A07918 — Three-phase setpoint generator operation selected/active

A07918 is an alarm (and can, depending on the drive configuration, also be output without any reaction, N) that reports the following operating state: the drive is set for a separately excited synchronous motor (p0300 = 5) and the active open-loop/closed-loop control mode is I/f control (open-loop) with a fixed current (p1300 = 18). In this mode the speed comes from the setpoint channel, while the current setpoint is fixed at the stator minimum current p1620. The message draws attention to the fact that the control dynamic performance in this mode is very limited, so longer ramp-up times for the speed setpoint are expected than in normal operation.

• Only for separately excited synchronous motors (p0300 = 5): the selected open-loop/closed-loop control mode is I/f control (open-loop) with a fixed current (p1300 = 18); the speed is entered via the setpoint channel and the current setpoint is given by the stator minimum current p1620.
• The drive raises the message because in this mode the control dynamic performance is very limited — longer ramp-up times should be set for the setpoint speed than for normal operation.

1. Check p0300: the message is only issued when the motor is configured as a separately excited synchronous motor (p0300 = 5).
2. If the limited control dynamic performance of this mode does not suit the application, select another open-loop/closed-loop control mode in p1300 — this is the remedy the manual gives.
3. If the drive stays in I/f control with fixed current (p1300 = 18), set longer ramp-up times for the setpoint speed than for normal operation.

• p0300 (Motor type selection) — must read 5 (separately excited synchronous motor) for this alarm to appear; check it first.
• p1300 (Open-loop/closed-loop control operating mode) — value 18 (I/f control, open-loop, fixed current) is what triggers A07918; selecting another mode here is the remedy.
• p1620 (Stator current minimum) — in this mode it supplies the fixed current setpoint the drive runs with.

No acknowledgment is needed and the drive does not trip: the condition is signalled while the mode is selected, and the alarm is gone once another open-loop/closed-loop control mode has been chosen in p1300. As long as p1300 = 18 remains set, the message stays present.