4 APPLICABLE FUNCTIONS
4.18 Disconnection/incorrect wiring detection function
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Output open phase detection function
This function detects an open phase due to servo motor power supply cable (U/V/W) disconnection and generates [AL. 139
Open-phase error] after the detection.
Restrictions [G] [WG]
• The output open phase detection function will be disabled if an alarm or warning other than [AL. 139 Open-phase error] has
occurred.
• If "1" is set in [Pr. PC05.0 Motor-less operation selection], output open phase will not be detected even if the output open
phase detection function has been enabled.
• If "0" (servo motor speed) is set in [Pr. PC19.6 Output open phase - Judgment speed selection], [AL. 139 Open-phase
error] will only be detected in the servo-on state while the servo motor speed is 50 [r/min] (linear servo motor: 50 [mm/s],
direct drive motor: 25 [r/min]) or faster. The output open phase will not be detected even if the open phase of the servo
motor power supply (U/V/W) occurs while in the servo-off state or if the servo motor speed is under 50 [r/min] (linear servo
motor: 50 [mm/s], direct drive motor: 25 [r/min]).
• If "1" (speed command) is set in [Pr. PC19.6 Output open phase - Judgment speed selection], [AL. 139 Open-phase error]
will only be detected in the servo-on state while the command speed is 50 [r/min] (linear servo motor: 50 [mm/s], direct drive
motor: 25 [r/min]) or faster. The output open phase will not be detected even if the open phase of the servo motor power
supply (U/V/W) occurs while in the servo-off state or if the command speed is under 50 [r/min] (linear servo motor: 50 [mm/
s], direct drive motor: 25 [r/min]).
• The output open phase detection is not performed when the MBR is on.
• If "1" (speed command) is set in [Pr. PC19.6 Output open phase - Judgment speed selection], the output open phase may
be detected incorrectly when the servo motor axis is stopped due to a collision or similar impact.
• If [Pr. PA11 Forward rotation torque limit] and [Pr. PA12 Reverse rotation torque limit] are 10.0 % or less, the output open
phase may be detected incorrectly when the servo motor load becomes too large.
• If a linear servo motor is used, the open phase may not be detected.
Restrictions [A]
• The output open phase detection function will be disabled if an alarm or warning other than [AL. 139 Open-phase error] has
occurred.
• If "1" is set in [Pr. PC60.0 Motor-less operation selection], output open phase will not be detected even if the output open
phase detection function has been enabled.
• If "0" (servo motor speed) is set in [Pr. PC26.6 Output open phase - Judgment speed selection], [AL. 139 Open-phase
error] will only be detected in the servo-on state while the servo motor speed is 50 [r/min] (linear servo motor: 50 [mm/s],
direct drive motor: 25 [r/min]) or faster. The output open phase will not be detected even if the open phase of the servo
motor power supply (U/V/W) occurs while in the servo-off state or if the servo motor speed is under 50 [r/min] (linear servo
motor: 50 [mm/s], direct drive motor: 25 [r/min]).
• If "1" (speed command) is set in [Pr. PC26.6 Output open phase - Judgment speed selection], [AL. 139 Open-phase error]
will only be detected in the servo-on state while the command speed is 50 [r/min] (linear servo motor: 50 [mm/s], direct drive
motor: 25 [r/min]) or faster. The output open phase will not be detected even if the open phase of the servo motor power
supply (U/V/W) occurs while in the servo-off state or if the command speed is under 50 [r/min] (linear servo motor: 50 [mm/
s], direct drive motor: 25 [r/min]).
• The output open phase detection is not performed when the MBR is on.
• If "1" (speed command) is set in [Pr. PC26.6 Output open phase - Judgment speed selection], the output open phase may
be detected incorrectly when the servo motor axis is stopped due to a collision or similar impact.
• If [Pr. PA11 Forward rotation torque limit] and [Pr. PA12 Reverse rotation torque limit] are 10.0 % or less, the output open
phase may be detected incorrectly when the servo motor load becomes too large.
• If a linear servo motor is used, the open phase may not be detected.
Precautions
• With the output open-phase detection function, detection is possible only when one of the U, V, or W phases is an open
phase.