Code 206200: <location>Infeed: Failure of one or several line phases
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical <location>Infeed: Failure of one or several line phases alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
Message value: Drive object: A_INF, S_INF Reaction: OFF2 (OFF1) Acknowledge: IMMEDIATELY (POWER ON) Cause: Failure overvoltage in one or several line supply phases. The fault can be output in two operating states: 1. During the power-on phase of the infeed unit. The measured line supply angle deviates from the regul ar characteristic for a 3-phase system - the PLL cannot be synchronized. The fault occurs immediately after power-up if, wh en operating with a VSM, the phase assignment L1, L2, L3 at the VSM differs from t he phase assignment at the power unit. 2. While the infeed is operational. After a voltage dip has been detected or an overvolt age (note A06205) in one or several line phases a fault occurred within 100 ms (also refer to other relevant messages). Generally, before fault message F06200 is output, Alarm A06205 occurs at leas t once, whose warning value can provide information regarding the cause of the line supply fault. Probable causes of the fault: - voltage dip on the line side or phase failure or overvoltage lasting longer than 10 ms. - overload condition on the load side with peak current. - commutating reactor missing. Remedy: - check the line supply and fuses. - check the connection and size (rating) of the line commutating reactor. - check and correct the phase assignment at the VSM (X521 or X522) and at the power unit. - check the load. - if failed in operation, carefully note the prev ious alarm messages A 6205 with alarm values. See also: p3463 (Infeed, line angle change, phase failure detection) SINAMICS-Alarms
Source: SINUMERIK 840D sl / 840Di sl / SINAMICS S120 Diagnostics Manual (DAsl, 03/2009)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Siemens SINUMERIK 840D CNC Alarms
Siemens controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 206200 on the SINUMERIK 840D CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Siemens's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4014 Siemens SINUMERIK 840D CNC codes.
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