154
PARAMETERS
4.2.45 Zero current detection (Pr. 152, Pr. 153)
Pr. 152 "zero current detection level"
Pr. 153 "zero current detection period"
When the inverter's output current falls to "0", torque will not be generated. This may cause a drop due to
gravity when the inverter is used in vertical lift application.
To prevent this, the output current "zero" signal can be output from the inverter to close the mechanical brake
when the output current has fallen to "zero".
zIf the output current remains lower than the Pr. 152 setting during inverter operation for longer than the time
set in Pr. 153, the zero current detection (Y13) signal is output from the inverter's open collector output
terminal.
(Use any of Pr. 190 to Pr. 195 to assign the terminal used for Y13 signal output.)
<Setting>
Refer to the following list and set the parameters:
Parameter
Number
Factory
Setting
Setting Range
152 5.0% 0 to 200.0%
153 0.5 s 0 to 1 s
Parameter Number Description
152
Set the zero current detection level.
Set this parameter to define the percentage of the rated current at which the zero current will be detected.
153
Set the zero current detection period.
Set this parameter to define the period from when the output current drops below the Pr. 152 value until the
zero current detection signal (Y13) is output.
Note: 1. If the current rises, above the preset detection level and the condition is not satisfied, the zero
current detection signal is held on for about 100ms.
2. This function is also valid during execution of the online auto tuning.
3. Changing the terminal function using any of Pr. 190 to Pr. 195 may affect the other functions.
Confirm the functions of the corresponding terminals before making setting.
CAUTION
The zero current detection level setting should not be too high, and the zero current
detection time setting not too long. Otherwise, the detection signal may not be output
when torque is not generated at a low output current.
To prevent the machine and equipment from resulting in hazardous conditions by use
of the zero current detection signal, install a safety backup such as an emergency
brake.
Related parameters
Pr. 190 to Pr. 195
(output terminal function selection)
Output current 0 [A]
OFF ON
OFF ON
Pr.152
OFF ON
100 ms (Note)
Start signal
Pr. 152 "zero current
detection level"
Zero current detection
signal output (Y13)
Pr. 153 "zero current
detection period"
Pr. 153 "zero current
detection period"
