Siemens 840D system alarm 300608 # troubleshooting

In the 2016 Lunar Mid-Autumn Festival, there was no sign of a pause in a city in the south due to continuous rain.
The annual reunion scene of "Flowing the Moon Full Moon" was ruined by the "annoying" phone. There was no mood because the company had a Siemens 840D system equipment failure. After learning from the phone that there were 2 Z-axis failures Unable to move, 1 Z axis automatically descends when the device stops, causing an overtravel alarm. It seems that the usual telephone communication cannot repair this fault, and can only give up the vacation and rush to the company.
When you arrive at the company site, start the device and open the "Diagnosis" message interface. A long list of fault information first comes into view, including: 25201 # Aixs Z1 drive fault300608 # Aixs Z1 Drive 6 speed controller at limit21612 # Channel 1 axis Z1 / Z1: enable reset, cause 3510102 # U / E module 1 is interrupted (I32.6 = 1).
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A careful analysis of the content of the fault information basically locates at 300608 # fault.
The basic reasons for this fault are: (in-use equipment) 1. The motor is stuck, the load is too heavy, or the brake is turned off. 2. If the power module allows it, the rotation torque limit and power can be increased slightly. Limit and current limit, 3. Check whether the motor is grounded, 4. Check the motor inverter connection (missing phase, wrong rotation area), 5. Check whether the encoder, encoder cable and protective screen board are in bad contact or the cable is disconnected, 6. Check the encoder cable, you can experiment with other coordinate encoder cable replacement, 7. Check the DC bus connection (check whether the screws are tight), 8. Check the servo shaft driver (power supply, power module), I am balancing from the hydraulic pressure The cylinder control unit starts to detect that the pressure of the hydraulic system is normal; the hydraulic part is shown as follows:
1) Detect the hydraulic number (70.0) relief valve. After the diesel is cleaned, adjusting the relief pressure can be adjusted normally.
2) No abnormality was found in 3 balance cylinders.
3) It is normal to check the hydraulic number (61.1) pressure regulating valve, which can freely adjust the pressure range.
4) It is normal to check the hydraulic number (61.01) hydraulic control check valve, which can lock the shaft after cleaning.
5) It is normal to judge that the hydraulic system is normal if no oil leakage or leakage in the cylinder is found when checking the hydraulic pipeline connections of the three shafts.
Resolutely start from the Z1 shaft drive belt in channel 1, and manually move a mechanical shaft.
There is no jam on the side of the screw rod and the screw nut, and there is a jam phenomenon on the servo motor and the gearbox side.
Reconfirm that the 24V power supply of the brake coil is normal, the control unit is normal, and the line connection is normal.
View the axis drive parameter interface and refer to the "smooth current value" data.
When in the "JOG" state, if you click the "+" or "-" button, the current quickly rises to more than 100%, and an appeal failure message is reported.
Retest the motor of the shaft: the three-phase resistance is basically the same without grounding, the DC resistance of the brake is 2K ohms, and the detection of 25.2V at the 24V terminal (line plug) is normal.
Disconnect the servo motor (motor model: 1FT6108-8SF71-1EH0, the built-in encoder is HEIDENHAIN EOM1325048-2048) and connect to the transmitter. The manual disk motor is connected to the transmitter side, and no jamming is found on the transmission side , The stuck position is on the servo motor side (it is unknown whether it is a motor bearing or a brake assembly).
Z-axis control unit diagram:
  Remove the motor to the workbench, open the rear end cover, and loosen the encoder fastening screws (without any markings), then open the front and rear end covers successively. The bearing 6208 is flexible and normal, because the brake is ineffective. Causes the current to surge after the servo motor starts.
In order not to delay production tasks, after communicating with the production equipment department, remove the holding brake assembly, reinstall the motor, manually turn the servo motor, and test the machine flexibly.
System report 300509 #; 35201 #; 27010 #; 27023 #; 27024 # alarm information, check the diagnosis manual, the fault phenomenon is the monitoring of the safety range of the static error and exceeding the safety tolerance.
I have seen some forums and exchanges before, and I am very particular about the installation position of the encoder.
Re-open the rear cover of the servo motor, remove the encoder, and carefully check the shaft mark and the mark on the encoder. It does.
Manually turning the motor to overlap the three marks and then tighten the encoder screws, the failure message of the startup appeal disappeared, it seems that the hope of distance repair is in sight.
The tool to remove the encoder is shown in the figure:
  After installing the units of channel 1 again, the system was started and no alarm message was found.
Move the position of the 1Z1 axis of the channel to a certain value, check it with a measuring tool, and set the configuration value MD34100 or MD34090.
After several movements and verification of the measuring tool, the position basically meets the requirements, and the upper and lower limit positions are correct.
Channel 2 and Channel 3 were processed in the same way. The positional relationship between the encoder and the servo motor, which is very important this time, makes handling and debugging much easier.
The movement position of each axis and the actual measuring tool error are controlled within 0.005mm.
After loading the processing program, test the machine in the "AOUT" state, and start the small feed. The long-lost multi-channel axes slowly moved according to the specified trajectory. After testing several times, the notification was already waiting. The production department arranges normal production.
So, pack up tools, materials, and computers for "eating" tools, and then look at the mobile phone time at 8:15 pm on September 18, a full 3 days and 3 nights, this is the life of the labor controller festival.
This troubleshooting summary: 1) The Siemens servo encoder must be completely marked before disassembly! Disassembly uses homemade special tools.
2) Focus on the system's alarm information and carry out investigations. Think decisively and resolutely.
3) Take notes and notes regularly.
4) When you encounter new problems, keep your head calm and analyze the correlation between alarm messages.
5) The after-fault records must be detailed for future reference.

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