Toshiba Tosvert VF-AS1 - Manual (Page 166)

E6581301
F-54
6
6.33 Protection functions
6.33.1 Setting of stall prevention level
H : Stall prevention level
Warning
Prohibited
• Do not set the stall prevention level (H) extremely low.
If the stall prevention level parameter (H) is set at or below the no-load current of the motor, the stall
preventive function will be always active and increase the frequency when it judges that regenerative
braking is taking place.
Do not set the stall prevention level parameter (H) below 30% under normal use conditions.
• Function
This parameter reduces the output frequency by activating a current stall prevention function against a
current exceeding the H-specified level.
[Parameter setting]
Title Function Adjustment range Default setting
H Stall prevention level  ~%, :Deactivated 
[Display during the alarm QE]
During an QE alarm status, (that is, when there is a current flow in excess of the stall prevention level), the output
frequency changes. At the same time, to the left of this value, “E” is displayed flashing on and off.
Example of display
6.33.2 Inverter trip record retention
H : Inverter trip record retention selection
• Function
If the inverter trips, this parameter will retain the corresponding trip information. Trip information that has
thus been stored into memory can be displayed, even after power has been reset.
[Parameter setting]
Title Function Adjustment range Default setting
H Inverter trip record retention selection
 :Clear when power is turned off.
 :Retain even after power is turned off.

+ Up to four sets of latest trip records displayed in status monitor mode can be stored into memory.
+ Data (current, voltage, etc.) displayed in status monitor mode when the inverter is tripped is cleared when power is
turned off.
■ Flow of operation when H=
Power supply reset
Operation panel
(terminal) reset
Inverter trip
Retention of failure
records is also canceled. Ready for normal
operation
Turn on power again
Fault display
FL not active
Trip again
Fault display
FL active
If the cause of tripping or that of
another failure is not yet removed.
E