Danfoss Error 1027

Set Parameter 8-04 = [1] Freeze output or use a custom ramp. This prevents mechanical shock if communication fails momentarily.

| Finding | Action | |---------|--------| | Shorted brake resistor | Replace resistor and brake IGBT (drive repair or replacement) | | Shorted IGBT only | Replace drive power section or entire drive (component-level repair for advanced techs) | | External wiring short | Repair wiring, then verify IGBT still healthy (often already damaged) | | Gate driver fault | Return drive to Danfoss service center |

🛑 Do not simply replace the brake resistor and run again – the IGBT is almost certainly dead and will trip immediately.

In Danfoss documentation (specifically for VLT® drives with fieldbus options), Alarm 1027 is defined as: "Bus communication fault – Timeout."

It appears under different sub-codes depending on the drive series:

Default 0.1 sec is too aggressive for noisy networks. Increase Parameter 8-03 to 0.5–1.0 sec to tolerate minor telegram loss.

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. danfoss error 1027

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?

In the world of industrial maintenance, the Danfoss Error 1027 is more than just a code— it is often a signal of a critical Internal Error

that requires the drive to be replaced or repaired by a specialist

Here is a short story looking at this error through the eyes of a technician. The Ghost in the Machine: A "1027" Story

The hum of the HVAC plant was usually a comfort to Elias, a steady vibration that meant everything was running as it should. But at 3:00 AM on a Tuesday, that hum died, replaced by the sharp silence of a tripped chiller.

Elias wiped the grease from his hands and stepped toward the glowing keypad of the Danfoss FC 102

drive. He expected the usual suspects—maybe a Phase Loss (Alarm 4) or perhaps an Earth Fault (Alarm 14) from a damp motor cable. Instead, the screen stared back with four cold digits:

"Internal Error," Elias muttered, his heart sinking. He knew the standard troubleshooting by heart: check the DC bus voltage, look for loose MC4 connectors, or verify the 24V control supply. But

wasn't a warning about external wiring or a dirty heat sink. It was a failure of the "brain" itself—a communication breakdown between the control card and the power card that the drive couldn't fix on its own. Set Parameter 8-04 = [1] Freeze output or

He tried the "Old School" reset: he disconnected the motor, cycled the line power, and waited for the capacitors to bleed dry. When the power clicked back on, the cooling fans whirred for a second, and for a moment, Elias hoped. Then, with a digital click, the "1027" returned like a stubborn ghost.

In the world of Danfoss, this was the "Contact Your Supplier" code. It meant the internal diagnostic checks had found a terminal fault in the power supply board or the control logic.

As the sun began to rise over the quiet plant, Elias reached for his phone to call the local distributor. The machine wasn't just tired; it was broken from the inside out. Troubleshooting Tips for Error 1027

While often terminal, you can attempt these steps before calling for a replacement: Power Cycle

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

: Disconnect the motor cables and attempt to power up the drive alone to see if the internal error clears. Check Control Wiring

: Ensure there is no excessive load on the 24V supply (terminal 12 or 13) that might be crashing the control card. Contact Support

: If the code persists after a full power cycle with no motor connected, the internal hardware is likely faulty. in your area to help with a repair?

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 🛑 Do not simply replace the brake resistor

: 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

For qualified technicians only – high energy stored in capacitors.

Using a multimeter in diode mode (or resistance low-ohms):

| Measurement (drive disconnected from mains, brake resistor disconnected) | Healthy Reading | Shorted IGBT Reading | |--------------------------------------------------------------------------|----------------|----------------------| | Between BR+ and BR- (some drives) or DC+ and BR terminal | Diode drop 0.3–0.8V one way, OL reverse | 0.0V or very low both ways | | Between BR- and DC- (common config) | Same as above | Short both ways |

If shorted both directions → IGBT failed.

Error 1027 — Compressor start attempts exceeded

(If you want a shorter label or a one-line message for a display, use: "Error 1027 — Compressor start attempts exceeded; check compressor, motor, and power.")

Disclaimer: This guide is for general troubleshooting. Always refer to your specific Danfoss product manual and consult a qualified electrician or technician before servicing the drive.