Danfoss Error 1027 -

From the PLC or network scanner:

Disconnect the motor leads (at the drive output). Run the drive without a load.

| Situation | Action | |-----------|--------| | Drive is under warranty | Contact Danfoss or your distributor for a replacement. | | Out of warranty, small drive (<7.5 kW) | Replace the drive (repair cost often exceeds new price). | | Out of warranty, large drive (>7.5 kW) | Contact a Danfoss authorized service center for an evaluation. |

Danfoss Error 1027 is not a death sentence for your drive. It is a logical, predictable response to a broken conversation between the master and the slave. By methodically checking cables, terminators, PLC status, and drive parameters, you can typically resolve the fault in under 30 minutes.

The key takeaways for any technician or engineer:

If you have a persistent Error 1027 that resists these steps, contact Danfoss Technical Support with your drive’s type code (e.g., FC-102P7K5T2E20H1) and the option card’s part number. They can perform advanced diagnostics using the VLT® Service Tool.

Last updated: October 2025. For the latest firmware and fieldbus manuals, visit the official Danfoss Knowledge Hub.

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Danfoss Error 1027 typically categorized as an internal hardware error overvoltage fault

, depending on the specific product line. It generally indicates that the device has detected a condition outside its safe operational parameters that it cannot self-correct. Common Meanings and Causes Internal Hardware Error

: In many Danfoss VFDs (Variable Frequency Drives), such as the VLT LD 302

, code 1027 signifies a possible hardware failure or a communication telegram that cannot be sent. Overvoltage Fault : For specific series like the , this error often points to an overvoltage condition , meaning the incoming voltage exceeds safe limits. Communication Timeout

: In some configurations, it may indicate a timeout or failure in the digital signal processor (DSP) or internal memory (EEPROM). JustAnswer Recommended Troubleshooting Steps

If you encounter this error, follow these steps to diagnose and potentially resolve the issue: Verify Input Power

: Check the incoming voltage to ensure it matches the drive's specifications. High fluctuations in the main supply can trigger overvoltage alarms. Power Cycle (Reset) Disconnect the motor from the drive.

Disconnect the mains supply and wait for the display to turn off completely.

Reconnect the power and attempt to clear the alarm using the Check for Hardware Obstructions

: Inspect the drive's heat sink for dust or debris and ensure there is adequate airflow for cooling. Factory Reset (Hard Reset)

: If the error persists, you may need to perform a "3-finger reset" by holding while powering up the drive. Note: This will erase custom settings. JustAnswer When to Contact Support If the error code

remains after a hard reset, it usually indicates a permanent internal component failure. In this case, you should contact a Danfoss Service Partner for repair or replacement. parameter settings

for a particular Danfoss model to help with the reconfiguration?

If you work with industrial automation or commercial HVAC, you have likely seen the green display of a Danfoss drive flash an alarming code: Alarm 1027. Unlike simple overvoltage or overcurrent faults, Error 1027 points to something more elusive: the communication network.

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.

This article provides a deep technical dive into Danfoss Error 1027. We will cover what it means, its common causes, step-by-step diagnostic procedures, and both field-level and long-term solutions. danfoss error 1027

| Parameter | Setting | |-----------|---------| | 2-10 Brake Function | [1] Resistor brake | | 2-12 Brake Power Limit (kW) | Match resistor rating | | 2-13 Brake Power Monitoring | [2] Trip | | 2-15 Brake Check | [1] Enable (tests at power-up) | | 2-16 AC Brake Max Current | N/A if using resistor brake |

Final note: Error 1027 is almost always a hardware replacement situation. Do not attempt to run the drive without braking if your application requires rapid deceleration or has overhauling loads.

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

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). From the PLC or network scanner: Disconnect the

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

Danfoss Error 1027 is a critical internal communication fault that typically occurs within the VLT series frequency converters (such as the FC 102, FC 202, and FC 302). It indicates that the control card is unable to communicate with the power card or that an internal CAN telegram cannot be sent. What Causes Error 1027?

This error is almost always hardware-related rather than a programming mistake. The most common reasons include:

Hardware Failure: A physical defect in the communication bridge between the control card and the power card.

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

Faulty Spare Part: Using an incorrect or incompatible spare part during a previous repair.

Firmware Mismatch: A version mismatch between the installed control card and the drive's power card. Step-by-Step Troubleshooting Guide

Because Error 1027 is an internal fault, manual intervention is often limited. However, you can follow these steps to verify if the drive can be recovered: Perform a Power Cycle Disconnect the mains supply.

Wait until the LCP (Local Control Panel) display turns off completely. Reconnect the power and see if the error clears. Attempt a Manual Initialization (Reset to Defaults) Disconnect mains power and wait for the display to go dark.

Press and hold the [Status], [Main Menu], and [OK] keys simultaneously.

Apply power while holding these keys for at least 5 seconds. Note: This will erase all your custom parameters. Inspect Internal Connections

If you are qualified to open the drive, check the ribbon cables or connectors that link the control card to the power card. A loose connection can trigger communication errors. Test the Control Card

If you have a similar, working Danfoss VLT drive nearby, swap the control card to see if the error follows the card or stays with the drive. When to Contact Support

If the error persists after a power cycle and manual initialization, it is highly likely that a hardware replacement is required.

Internal Repair: A report value of 1027 often necessitates a new power card or control card.

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

Danfoss Error Code 1027: Technical Fault Report In Danfoss VLT drives (such as the Error Code 1027 typically indicates a specific category of Internal Fault

that prevents the drive from starting or operating correctly Fault Description Error Type : Internal Error / System Fault. Common Trigger

: This code often appears when the drive's internal control system detects a hardware mismatch or a software-level failure that it cannot automatically resolve. Secondary Context

: In some troubleshooting contexts, a fault in this range may be associated with overvoltage conditions where the incoming supply exceeds safe operational limits. JustAnswer Immediate Troubleshooting Steps Power Cycle

: Disconnect the mains supply completely and wait for the display to turn off (allow at least 5–15 minutes for DC link capacitors to discharge) before reconnecting power. Verify Input Voltage If you have a persistent Error 1027 that

: Use a multimeter to check that the incoming AC mains voltage is stable and within the drive's specified nameplate range. Manual Reset : Press the

button on the Local Control Panel (LCP) to attempt to clear the alarm. Hardware Check

: Ensure all option cards and internal wiring connections are secure. Øwre-Johnsen Advanced Recovery: Manual Initialization

If a standard reset does not clear the error, you may need to perform a Manual Initialization to return the drive to factory default settings. This will erase all user-programmed parameters. MyDrive® Assistant Power off the drive. Press and hold the [Main Menu] keys simultaneously.

Power on the drive while continuing to hold the keys for 5 seconds.

Release the keys; the drive should now be in its default state. MyDrive® Assistant Recommendation

If Error 1027 persists after power cycling and initialization, it indicates a critical internal hardware failure

(likely the power board or control card). You should contact a certified Danfoss Service Department for repair or replacement. Top ten VFD tech support calls - Danfoss

Understanding and Troubleshooting Danfoss Error 1027: A Comprehensive Guide

Danfoss is a well-known manufacturer of industrial and commercial refrigeration, air conditioning, and heating systems. Their products are widely used in various industries, including retail, food processing, and HVAC. However, like any complex system, Danfoss products can sometimes experience errors and malfunctions. One common error code that users may encounter is Danfoss Error 1027. In this article, we will explore what Danfoss Error 1027 means, its causes, and troubleshooting steps to help you resolve the issue.

What is Danfoss Error 1027?

Danfoss Error 1027 is a specific error code that appears on Danfoss control systems, indicating a problem with the system's operation. The error code is usually displayed on the control panel or screen of the Danfoss device. When Error 1027 occurs, it can disrupt the normal functioning of the system, leading to reduced performance, increased energy consumption, or even complete system shutdown.

Causes of Danfoss Error 1027

The causes of Danfoss Error 1027 can vary depending on the specific product and system configuration. However, based on common issues reported by users and Danfoss support teams, some possible causes of Error 1027 include:

Symptoms of Danfoss Error 1027

Before the error code appears, you may notice some symptoms that indicate a problem with the system. These symptoms can include:

Troubleshooting Danfoss Error 1027

To resolve Danfoss Error 1027, follow these troubleshooting steps:

Advanced Troubleshooting Steps

If the basic troubleshooting steps do not resolve the issue, you may need to perform more advanced troubleshooting steps, such as:

Preventing Danfoss Error 1027

To prevent Danfoss Error 1027 from occurring in the future, follow these best practices:

Conclusion

| 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. |