TECO A510s - Zero-Servo Gain Setting; Zero-Servo Count; Operation Selection of Zero-Speed Braking

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- Use one of multi-function digital inputs (03-00 to 03-07) set to 46 to execute the zero-servo command.
- If the frequency reference is lower than the zero speed level (the larger of 01-08 or 07-06 (DC braking start
frequency)), zero servo operation is active (zero servo start position) and the motor shaft will remain in the
same position even if the analog reference signal level is greater than 0.
- Deactivating multi-function input set for zero-servo, deactivates the zero-servo operation.
- Use multi-function digital outputs (03-11, 03-12 = 31) for zero-servo completed indication.
- Zero-servo count 11-50 is used when one of multi-function digital outputs is set to 31 (zero-servo completed).
- Zero-servo completion is enabled when the motor shaft position count falls within the zero-servo starting
position ± servo counts set in parameter 11-50.
- Zero-servo or normal operation command is active when zero-servo completion signal is turned off.
11-49: Zero-servo gain setting
Use the zero-servo gain parameter 11-49 to adjust the holding torque in zero-servo operation. If the set value is
increased, the holding torque will increase but instability may occur. Do not use the zero-servo function at 100%
of the inverter rated current as this may cause the inverter to overheat (OH1). Zero-servo may permanently be
used to maintain 50 – 60% of the inverter rated current. Increase inverter rating if more is required.
11-50: Zero-servo count
Zero servo count is used to specify the zero-servo position offset from the zero-servo start position used for
zero-servo completion.
11-51: Operation selection of zero-speed braking
In V/F control mode, the DC braking operation (without PG feedback) can be used to the motor shaft.
Set 11-51 to select zero-speed braking operation to 1 to enable this function.
To use DC braking operation set parameter 00-02 (operation command selection) to 1 and parameter 00-05
(frequency reference selection) to 1, the operation command and frequency reference are now set for external
control. When the frequency reference is 0V (or less than 4mA), and the operation command is turned on, the
zero-speed ‘DC’ braking operation is activated and holding torque is generated using DC braking.
Refer to Figure 4.3.97 for more information on zero-speed DC braking operation.
Note: DC braking 07-07 is limited to 20% of the inverter rated current.