Sako SKI600, Manual

Page: 132 / 180

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Fig.FA-1 Motor Overload Protection Factor
In order to apply effective overload protection
to different kinds of motors, the motor
overload protection factor should be correctly
set to limit the Max.output current of the
driver. The factor is the percentage of motor
rated current to the rated output current of
the driver.
When the motor's power level matches the
driver, the protection factor can be set to
100%, as showed in Fig. FA-1.
FA.01
Motor overload protection factor
20.0％～ 120.0％
100.0%
When the power of VFD is larger than the
motor, in order to apply effective overload
p rote ct i o n to m oto rs w i t h d i f fe re n t
specification, the factor should be set correctly
as showed in Fig.FA-2.
The factor is calculated by the formula below:
Generally, the max. load current is the motors
rated current.
Fig. FA-2 Motor Overload
Protection Factor Setting
0: disabled
1: allowed (under voltage is seen as fault)
FA.02
Undervoltage protection action
0 ～ 1
0
FA.03
Undervoltage protection level
220V: 180 ～ 280V 200V
380V: 330 ～ 480V 350V
Depending
on model
This function code specifies the lower limit
of DC bus voltage when the driver operates
normally.
5JNF NJO
$VSSFOU
.PUPS0WFSMPBE
1SPUFDUJPO'BDUPS
NJO
I
$VSSFOU
5JNF
.PUPS0WFSMPBE
1SPUFDUJPO'BDUPS
4.2 Detailed Function Description
Since cooling conditions of common motor
deteriorates at low speed, the motors
thermal protection threshold should also
be adjusted. The "low speed" here refers to
the operating frequency lower than 30Hz,
with which the motor will be lowered of the
overload protection threshold.
2: variable frequency motor (thermal relay,
without low speed compensation)
The cooling effect of variable frequency
motor is not affected by the motors
speed, so low speed compensation is not
necessary.
= ×100%
allowed max. load current
inverter's rated output current
Motor Overload
Protection coefficient