Zero Current Detection (Pr. 50 , Pr. 51 ) - Mitsubishi Electric FR-S520E Series Instruction Manual

Current detection function
2.5.2 Zero current detection (Pr. 50
When the inverter's
output current falls
to "0[A]", torque will
not be generated.
This may cause a
gravity drop 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 "0[A]".
Parameter
50 Zero current detection level
51 Zero current detection period
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 or contact output terminal.
<Setting>
Parameter
Set the zero current detection level.
50 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].
Set the zero current detection period.
51 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.
Use Pr. 64 or Pr. 65 (output terminal function selection) to assign the terminal used for
Y13 signal 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.
•Changing the terminal functions using Pr. 64 and Pr. 65 may affect the other
functions. Please make setting after confirming the function of each terminal.
•When running (connecting) multiple motors with one inverter in due order, 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.
(when the total capacity of motors is less than the zero current detection level
and the motor capacity per inverter is less than the zero current detection level)
♦
Related parameters
•
Assignment of Y13 signal to terminal ⇒ Pr. 64 "RUN terminal function selection", Pr. 65 "A, B, C
Start signal
Output
current 0 [A]
Zero current
detection signal
output (Y13)
Name
♦
terminal function selection" (refer to page 110)
, Pr. 51
OFF ON
Pr.50
OFF ON
Pr.51
detection period
Factory Setting
Setting Range
5% 0 to 200% Setting is enabled when
0.5s 0.05 to 1s
Description
98
)
Pr.50
"zero
current
detection
100ms
level"
OFF ON
Pr.51
detection period
Remarks
Pr. 30 = "1"