During the operation of systems using Parker AC690+ drives, one of the most common faults that can cause unexpected machine shutdowns is the DESAT fault.
❓ What is a DESAT fault? How serious is it, and how can you fix it to prevent future occurrences?
In this article, we’ll break it down clearly and guide you through the most effective solutions.
🔎 What is a DESAT Fault?
DESAT (Desaturation) is a protection fault related to the IGBT inside the drive.
In systems using Parker AC690+, the DESAT fault occurs when:
- The IGBT is no longer operating in a saturated state
- The collector-emitter voltage (Vce) rises abnormally during conduction
👉 As a result, the drive will trip immediately to protect the power module from damage.
⚠️ Common Signs of a DESAT Fault
- The drive trips immediately upon RUN command
- The system stops suddenly during operation
- The fault can be reset, but it reoccurs repeatedly
- Typically happens under heavy load or during acceleration
🔥 Common Causes of DESAT Faults
1. Motor or Cable Short Circuit
- Motor insulation leakage
- Moisture in cables or damaged insulation
- Loose or poor connections
👉 This is the most common cause of DESAT faults.
2. IGBT Degradation (Aging Drive)
- The Parker AC690+ has been in operation for over 10 years
- Power components have deteriorated over time
➡️ More likely to trigger DESAT faults under increased load conditions.
3. Overload or Mechanical Jam
- Shaft blockage or mechanical jamming
- Excessive tension (especially in coating and packaging printing machines)
4. Unstable DC Bus Voltage
- Aging or degraded DC bus capacitors
- Voltage fluctuations or ripple
5. Electrical Noise (EMC Issues)
- Unshielded motor or signal cables
- Poor or improper grounding
6. Control Board Failure
- Faulty IGBT gate driver
- Incorrect or unstable measurement circuits
🛠️ DESAT Fault Troubleshooting & Repair Guide
✔️Step 1: Isolate the Motor from the Drive
- Disconnect the U–V–W motor cables
- Run the drive under no-load conditions
👉 If the fault still occurs → the issue is likely within the drive itself.
✔️Step 2: Check Motor Insulation
- Use a megohmmeter (insulation tester) to measure insulation resistance
- Acceptable value: > 10 MΩ
✔️Step 3: Check Mechanical Components
- Manually rotate the shaft to detect any jamming
- Inspect bearings and load conditions
✔️Step 4: Check Power Supply
- Measure the DC bus voltage
- Inspect the capacitors
✔️Step 5: Test with a Replacement Drive
- Swap with another drive if available
- Quickly identify whether the issue is drive-related
👉 If the fault disappears → the original drive is likely defective.
🚨 Important Warning
❌ Do not repeatedly reset and restart the drive when a DESAT fault occurs
➡️ This can lead to complete IGBT failure, resulting in very high repair costs.
❗ Why Consider Replacing the Parker AC690+?
The Parker AC690+ has now been discontinued.
Continuing to use this drive may lead to several risks:
- Difficulty in sourcing spare parts
- High maintenance and repair costs
- Reduced reliability over time
🔄 Replacement Solution: Parker AC20 & Parker AC30
🔹Parker AC20 – Cost-Effective Solution
- Easy to install and configure
- Optimized cost for budget-conscious projects
- Supports communication protocols such as PROFINET, with optional Profibus, CAN, etc.
🔹Parker AC30 – Advanced Upgrade Solution
- Higher performance compared to the Parker AC690+
- Supports modern communication protocols such as PROFINET, EtherNet/IP, Profibus, and more
- Powerful programming capabilities, enabling seamless replacement of legacy systems
💡 When Should You Upgrade?
👉 You should consider upgrading to Parker AC20 or Parker AC30 when:
- The Parker AC690+ frequently reports faults
- Your system requires higher stability and reliability
- Spare parts are difficult to source
- You want to upgrade communication and overall performance
✅ Conclusion
The DESAT fault is not just a simple error—it is a critical warning indicating underlying issues within the system.
👉 Optimal solutions:
- Properly diagnose and resolve the root cause if the Parker AC690+ is still in use
- Or upgrade to Parker AC20 / Parker AC30 to ensure long-term, stable operation
🔧 Contact for Consultation & Support
- On-site troubleshooting and inspection
- Repair services & supply of genuine Parker Hannifin drives
- Consultation for upgrading from Parker AC690+ to Parker AC20 / Parker AC30
- System configuration & recommissioning (Profibus, analog, multi-drive systems)
👉 Contact us now for fast and reliable support!
📞 Hotline: +84 908 353 714 (Mr. Lâm)
📧 Email : info@kythuatviet.vn
