Toshiba TOSVERT VF-S15 Instruction Manual page 22

f344
: Lowering torque bias multiplier
The torque bias value at brake release is set by f342 (Load portion torque input selection).
When winding down, the torque bias value is multiplied by this parameter value.
Usually, a necessary torque in winding down is decreased by squaring the mechanical
efficiency.
The hoisting torque bias in winding down at 80% machine efficiency is 0.8*0.8=0.64 (about
60%).
Usually, set f344 = 60 to 70.
f345
: Brake release time
The brake release request signal is output at the same time outputting the set torque after the
starting signal is turned on.
After the time set with f345 (Brake release time), the inverter accelerates.
(*1)This parameter is roughly adjusted by executing f348 (Braking time learning function).
f346
: Creeping frequency
After run command is OFF, braking request is put out after decelerated to f346 (Creep
frequency). A standard setting of the creep frequency is about motor rated slips. For example,
in case of 5% slips in 60Hz motor, the creeping frequency is "60Hz*5%=3Hz".
(*1)This parameter is roughly adjusted by executing f348 (Braking time learning function) .
f347
: Creeping time 2
After run command is OF, braking request is put out after decelerated to f346 (Creep
frequency). Then, the creeping frequency is maintained for the time set with f347 (Creeping
time 2).
(*1)This parameter is roughly adjusted by executing f348 (Braking time learning function)
f348
: Braking time learning function
The brake learning function is executed by forward winding up operation after setting f348
(Braking time learning function) to 1.
Braking time learning function roughly adjusts the parameters f345 (Brake release time),
f346 (Creeping frequency), and f347 (Creeping time 2).
 Torque bias function (f342 to f344)
With this function, the motor produces enough
torque balanced with the load portion for the
opposite side before the brake is released, which
enables smooth start of the load.
<Selection of external signals>
Voltage signals
Current signals
VIA-CC – 0-10V (0-250%)
VIB-CC – 0-±10V (-250-250%)
VIC-CC – 4(0)-20mA (0-250%)
２１
Tension torque bias
as additional torque
Additional torque
(fixed direction)

1
2

E6581871
Reverse run
Forward run