YASKAWA AC Drive-A1000 Technical Manual page 240

5.8 L: Protection Functions
Overload Tolerance
Instantaneous rating (60 s)
150
125
115
100
83
77
67
0 0.2
Percent of base speed (%)
Setting 6: General-purpose motor (50 kHz)
Because the motor (50 kHz) is self-cooled, the overload tolerance drops when the motor speed is lowered. The drive
appropriately adjusts the electrothermal trigger point according to the motor overload characteristics and protects the motor
from overheat throughout the entire speed range.
Overload Tolerance
A: Max. speed for 200LJ and above
B: Max. speed for 160MJ to 180 LJ
C: Max. speed for 132MJ and below
n L1-02: Motor Overload Protection Time
Sets the detection time of motor overheat due to overload. This setting rarely requires adjustment, but should correlate with
the motor overload tolerance protection time for performing a hot start.
No.
L1-02
Defaulted to operate with an allowance of 150% overload operation for one minute in a hot start.
Figure 5.87 illustrates an example of the electrothermal protection operation time using a general-purpose motor operating at
the value of E1-06, Motor Base Speed, with L1-02 set to one minute.
During normal operation, motor overload protection operates in the area between a cold start and a hot start.
• Cold start: Motor protection operation time in response to an overload situation that was suddenly reached when starting a
stationary motor.
• Hot start: Motor protection operation time in response to an overload situation that occurred during sustained operation at
rated current.
240
Motor is designed to effectively cool
itself at speeds near 0.2% of base
speed.
100 120 130 150
Motor designed to operate from line
power. Motor cooling is most effective
when running at rated base frequency
(check the motor nameplate or
specifications)
Name
Motor Overload Protection Time
YASKAWA ELECTRIC SIEP C710616 31B YASKAWA AC Drive – A1000 Technical Manual
Cooling Ability
Cooling Ability
Setting Range
0.1 to 5.0 minutes
Overload Characteristics
Continuous operation with 100% load
from 0.2% to 100% of base speed.
Overload Characteristics
Continuous operation at less than line
power frequency with 100% load can
trigger motor overload protection
(oL1). A fault is output and the motor
will coast to stop.
Default
1.0 minutes