Toshiba TOSVERT VF-MB1 Instruction Manual page 68

[Parameter setting]
Title Function
Electronic-thermal memory

Overload alarm level

*1: The inverter's rated current is 100%. When  (current and voltage unit selection) = 1 (A (amps)/V
(volts)) is selected, it can be set at A (amps).
*2: f632 = 1 : Electronic-thermal statuses (cumulative overload value) of motor and inverter are saved when
power supply is OFF. It is calculated from the saved value when power supply is ON again.
*3: Parameter aul is displayed as "0" during reading after this is set.
Present setting of inverter overload characteristic can be confirmed by status monitor.
Refer to monitor "Overload and region setting" of section 8.2.1.
1) Setting the electronic thermal protection characteristics selection  and
motor electronic thermal protection level 1 , 2 
The electronic thermal protection characteristics selection  is used to enable or disable the motor
overload trip function (  ) and the overload stall function.
While the inverter overload trip (  ) will be in constantly detective operation, the motor overload trip
(  ) can be selected using the parameter 
Explanation of terms
Overload stall: This is an optimum function for equipment such as fans, pumps and blowers with
variable torque characteristics that the load current decreases as the operating speed
decreases.
When the inverter detects an overload, this function automatically lowers the output
frequency before the motor overload trip  is activated. With this function,
operation can be continued, without tripping, by operating using a frequency balanced
by load current.
Note: Do not use the overload stall function with loads having constant torque characteristics (such as
conveyor belts in which load current is fixed with no relation to speed).
[Using standard motors (other than motors intended for use with inverters)]
When a motor is used in the lower frequency range than the rated frequency, that will decrease the cooling
effects for the motor. This speeds up the start of overload detection operations when a standard motor is
used in order to prevent overheating.
Adjustment range
0: Disabled
1: Enabled *2
10-100
C-17
E6581697
Default setting
0
50
3