Send a control word bit 07 (Reset trip) via explicit message or from the PLC. Example for Profibus: Control word = 0x0080.
For qualified technicians only – high energy stored in capacitors.
Using a multimeter in diode mode (or resistance low-ohms): danfoss error 1027
| Measurement (drive disconnected from mains, brake resistor disconnected) | Healthy Reading | Shorted IGBT Reading | |--------------------------------------------------------------------------|----------------|----------------------| | Between BR+ and BR- (some drives) or DC+ and BR terminal | Diode drop 0.3–0.8V one way, OL reverse | 0.0V or very low both ways | | Between BR- and DC- (common config) | Same as above | Short both ways |
If shorted both directions → IGBT failed. Send a control word bit 07 (Reset trip)
From the PLC or network scanner:
If the error returns immediately on power‑up or after a reset, the internal hardware is likely damaged. Common failures inside the drive include: For qualified technicians only – high energy stored
If the master resumes cyclic communication before the timeout time expires, the drive may auto-clear the alarm (depending on Parameter 8-07 Diagnosis Trigger).
The drive is configured to receive cyclic telegrams from a fieldbus master (PLC, DCS, or BMS). Parameter 8-04 Control Timeout Function defines what happens when those telegrams stop arriving. Error 1027 triggers when:
| Cause | Likelihood | Explanation | |-------|------------|-------------| | Shorted brake resistor | High | Low-ohm short (<< rated value) draws excessive current, killing the IGBT. | | Wiring short | Medium | Brake resistor cable chafed, terminal box moisture, incorrect polarity (if using DC bus braking). | | Brake resistor value too low | Medium | Resistor ohms below minimum allowed for the drive model. | | IGBT natural failure | Medium | Age, thermal cycling, poor quality power supply, or voltage spikes. | | Control board / gate drive fault | Low | Faulty gate driver keeps IGBT turned on. |
Unlikely to cause 1027, but a corrupted parameter set can mimic internal faults. Try: