Toshiba TOSVERT VF-A7 Instruction Manual page 92

[Example of setting: VF-A7 2007PL with a 0.4 kW motor (rated current: 2A)]
Key operated LED display
MON
ENT
ENT

ENT
[VF motor (motor intended for use with an inverter)]
Setting the electronic thermal protective function 
Set value Overload protection




VF motors (intended for use with an inverter) can be operated in lower frequency
ranges than general-purpose motors. If a VF motor is operated in an extremely low
frequency range, however, its cooling efficiency drops. In such a case, set the OL
reduction start frequency parameter  according to the characteristics of the
motor. (See the figure below.)
As a guide, it is advisable to set this parameter around the default value (VF motor 6Hz).
Title
Overload reduction start-up

frequency
Note)  is enabled when  is set at , , , or .
Setting the motor overload protection level #1
When the inverter is used for a motor with a capacity or a current rating smaller than that of the
inverter, it is necessary to adjust the motor overload protection level #1 parameter 
according to the rated current of the motor.
When the output current is displayed in %,100% corresponds to the rated output current of the inverter.
Output current reduction rate [%]
Setting of motor overload start level
The running frequency is displayed. (Make this setting when the
 motor is out of operation.)(If the monitor display mode setting
parameter  is set at [Running frequency])
Press the MON key to call up the first basic parameter

(automatic acceleration/deceleration).
Switch to (extended parameters of from  to

) by pressing the
Press the Enter key to call up the parameter 

(electronic thermal motor protection level 1).
Press the Enter key to display the parameter setting (set

value). (Default setting:  %)
Change the parameter setting to
 = (motor's rated current/inverter's rated output

= 2.0/5.0 x 100)
Press the Enter key to save the change. Then, 
and the set value are displayed alternately.
Overload stall
protect not stall
protect
not protect not stall
not protect
Function
1.0

0.6

E-26
Operation
or
current) x 100
stall
stall
Adjustment range
  [Hz]

6.0

key.
Default setting

Output frequency [Hz]