Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Manual (Page 104)

4.2 Settings for Common Basic Functions
4-21
Operation
4.2.10 SEMI-F47 Function (Torque Limit Function for Low Power Supply Voltage for
Main Circuit)
The torque limit function detects a low voltage and limits the output current if the power supply voltage for the
main circuit drops to a specified value or below.
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.
• The 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.
• The 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 V SERVOPACKs.)
<Control Power Supply Restrictions>
400 V SERVOPACKs: Provide the control power supply from a 24 VDC power supply
that complies with SEMI F47 standards.
100 V SERVOPACKs: 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 controls 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 device to set parameters while confirming correct operation.
• Setting the Instantaneous Power Cut Hold Time (P.509) lengthens the amount of time
from when the power supply is turned OFF until the power actually stops flowing to
the motor. Send the servo OFF command to stop flowing the power to the motor.