Danfoss Error 1027 -

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:

If the error returns immediately on power‑up or after a reset, the internal hardware is likely damaged. Common failures inside the drive include:

Follow this field-tested workflow. It assumes you have a multimeter, a laptop with Danfoss MCT-10 or VACON® NCDrive, and physical access to the drive.

Disclaimer: This document is for informational purposes only. Always refer to the specific Danfoss VLT Operating Instructions (MG.33.BX.XX) relevant to your specific firmware version for authoritative technical data.

In the context of Danfoss VLT drives, Error 1027 primarily indicates a communication or hardware failure

related to internal messaging, specifically suggesting that a CAN telegram cannot be sent. On some specific models like the , it can also manifest as an overvoltage fault Likely Causes Internal Communication Failure

: The drive is unable to send a CAN telegram, which often points to a potential hardware malfunction within the internal circuitry. Mains Overvoltage

: High incoming voltage from the power supply that exceeds the drive's safe operating limits. Regenerative Energy

: Energy being fed back into the drive's DC bus from the motor (common during rapid deceleration of high-inertia loads) faster than the drive can dissipate it. Recommended Troubleshooting Steps Check Power Supply

: Measure the incoming AC line voltage to ensure it is stable and within the specified nominal range (typically within ±10%). Inspect Wiring and Connections

: Check for loose or damaged wiring between the control card and power card, as internal communication errors can stem from poor physical connections. Basic Reset Disconnect the motor from the drive.

Power down the unit and wait for the display to turn off completely to allow capacitors to discharge. Power the unit back on and press the button on the Local Control Panel (LCP). Extend Deceleration Time

: If the error occurs during motor braking, try increasing the ramp-down time to reduce regenerative voltage spikes. Manual Initialization

: If the fault persists, you may need to perform a factory reset by holding [Main Menu] simultaneously while powering up the drive.

If these steps do not clear the error, it typically indicates a permanent hardware failure

(such as a faulty control or power card), and you should contact Danfoss Technical Support parameter codes for adjusting deceleration times or instructions for a full hardware factory reset Common Danfoss VFD Alarms – Codes, Causes, and Action

Troubleshooting Danfoss Error 1027: A Quick Guide If you're staring at your Danfoss VLT display and see Error 1027, you likely have a hardware communication or power board issue. Unlike common user-fixable alarms, Error 1027 is often a "deep-level" fault indicating that the drive's internal systems aren't talking to each other correctly. What is Danfoss Error 1027?

In most Danfoss VLT documentation, such as the IBA Lift technical guide, Error 1027 is classified as a CAN telegram error or a hardware interface fault. Specifically:

Communication Breakdown: The drive's internal processors cannot send or receive data packets (telegrams) reliably.

Hardware Failure: It often points to a physical fault on the power card or the control card interface. Immediate Troubleshooting Steps

Before calling for service, you can try these basic resets to see if the error was a one-time glitch:

Power Cycle: Turn off the main AC power to the drive. Wait for the display to go completely blank (discharging the capacitors) before restoring power.

Factory Reset: If you can still access the menu, you can perform an "Initialization" by following the steps on Danfoss MyDrive Assistant to return the drive to factory defaults.

Check External Connections: 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 danfoss error 1027

If the error persists after a reset, the issue is likely internal. Technicians often look for:

Faulty Control Cards: The brain of the VFD may need replacement.

Power Board Issues: On older models like the Danfoss VLT 3000 Series, internal voltage irregularities can cause the processor to "lock up" and throw interface errors.

EEPROM Errors: Sometimes the drive's internal memory (where parameters are stored) becomes corrupted, preventing the boot-up sequence from completing. When to Call Professional Support

Error 1027 is rarely a "loose wire" fix. If a power cycle doesn't clear it, it usually requires a component-level repair or a board replacement.

Experts at JustAnswer: For immediate advice from an HVAC specialist, you can consult the JustAnswer platform to see if others have resolved similar 1000-series codes.

Official Documentation: Refer to the Danfoss Quick Troubleshooting Guide for instructions on how to pull the full alarm log, which will provide more context for a service technician.

Pro Tip: If you're using a Solis inverter that shows the same code, check the Solis Service Center for specific instructions on checking DC-side polarities and MC4 connectors.

In Danfoss systems, Error 1027 typically indicates a CAN telegram communication failure.

Specifically, this error appears when a CAN telegram cannot be sent, which often points toward a possible hardware error within the communication interface. Understanding Error 1027

According to documentation for systems like the Danfoss VLT LD 302, error codes in the 1024–1279 range are related to CAN communication issues.

Cause: The controller is unable to transmit data over the CAN bus.

Hardware Component: This frequently involves the communication card or the physical wiring of the CAN network. Recommended Troubleshooting Steps

If you are seeing this error, you can attempt the following diagnostic steps:

Check Physical Connections: Inspect the CAN bus wiring for any loose connections, shorts, or damaged shielding.

Verify Hardware: Since the error notes a "possible hardware error," check if the communication module is properly seated in the drive.

Perform a Reset: You can attempt to clear the fault by pressing the [Reset] key on the LCP (Local Control Panel).

Power Cycle: Disconnect the mains supply and wait for the display to turn off completely before reconnecting.

Initialization: If the error persists, a Manual Initialization to default settings may be necessary, though this will erase custom parameter settings.

Process: Hold [Status, Main Menu], and [OK] simultaneously while powering up the drive. Danfoss VLT LD 302 HDR-V2 - IBA Lift

Error 1027 on a Danfoss drive typically points to a communication or internal hardware failure, specifically related to the CAN telegram or the DC interface.

Depending on your specific Danfoss model, this code can indicate several distinct issues: ⚠️ Common Causes

CAN Telegram Failure: In high-performance or lift-specific drives (like the VLT LD 302), error codes in the 1024–1279 range signify that a CAN telegram cannot be sent. The drive is configured to receive cyclic telegrams

DC Interface Issues: In some inverter systems, 1027 is a "DC-INTF" alarm, often triggered by loose connections or polarity issues on the DC side.

Hardware Component Failure: It can be a "General Hardware Error" where the internal control board cannot communicate with the power card or external options.

Voltage Limit Breach: Some HVAC-specific drives (FC 102) may display this for high-voltage conditions exceeding safe operational limits. 🛠️ Troubleshooting Steps Check Physical Connections:

Inspect any serial communication or Fieldbus cables for damage or loose seats.

If using an inverter, verify all DC connectors (like MC4) are properly crimped and polarity is correct. Verify DC Bus Voltage:

Check the DC bus voltage using the drive's display or a multimeter. It should generally be 1.35 times your incoming AC voltage. Perform a Power Cycle: Turn off the mains supply.

Wait for the display to go completely dark (allowing capacitors to discharge). Power back on to see if the internal communication resets. Reset the Drive:

Try a manual reset by pressing the [Off/Reset] button on the keypad.

If the fault persists, you may need a Factory Reset (Parameter 14-22), but be aware this erases all custom settings. Swap Control Cards:

If you have a twin unit, try swapping the control card to see if the error follows the card (indicating a hardware failure).

💡 Key Takeaway: If the error reappears immediately after a reset and power cycle, it is likely a severe hardware fault. You should contact Danfoss technical support or your local supplier for a potential board replacement. If you'd like to troubleshoot further, tell me: The exact model number (e.g., FC 102, FC 302, VLT Micro).

What the drive was doing (starting, running, or idling) when the error occurred. Danfoss VLT LD 302 HDR-V2 - IBA Lift

On a Danfoss VLT drive, "Error 1027" (or Alarm 1027) typically indicates an overvoltage fault. This occurs when the voltage entering the drive or the internal DC bus voltage exceeds safe operational limits, often leading to an immediate trip to protect internal components.  🛠️ Common Causes & Fixes 

The most frequent reasons for this error include external power fluctuations or internal motor-related issues: 

Excessive Supply Voltage: The incoming line voltage is higher than the drive's rated capacity.

Fix: Use a multimeter to verify the mains voltage is within the range specified on the drive's nameplate.

Regenerative Energy: The motor is acting like a generator (e.g., during a quick deceleration of a high-inertia load), pushing power back into the drive and spiking the DC link voltage.

Fix: Increase the deceleration ramp-down time (Parameters 3-42 or 3-52) or activate "Overvoltage Control".

External Interlock Issues: In some Danfoss configurations, a missing 24V signal on a terminal programmed as an "External Interlock" can trigger similar "Stop/Trip" behaviors.

Fix: Check for continuity on programmed digital input terminals (often terminal 27) and ensure 24V DC is present.  📋 Step-by-Step Troubleshooting 

If you encounter this error, follow these steps to clear it: 

Safety First: Disconnect the drive from AC mains and wait for the DC capacitors to discharge (refer to manual for discharge time).

Isolate the Motor: Disconnect the motor cables from the drive. Disclaimer: This document is for informational purposes only

Power Up & Reset: Restore power to the drive without the motor connected and press the [Reset] key.

Test Run: Attempt to run the VFD with no load. If the fault does not reappear, the issue is likely with the motor's deceleration settings or the load itself.

Manual Initialization: If the error persists and prevents access, perform a "Manual Initialization" by holding [Status] + [Main Menu] + [OK] while powering up (for LCP 102) to restore factory defaults. 

For a visual guide on diagnosing control card faults which can lead to various error codes, watch this repair walkthrough: 00:19

Professional Service: Contact an authorized Danfoss Service Partner or supplier to verify if the drive's internal components have failed. Top ten VFD tech support calls - Danfoss

Error 1027 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.

Common aliases on display:
Brake IGBT fault / Mains phase loss (if misdiagnosed) / Alarm 27 (some legacy models)

⚠️ This is a serious hardware fault. Do not simply clear the alarm and restart without investigation.

Error Code: 1027 Manufacturer: Danfoss Product Line: VLT AutomationDrive (FC 302) and related VLT series Category: Serial Communication Fault Severity: Warning / Alarm (Configurable)

Error 1027 on a Danfoss VLT drive indicates a Fieldbus/Serial Communication Fault. Specifically, this error signals that the drive has detected a timeout or a loss of communication on the serial communication bus (typically the RS-485 port or an installed Fieldbus option card).

When this error is triggered, the drive signals that it has stopped receiving valid telegrams (data packets) from the master controller (PLC or SCADA system) within a predetermined time window.