Cooling fan
Common VFD, drive, UPS, and cabinet overheating failure point.
Yaskawa P1000 Fault Codes - What They Mean
The Yaskawa P1000 is an HVAC and pump VFD used on fans, pumps, cooling towers, and building mechanical systems. Most P1000 faults come from load problems, line voltage issues, motor wiring faults, or setup parameters that no longer match the motor and driven equipment.
Common P1000 Fault Codes
| Code | Meaning | First Check |
|---|---|---|
| OC | Overcurrent | Motor cable, short circuit, jammed load |
| OV | DC bus overvoltage | Decel time, regen load, braking setup |
| UV1 | DC bus undervoltage | Incoming line voltage and fuses |
| OH | Heatsink overheat | Cooling fan, cabinet filters, ambient temp |
| LF | Output phase loss | T1/T2/T3 wiring and motor winding continuity |
| GF | Ground fault | Motor cable insulation and motor windings |
| OL1 | Motor overload | Motor FLA settings and load condition |
| OL2 | Drive overload | Drive size, current limit, duty cycle |
| PF | Input phase loss | Supply phase balance and contactor |
| CE | MEMOBUS/Modbus communication error | Network cable, node address, timeout |
Step-by-Step Fix
- Read the fault history. Use the keypad fault trace before resetting. Record output current, DC bus voltage, output frequency, and run command state.
- Check incoming voltage. For UV1, OV, or PF, measure line voltage at the drive while the load runs. Check phase balance, fuses, disconnects, and contactor poles.
- Test the output circuit. For OC, GF, or LF, power down and test the motor cable and motor separately. Do not megger through the drive terminals.
- Inspect the driven equipment. A stuck damper, seized fan bearing, clogged pump, or failed check valve can trigger OC, OL1, or OL2.
- Review acceleration and deceleration. Short acceleration ramps can trigger OC. Short deceleration ramps can trigger OV on high-inertia fans and pumps.
- Verify motor data. Check motor rated current, voltage, frequency, and overload settings against the nameplate.
- Clear the fault and test at load. Reset only after the electrical and mechanical cause is fixed.
Parameters Worth Checking
| Parameter Area | Why It Matters |
|---|---|
| Accel/decel time | Too short can cause OC or OV |
| Motor rated current | Wrong value can cause nuisance OL1 or weak protection |
| Stall prevention | Helps avoid trips during heavy acceleration or deceleration |
| Communication timeout | Controls CE behavior on building automation networks |
Need Replacement Parts?
Before ordering, match the drive part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
Call a drive technician if OC or GF appears with the motor leads disconnected. That usually means the P1000 output section or current detection circuit needs bench testing.
Source Notes
- Yaskawa P1000 technical manuals and drive support documentation.
- Yaskawa support FAQ for LF output phase loss.