If the error 1027 persists after cycling power and checking connections, it is highly likely that the or the internal communication interface is defective. In this case, the drive will require repair or replacement by a qualified Danfoss technician.
Here is a short story looking at this error through the eyes of a technician. The Ghost in the Machine: A "1027" Story
For (MCA 104): Red “Mod” LED means network timeout.
If the error persists, try resetting the drive's parameters to factory defaults. This can clear any corrupted user settings that might be contributing to the issue. Consult your specific drive's manual for the precise procedure, but it is often done via a parameter in the "Reset" menu.
To fully appreciate the severity of Error 1027, it's helpful to understand what a CAN telegram is. In industrial automation, the CAN protocol is a robust communication standard that allows different electronic devices, like sensors and controllers, to communicate with each other without a host computer. In the context of a Danfoss VFD, CAN bus is often used to send control commands (like start/stop, speed reference) and receive status information. danfoss error 1027
Wait at least 5 to 10 minutes for the internal DC bus capacitors to fully discharge.
This means that while the problem originates from a CAN communication failure, it is often a symptom of a deeper hardware malfunction within the drive itself, rather than just a loose cable.
After the previous steps, the cause will likely be isolated to one of three areas:
is a specialized internal hardware or communication fault typically tied to a critical internal sub-code within a broad Alarm 38 (Internal Error) event . It signals that an internal sub-system—most commonly the internal CAN (Controller Area Network) serial communication bus or memory register—is unable to safely transmit telegram data across the internal circuit boards. If the error 1027 persists after cycling power
Access parameters via the LCP panel or MCT-10. Verify:
Danfoss drives (including the popular VLT® HVAC Drive, VLT® AutomationDrive, and VACON® series) rely on robust fieldbus communication for speed reference, start/stop commands, and feedback. When Error 1027 appears, the drive is essentially saying, "I cannot hear the master controller." Ignoring this fault can shut down a production line, freeze a chiller plant, or halt a conveyor system.
The power card, which manages the high-power sections of the drive, must communicate reliably with the control card. A malfunction on the power card can corrupt data on the internal bus. Furthermore, the physical ribbon cable that connects the control card and the power card can sometimes become loose, have a bad contact, or be damaged. A faulty connection here can mimic the symptoms of a full hardware failure.
Before diving into a teardown, document the exact context of the failure (e.g., was the drive running, starting up, or idle?). Then, attempt a hard reset: The Ghost in the Machine: A "1027" Story
Here’s an interesting story about “Danfoss error 1027.”
The internal CAN transceiver on the control card is damaged. The control board must be replaced by a certified Danfoss Service Partner .
indicates a short-circuit in the brake IGBT (Insulated Gate Bipolar Transistor). The drive’s software detects that the brake chopper transistor is stuck in a conductive state (failed "on") or has a direct short between collector and emitter.
