault remains with external route provenExternal route weakerOutput bridge/current sense/driver route stronger

Repair request standard

A useful OCF request includes the ATV type code, application, motor data, trip timing, acceleration/deceleration settings, brake/load evidence, motor/cable insulation result and whether SCF or other codes appear. If the drive was already repaired, include what power or driver assemblies were changed and whether the original motor/cable was tested.

Do not describe the case as “OCF board fault” unless the external route has been proven. The strongest article outcome is a clear next decision: adjust ramp/load/motor data, repair motor/cable/brake, or escalate to output stage/current sensing with evidence.

OCF stop conditions

ConditionReasonNext action
Mechanical load not checkedDrive may be protecting itselfSecure and inspect machine load
Motor/cable insulation unknownExternal fault may destroy bridgeIsolate and test correctly
Brake release unknownHeld load can cause instant current riseVerify brake command and physical release
Prior module repair undocumentedRepeat failure riskCollect driver/module repair evidence

Field record checklist

  • ATV61/ATV71 type code and application
  • OCF timing: enable, acceleration, load, reversing or heat soak
  • Motor nameplate data and parameter values
  • Brake release, mechanical load and ramp settings
  • Motor/cable insulation and terminal evidence
  • Output bridge/current-sense evidence only after external route is proven

Technical basis and reference documents

This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.

Schneider Electric OCF FAQSchneider Electric

Public FAQ describes OCF as hardware current limitation and points to motor parameters, high inertia, overload and mechanical locking.

ATV61/ATV71 training materialUploaded internal reference

Used for application context and protection-family routing.

Diagnostic workflow