Posts

All the articles I've posted.

• Danfoss FC302 Alarm 51 - Causes & Fix

  4 Jun, 2026

  Alarm 51 on Danfoss FC302 means AMA motor data check failed. Fix: verify motor voltage, current, power in parameters 1-20 to 1-25.

• Danfoss FC302 Alarm 50 - Causes & Fix

  4 Jun, 2026

  Alarm 50 on a Danfoss FC302 VFD means AMA calibration failed. Usually caused by incorrect motor data or wiring problems.

• Danfoss FC302 Alarm 49 - Causes & Fix

  4 Jun, 2026

  Alarm 49 on a Danfoss FC302 VFD means the motor speed is outside configured limits. Adjust parameters 4-11 and 4-13 to fix it.

• Danfoss FC302 Alarm 36 - Causes & Fix

  4 Jun, 2026

  Alarm 36 on a Danfoss FC302 VFD means mains failure or loss of supply voltage. Check input fuses and incoming power connections first.

• Danfoss FC302 ALARM 35 - Causes & Fix

  4 Jun, 2026

  ALARM 35 on a Danfoss FC302 VFD signals an option module fault. Most often fixed by reseating or replacing the option card.

• Danfoss FC302 Alarm 32 - Causes & Fix

  4 Jun, 2026

  Alarm 32 on the Danfoss FC302 VFD means motor phase W is missing. Check wiring and connections on the W output phase first.

• Danfoss FC302 VFD Alarm 29 - Causes & Fix

  4 Jun, 2026

  Alarm 29 means heatsink over-temperature. Most common fix: clean blocked air vents, replace failed cooling fans, or clear dust from fins.

• Danfoss FC302 VFD Alarm 28 - Causes & Fix

  4 Jun, 2026

  Alarm 28 means brake resistor not connected or failed. Check parameter 2-15, inspect wiring, and test resistor continuity.

• Danfoss FC302 Alarm 27 - Causes & Fix

  4 Jun, 2026

  Alarm 27 on Danfoss FC302 VFD signals a brake chopper or brake IGBT fault. Check brake resistor wiring and replace if shorted.

• Danfoss FC302 ALARM 24 - Causes & Fix

  4 Jun, 2026

  ALARM 24 on a Danfoss FC302 VFD means external fan fault. The drive detected the cooling fan stopped, is wired wrong, or airflow is blocked.

• Danfoss FC302 Alarm 48 - Causes & Fix

  3 Jun, 2026

  Alarm 48 on Danfoss FC302 means the 1.8 V control-card supply is out of spec. Most often a defective control card is the fix.

• Danfoss FC302 Alarm 47 - Causes & Fix

  3 Jun, 2026

  Alarm 47 on Danfoss FC302 VFD means 24V control supply is low. Most often caused by overloaded or shorted control wiring on terminal 50.

• Danfoss FC302 VFD Alarm 46 - Causes & Fix

  3 Jun, 2026

  Alarm 46 means power card supply voltage is out of range. Most often caused by a defective heat sink fan or clogged filters.

• Danfoss FC302 ALARM 45 - Causes & Fix

  3 Jun, 2026

  ALARM 45 on Danfoss FC302 VFD means Earth fault 2/Ground fault detected. Most often caused by motor cable insulation breakdown.

• Danfoss FC302 VFD Alarm 44 - Causes & Fix

  3 Jun, 2026

  Alarm 44 on a Danfoss FC302 VFD means earth (ground) fault. The drive detected leakage current to ground. Usually the motor or cable.

• Danfoss FC302 Alarm 43 - Causes & Fix

  3 Jun, 2026

  Alarm 43 means an external fault or interlock signal is active. Check E-stop, safety contacts, and control wiring first.

• Danfoss FC302 Alarm 42 - Causes & Fix

  3 Jun, 2026

  Alarm 42 on Danfoss FC302 VFD means overload on digital output terminal X30/6 or X30/7. Check wiring and load on these terminals.

• Danfoss FC302 VFD Alarm 41 - Causes & Fix

  3 Jun, 2026

  Alarm 41 means overload on digital output terminal 29. Disconnect the load from terminal 29, check for shorts, and verify parameters.

• Danfoss FC302 Alarm 40 - Causes & Fix

  3 Jun, 2026

  Alarm 40 on a Danfoss FC302 is a digital output overload on terminal 27. Check for shorts or excessive load on that terminal.

• Danfoss FC302 VFD ALARM 39 - Causes & Fix

  3 Jun, 2026

  ALARM 39 on Danfoss FC302 means no feedback from heat sink sensor. Check ribbon cable between power card and gate-drive card first.

• Danfoss FC302 VFD Alarm 38 - Causes & Fix

  3 Jun, 2026

  Alarm 38 on a Danfoss FC302 is an internal fault caused by a control-to-power card communication error. Reseat boards first.

• Danfoss FC302 VFD Alarm 37 - Causes & Fix

  3 Jun, 2026

  Alarm 37 on a Danfoss FC302 means phase imbalance. Check and replace blown fuses or fix loose input wiring first.

• Danfoss FC302 Alarm 34 - Causes & Fix

  3 Jun, 2026

  Alarm 34 on a Danfoss FC302 VFD means fieldbus communication fault. Check the option card installation, wiring, and network settings.

• Danfoss FC302 VFD Alarm 33 - Causes & Fix

  3 Jun, 2026

  Alarm 33 means inrush fault from too many power-ups. Let the drive cool, check for rapid power cycling, and reset once.