MITSUBISHI ELECTRIC FR-S520 - Manual (Page 90)

81
2
2
.5.2 Zero current detection
When the inverter's
output current falls to
"0", torque will not be
generated. This may
cause a gravity drop
when the inverter is
used in vertical lift
application. ON
Start signal
OFF
Pr.50
Pr.51
detection time
OFF OFF
100ms
ON ON
Pr.51
detection time
Pr.50
"zero
current
detection
level"
Output
current 0 [A]
Zero current
detection signal
output (Y13)
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".
Parameter Name
Factory
Setting
Setting
Range
Remarks
50
Zero current detection
level
5% 0 to 200%
51
Zero current detection
time
0.5s 0.05 to 1s
Setting is enabled when Pr. 30
= "1"
POINT
If the output is lower than the Pr.50 setting for longer than the time set in Pr. 51
during inverter operation, the zero current detection (Y13) signal is output from the
inverter's open collector output terminal.
<Setting>
Parameter Description
50
Set the zero current detection level.
Set the level of zero current detection in terms of the percentage of the rated
inverter current from the output current value of 0 [A].
51
Set the zero current detection time.
Set a period of time from when the output current falls to or below the Pr. 50
setting to when the zero current detection signal (Y13) is output.
CAUTION
•
If the current falls below the preset detection level but the timing condition is not
satisfied, the zero current detection signal is held on for about 100ms.
•
When the terminal functions are changed using Pr. 64, Pr. 65, the other functions
may be affected. Confirm the functions of the corresponding terminals before
making settings.
•
When one inverter is used to run (connect) multiple motors sequentially, the zero
current detection signal (Y13) may be output. Set 13% or more for the 0.1K, and
8% or more for the 0.2K. (If the sum of motor capacities is less than the zero
current detection level current or if the motor capacity per motor is less than the
zero current detection level current)
♦ ♦ ♦ ♦
Related parameters
♦ ♦ ♦ ♦
Assignment of Y13 signal to terminal
⇒
Pr. 64 "RUN terminal function selection", Pr. 65 "A, B, C
terminal function selection" (refer to page90)