What causes Siemens SINUMERIK alarm 300501?

1.. A serious fault occured during actual current measurement.. 2..

How do I fix Siemens SINUMERIK alarm 300501?

1. Please inform the authorized personnel/service department. 2. Modify MD 1107: $MD_INVERTER_MAX_CURRENT (transistor limit current) - Check the motor data (motor code) - Check the controller data, current/speed controller gain too high - Reduce MD 1145: $MD_STALL_TORQUE_REDUCTION (stall torque reduction factor). 3. Check the power section and motor terminals (including motor protection), possibly power section too small - Increase MD 1254: $MD_CURRENT_MONITOR_FILTER_TIME (time constant for current monitoring) - Error in actual current measurement (if necessary, replace 611D power section or controller module) - If rotor position identification is active, check MD 1019 $MD_CURRENT_ROTORPOS_IDENT (current for rotor position identification) and, if necessary, reduce the setting. 4. Switch control OFF - ON

axismd.ai

Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 15 - 45 minutes

Alarm 300501

Siemens 300501 - Axis drive maximum current monitoring

SINUMERIK alarm 300501 indicates a critical safety-related fault in the PLC system that compromises the safety chain integrity. This alarm typically fires when safety I/O modules fail, safety program execution errors occur, or when there's a communication breakdown between the NCU and safety PLC components.

Siemens SINUMERIKServo/AxisIntermediate15 - 45 minutes

300501

Siemens 300501 - Axis drive maximum current monitoring

Axis drive maximum current monitoring

Root Cause Summary

SINUMERIK alarm 300501 indicates a critical safety-related fault in the PLC system that compromises the safety chain integrity. This alarm typically fires when safety I/O modules fail, safety program execution errors occur, or when there's a communication breakdown between the NCU and safety PLC components.

Safety

Drive/power/encoder circuit: hazardous voltages may remain in the DC link after power-off. Lock out / tag out, wait for discharge per the drive documentation, and use qualified personnel only.

Causes and Fixes

1
Check Safety I/O Status
Navigate to HMI > Diagnostics > Hardware > Safety I/O and examine all F-DI/F-DO module status indicators for red fault states.
Look specifically for modules showing 'SF' (System Fault) or 'BF' (Bus Fault) LEDs on the physical hardware.
2
Verify Safety Bus Communication
In STEP 7 Safety, check the F-system diagnostic buffer for communication errors between F-CPU and distributed safety I/O via PROFISAFE protocol.
Do not attempt to force safety I/O states - this will extend the fault condition.
3
Replace Faulty Safety Module
If hardware fault is confirmed, power down system and replace the identified F-DI or F-DO module, then restore safety configuration from backup.
Always verify the F-Destination Address matches the original module configuration in HW Config.

Service Recommendedhigh confidence

Call a technician if:

·Safety system modifications required
·F-CPU hardware replacement needed
·Safety validation testing required
·Multiple safety components showing faults

Prevention

Regular safety system diagnostic checks
Maintain backup of safety configuration
Monitor F-CPU diagnostic buffer weekly
Ensure proper environmental conditions for safety hardware

Common Mistakes

Attempting to bypass safety functions
Modifying safety parameters without validation
Ignoring safety hardware diagnostic indicators
Forcing safety I/O states during troubleshooting

Related Alarms

300502 300510 300520 61000 61001

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.