Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Analog Voltage and Pulse Train Reference - Manual (Page 131)

5.2 Basic Functions Settings
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5.2.7 SEMI F47 Function (Torque Limit Function for Low DC Power Supply Voltage
for Main Circuit)
The torque limit function detects an undervoltage warning and limits the output current if the DC power sup-
ply voltage for the main circuit in the SERVOPACK drops to a specified value because the power was
momentarily interrupted or the power supply voltage for the main circuit was temporality lowered.
This function complies with SEMI F47 standards for semiconductor production equipment.
Combining this function with the parameter for Instantaneous Power Cut Hold Time allows the servomotor to
continue operating without stopping for an alarm or without recovery work even if the power supply voltage
drops.
• This function is able to cope with instantaneous power interruptions in the voltage and
time ranges stipulated in SEMI F47. An uninterruptible power supply (UPS) is
required as a backup for instantaneous power interruptions that exceed these voltage
and time ranges.
• This function is intended for voltage drops in the main circuit power supply. The follow-
ing restrictions apply when it is used to provide an instantaneous power cut hold time
in the control power supply. (There are no restrictions for the 200-VAC SERVO-
PACKs.)
<Control Power Supply Restrictions>
SERVOPACK with 400-VAC Power Input: Provide the control power supply from a 24-
VDC power supply that complies with SEMI F47 standards.
SERVOPACK with 100-VAC Power Input: Provide the control power supply from an
uninterruptible power supply (UPS).
• Set the host controller and SERVOPACK torque limit so that a torque reference that
exceeds the specified acceleration will not be output when the power supply for the
main circuit is restored.
• Do not limit the torque to values lower than the holding torque for the vertical axis.
• This function limits torque within the range of the SERVOPACK's capability when the
power is cut. It is not intended for use under all load and operating conditions. Use the
actual machine to set parameters while confirming correct operation.
• Setting the Instantaneous Power Cut Hold Time lengthens the amount of time from
when the power supply is turned OFF until the motor current turns OFF. Turn the
servo ON signal ON and OFF to instantly stop the motor current.