Danfoss Error 1027 ~upd~

Technical Write-Up: Danfoss Drive Error 1027

Technical Cause

The Danfoss drive monitors the "heartbeat" of the communication network. The master controller must send status updates or telegrams to the drive at regular intervals. The drive has an internal timer monitoring this activity. If the time between valid telegrams exceeds the setting in Parameter 8-04 "Control Word Timeout Time," the drive will trip on Error 1027.

Essentially, the drive is asking, "Are you still there?" and receiving no answer.

7. Prevention for Future

• Ensure brake resistor ohms ≥ minimum allowed (see drive manual, e.g., FC-102: 27Ω min for 380–480V units).
• Add a thermal switch (normally closed) in series with brake resistor and wire to a digital input programmed as Brake resistor thermistor (parameter 2-16).
• Set parameter 2-13 Brake Power Monitoring = [1] Warning or [2] Trip.
• Use shielded, short cables between drive and brake resistor (max 5 m / 16 ft unless using output filters).

Part 7: Frequently Asked Questions (FAQ)

Q1: Can a firmware update fix Error 1027?
Rarely. Danfoss has released patches for specific fieldbus stacks (especially early Profinet versions). Check the release notes for your drive’s current firmware version. danfoss error 1027

Q2: Does Error 1027 damage the drive?
No. It is a protective response. However, repeated stopping/starting of the load (pump, fan, conveyor) can cause mechanical wear.

Q3: Can I disable Error 1027 entirely?
Theoretically, set Parameter 8-03 Control Timeout Time = 100 seconds (max). But this is dangerous – the drive would run uncontrolled for over a minute. Not recommended for safety. Technical Write-Up: Danfoss Drive Error 1027 Technical Cause

Q4: Why does the error appear only on one drive in a network of 20?
Faulty option card, incorrect address, or damaged local cable segment. Isolate that drive’s cabling first.

Q5: Is Error 1027 the same as “Bus Off” on a CANopen drive?
Similar, but not identical. CANopen “Bus Off” means hardware-level fault. Error 1027 is higher-level protocol timeout. Ensure brake resistor ohms ≥ minimum allowed (see

Step 1 – Observe the Drive’s Local Display

• Is the alarm active (solid red LED, flashing alarm text)?
• Can you clear it with a manual reset ([Reset] key)?
• Does it return immediately or after a delay?

Immediate return → Hardware or configuration problem.
Delayed return (e.g., 1–5 seconds) → Timeout parameter or master issue.