is an internal fault code triggered on variable frequency drives (VFDs) like the Danfoss VLT AutomationDrive FC 302 when an internal communication link fails. Specifically, this code indicates a hardware or firmware breakdown where the CAN telegram cannot be sent , trapping the control card in a permanent communication timeout.

Stay safe – never troubleshoot inside a live drive.

Verify the polarity of all DC strings connected to the inverter. Measure the Voc (Open Circuit Voltage)

Pinched, nicked, or corroded wires break data continuity. 2. Power Supply Disruptions

: Defective EEPROM data on either the power card or the control card.

Here is what it means and how you can get your system back online. What Does Danfoss Error 1027 Mean?

Reconnect power and check if the error clears. If it recurs immediately, the fault is likely permanent hardware damage. Verify Digital Inputs (VFDs) Check if any digital input is programmed as an External Interlock

To resolve error 1027, follow these step-by-step troubleshooting steps:

This will wipe all custom parameters, so back them up first.

Software corruption, though less common than hardware failure, can sometimes manifest as communication errors. Perform a parameter initialization (also known as a "master reset") to return the drive to its factory default settings. Be sure to record all your application-specific parameters first, as this process will erase them. The procedure varies slightly by model but is typically found in parameter group 14-22 or similar and set to value 2 "Initialization."

Severe electrical events, such as localized overvoltage spikes or high-frequency electromagnetic interference (EMI), can disrupt internal data packets. Over time, physical component degradation on the control card or dried-up capacitors can corrupt low-voltage signaling lines, resulting in a persistent hardware fault. Step-by-Step Diagnostic and Resolution Guide

Check if the controller is actively looking for the correct number of modules. If a module was permanently removed, change the configuration settings to "Not Selected" or "None" to stop the controller from looking for it. Step 6: Test for Hardware Faults

: Aged capacitors or failing logic gates on the control card. Step-by-Step Diagnostic Process

: The internal CAN bus communicates via low-voltage differential signals. If the motor cables are unshielded, or if the drive enclosure is inadequately grounded, high-frequency voltage spikes (

The root causes for Error 1027 can be broken down into two main categories: those stemming from the CAN bus network and those pointing to internal hardware. Understanding the difference is key to an effective diagnosis.

[ Control Card ] <--- (CAN Telegram Failed / Error 1027) ---> [ Power Card ]

The drive will usually trip and stop the motor, requiring a power cycle or reset. Primary Causes of Error 1027

: Disconnect AC power completely and wait at least 15 minutes for the DC bus to fully discharge. Isolate the Motor

Ensure that any external communication cables (like RS485 or CANbus) aren't shorted or loosely connected, as interference here can sometimes trigger internal communication alarms. Advanced Diagnosis