F07311 — Bypass motor switch

F07311 "Bypass motor switch" belongs to the bypass function. The drive monitors the feedback signals of the bypass motor switch and raises this fault when one of these checks fails: a feedback signal is missing, the positive feedback signal arrives later than the specified time after a switching operation, or the drive switch position is not consistent with the bypass state. The drive writes the specific cause bitwise binary into the fault value r0949, so reading the fault value shows exactly which check failed.

• The switch "Closed" feedback signal is missing.
• The switch "Open" feedback signal is missing.
• The switch feedback signal is too slow: after switching, the drive waits for the positive feedback signal and issues a fault trip (shutdown) if the signal is received later than the specified time.
• The drive switch feedback signal is not consistent with the bypass state — the drive switch is closed when switching-on or when switching-in the motor.

1. Read the fault value r0949 bitwise binary to see which bit is set (Bit 1, 2, 3 or 6 — see the decoding below).
2. Check the transfer of the feedback signals. The signal the drive evaluates as the bypass switch feedback is assigned in p1269 (BI: Bypass switch feedback signal).
3. Check the switch itself.
4. If Bit 3 is set, check whether the positive feedback signal reaches the drive within the monitoring time set in p1274; if it is received later than this specified time, the drive trips.
5. If Bit 6 is set, compare the feedback of the drive switch with the bypass configuration and the changeover/command settings (p1260, p1266, p1267).

The message value is the fault cause from r0949, displayed in binary (%1 bin). Interpret it bitwise:

• Bit 1 — switch "Closed" feedback signal missing.
• Bit 2 — switch "Open" feedback signal missing.
• Bit 3 — switch feedback signal too slow. After switching, the drive waits for the positive feedback signal; if the feedback signal is received later than the specified time, a fault trip (shutdown) is issued.
• Bit 6 — drive switch feedback signal not consistent with the bypass state: the drive switch is closed when switching-on or when switching-in the motor.

• r0949 — fault value: read it bitwise binary to determine which feedback condition triggered F07311.
• p1260 — bypass configuration: the configuration of the bypass function whose switch feedback is monitored; check it when the feedback contradicts the bypass state (Bit 6).
• p1266 — BI: bypass control command: the source of the command that performs the bypass changeover.
• p1267 — bypass changeover source configuration: check it when the switch feedback does not match the bypass state (Bit 6).
• p1269 — BI: bypass switch feedback signal: the input where the drive expects the switch feedback; check the transfer of this signal here.
• p1274 — bypass switch monitoring time: the specified time within which the positive feedback signal must be received after switching; feedback that arrives later trips the fault.

The drive coasts down on this fault and must be acknowledged before it will start again. Remove the cause first — check the transfer of the feedback signals and check the switch, and make sure the positive feedback arrives within the monitoring time in p1274 — then acknowledge the fault immediately.