Schneider Electric Altivar Machine ATV320 fault OCF: Overcurrent
OCF on a Schneider Altivar ATV320 is an overcurrent error: the drive detected excessive output current and tripped. Schneider lists wrong settings in the [Settings] SET- and [Motor control] DRC- menus, too much inertia or load, and mechanical locking as the probable causes.
Diagnose this with AI
Try Free Drive Diagnostic Upload a keypad photo, the fault history or a parameter export from your Schneider Electric Altivar Machine ATV320. InduQT compares the evidence and suggests the next useful checks.
When it happens
- During acceleration of a high-inertia load
- On a load step or jam while running
- At start after a motor or parameter change
Likely causes and checks
1Inertia or load too high for the ramp
- Points to it
- Trips partway through acceleration; worse with heavy loads.
- Check
- Lengthen [Acceleration] ACC and check the motor, drive and load sizes against each other.
2Mechanical locking
- Points to it
- Motor barely turns before the trip, or trips when a jam occurs at speed.
- Check
- With the drive locked out, check that the mechanism turns freely.
3Motor control parameters wrong
- Points to it
- After drive replacement, factory reset or motor change.
- Check
- Check the SET- and DRC- parameters against the motor rating plate ([Nom Motor Voltage] UNS, [Nom Motor Current] NCR) and run [Autotuning] TUN.
4Current limit or switching frequency setting
- Points to it
- Parameters are correct and the mechanism is free but OCF continues.
- Check
- Schneider’s listed remedies include decreasing [Current Limitation] CLI and increasing [Switching frequency] SFR.
Telling it apart
- SCF1 is a short or ground at the drive output and SCF3 is significant earth leakage; HDF (IGBT desaturation) is a short or ground at the drive. Check those first if the trip is instant, even unloaded.
- OCF needs a power reset unless [Extended Fault Reset] HRFC = YES, in which case the RSF input can clear it.
- SSF is a torque or current limitation error, a softer limit than OCF.
Relevant parameters
| Parameter | Name | Why it matters |
|---|---|---|
| ACC | Acceleration | 0.00 to 6,000 s; factory setting 3.0 s. |
| CLI | Current Limitation | 0 to 1.5 In; decreasing it is a listed remedy. |
| SFR | Switching frequency | 2 to 16 kHz; increasing it is a listed remedy for OCF. |
| HRFC | Extended Fault Reset | When YES, OCF, SCF1 and SCF3 can be cleared with RSF instead of a power reset. |
Evidence to collect
- Error history record (motor current, output frequency) for OCF
- ACC setting and load inertia
- DRC- motor data vs rating plate
- CLI and SFR settings
- Whether the trip was instant or partway through the ramp
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