Siemens alarm 300608: Axis %1 drive %2 speed controller at limit
SINUMERIK 840D/810D powerline drive alarm (SIMODRIVE 611D) · SIMODRIVE 611D/611U
What it means
The speed controller output sat at its torque/current limit longer than MD 1605 while speed stayed below threshold MD 1606. In practice the axis wants torque it cannot deliver - mechanically blocked, brake still applied, a phase missing, or feedback inverted so the controller pushes the wrong way.
Likely causes
- axis blocked, overloaded, or holding brake not released
- missing phase / wrong rotary field at motor connection
- encoder track inversion or wrong resolution (direction loop positive feedback)
- ground fault or winding fault in motor
- torque/current limits set too low (also after software exchange)
Triage note: Defaults: MD 1605 = 200 ms both; MD 1606 = 8000 rpm FDD / 30 rpm MSD. Vertical axes: verify counterbalance before blaming the drive.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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6SN1123-…
power-module · Common cause
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1FT6/1FK… motor incl. encoder
power-module · Common cause
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6SN1118-…
control-board · Check if others ruled out
Need the part urgently?
Send us alarm 300608 with your machine details — typical RFQ turnaround is 24–48h.