SINAMICS G120 trips F30005 after running a while, what to check?
My SINAMICS G120 drive (CU240E-2) keeps tripping with F30005 after the machine runs for about 20 minutes. I've noticed the A07805 alarm comes on before the trip. What should I check first?
Fault F30005 on a SINAMICS G120 indicates that the Power Module has been overloaded, meaning its I2t value (r0036) reached 100%. This typically happens when the permissible rated current is exceeded for too long or the load duty cycle is not maintained. The A07805 alarm serves as a warning before the trip occurs.
Likely causes and checks
1Continuous load above the Power Module rating
- Points to it
- The Power Module is continuously operating above its rated capacity, causing its I2t value to steadily climb until it reaches 100% and trips the drive.
- Check
- Trend the r0036 (Power unit overload I2t) and the output current. If r0036 climbs steadily and A07805 appears before the trip, consider reducing the continuous load or installing a Power Module with a higher rating.
2Duty cycle not respected
- Points to it
- The drive is undergoing repeated heavy starts or frequent start/stop cycles that exceed the Power Module's permissible load duty cycle, leading to thermal overload.
- Check
- Compare the actual start/stop cycle of the machine with the permissible load duty cycle specified for the Power Module. If the trip occurs after several quick starts, this is a likely cause.
3Motor and Power Module current ratings mismatched
- Points to it
- The motor's rated current is too close to or exceeds the Power Module's rated current, making the Power Module prone to overload under normal operating conditions.
- Check
- Verify and compare the rated currents of both the motor and the Power Module. Ensure the Power Module is adequately sized for the connected motor.
4Current limit set too high
- Points to it
- The current limit parameter (p0640) is set significantly above the motor's rated current, allowing the Power Module to draw excessive current for extended periods.
- Check
- Check parameter p0640. If it is well above the motor's rated current, reduce its value. For U/f operation, also consider reducing p1341 (current limiting controller integral time).
Next check: Given that the A07805 alarm appears before the trip and the fault occurs after running for a while, the most likely cause is a continuous load exceeding the Power Module's rating. Start by trending r0036 and the output current to confirm this.
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