Rexroth servo fault code F8069:What does Rexroth servo fault code F8069 mean?
Q: What does Rexroth servo fault code F8069 mean?
A: Rexroth servo fault code F8069 indicates a problem with the motor temperature sensor, specifically a break in the sensor circuit or an invalid temperature signal. According to the official Rexroth IndraDrive troubleshooting manual, this diagnostic message appears when the drive controller detects an open circuit in the motor temperature monitoring connection. The drive will disable the power output to protect the motor from potential overheating damage. Common causes include a disconnected sensor cable, a faulty temperature sensor, or incorrect wiring at the motor feedback connector. Rexroth recommends checking the motor cable, the temperature sensor resistance, and the drive parameter settings for the temperature evaluation before resetting the fault.
Q: How can I fix Rexroth servo fault code F8069?
A: To clear Rexroth fault F8069, first power down the drive and inspect the motor temperature sensor wiring for breaks or loose connections. Using a multimeter, measure the sensor resistance at the feedback connector; for a KTY84 or PTC sensor, compare the reading with the values in the Rexroth IndraDrive manual. If the sensor is faulty, replace it. Also verify that the drive parameter for motor temperature monitoring (e.g., P-0-0512 or equivalent) matches the installed sensor type. After correcting the hardware, acknowledge the fault via the HMI or control system. If the fault persists, the drive controller input may be defective, requiring service.
Q: Which Rexroth drive systems can display fault code F8069?
A: Fault code F8069 is used across Rexroth IndraDrive series, including the IndraDrive C, IndraDrive M, and IndraDrive Cs families, as well as EcoDrive and some IndraDyn motor combinations. According to the official Rexroth IndraDrive Troubleshooting Guide (document DOK-INDRV*-GEN-**-IB**-EN-P), this diagnostic message appears in the drive firmware when the motor temperature monitoring circuit is interrupted. The exact display format may vary by firmware version, but the fault number F8069 is standardized for this sensor break condition. Always consult the specific manual for your drive model to confirm parameter numbers and wiring terminals.
Q: What are the possible causes of Rexroth servo error F8069?
A: Rexroth documentation lists several causes for F8069: an open circuit in the motor temperature sensor cable, a defective temperature sensor inside the motor, incorrect wiring between the motor and drive, or a mismatch between the configured sensor type and the actual sensor. Additionally, a loose connector at the motor feedback or drive end can trigger this fault. The official Rexroth IndraDrive manual notes that if the motor is equipped with a PTC or KTY sensor, the drive's temperature monitoring parameter must be set correctly. In some cases, electromagnetic interference on the sensor line may also produce an invalid signal, leading to F8069.
Q: Where can I find official documentation for Rexroth fault code F8069?
A: Official information for Rexroth fault code F8069 is available in the Rexroth IndraDrive Troubleshooting Guide, part of the IndraDrive documentation set. You can download it from the Bosch Rexroth website (www.boschrexroth.com) under the product support section for IndraDrive. Look for document number DOK-INDRV*-GEN-**-IB**-EN-P or the specific manual for your drive model. The guide includes a complete list of diagnostic messages, causes, and remedies. Additionally, Rexroth's online media directory and the IndraDrive parameter description manuals provide detailed explanations of temperature monitoring settings. Always use the latest version for accurate fault resolution.
Dialogue about
Common scenarios of "Rexroth servo fault code F8069"
【Operator】 Hi, our Rexroth servo drive is showing fault code F8069. What does that mean?
【Technician】 F8069 indicates a 'Power supply fault: undervoltage in DC bus'. The drive has detected that the DC bus voltage is below the minimum threshold.
【Operator】 Is it safe to keep running the machine?
【Technician】 No, you should stop the machine immediately. Continuing to run with undervoltage can cause erratic operation or damage the drive. Reset the fault and check the power supply.
【Operator】 How do I reset the fault?
【Technician】 You can reset via the HMI or by cycling power. But first, verify the incoming power and DC bus voltage.
【Operator】 What should the DC bus voltage be?
【Technician】 For a 400V system, the DC bus should be around 540V DC. If it's significantly lower, that's the issue.
【Operator】 I measured 480V DC. That seems low.
【Technician】 Yes, 480V is too low. Check the incoming AC supply. Is it within spec?
【Operator】 The AC line is 380V, which is within our normal range.
【Technician】 Then the issue might be in the drive's rectifier or the DC bus capacitors. Also check for loose connections.
【Operator】 I'll check the connections. What else could cause F8069?
【Technician】 Other causes: a blown fuse in the drive, faulty braking resistor, or a problem with the power supply module. Also, if the drive is under heavy load during acceleration, it might dip.
【Operator】 I found a loose terminal on the DC bus. Could that be it?
【Technician】 Absolutely. A loose connection can cause voltage drop under load. Tighten it and reset the fault. Monitor the voltage.
【Operator】 I tightened it and reset. The fault cleared. But I'm still getting occasional F8069.
【Technician】 Intermittent F8069 could indicate aging capacitors or a failing power supply. Check the capacitor bank for bulging or leakage.
【Operator】 The capacitors look fine. Could it be the braking resistor?
【Technician】 Yes, if the braking resistor is open or disconnected, the drive can't dissipate regenerative energy, causing overvoltage, but undervoltage is less common. However, a faulty braking chopper could affect the bus. Test the resistor with a multimeter.
【Operator】 I'll test it. Thanks for the help!