YASKAWA E1000 Technical Manual page 210

5.8 L: Protection Functions
Setting 4: PM motor with variable torque
This setting is for operating a PM motor. PM motors for derated torque have a self-cooling design, so the overload
tolerance drops as the motor slows. Electronic thermal overload is triggered in accordance with the motor overload
characteristics, providing overheat protection across the entire speed range.
Overload Tolerance
150
120
100
80
Continuous
50
0.0
10 33
Motor Speed (%)
■
L1-02: Motor Overload Protection Time
Sets the time it takes the drive to detect 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 5.61 shows an example of the electrothermal protection operation time using a general-purpose motor operating
at 60 Hz 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.
Figure 5.61
■
Motor Protection Using a Positive Temperature Coefficient (PTC)
A motor PTC can be connected to an analog input of the drive. This input is used by the drive for motor overheat
protection.
When the PTC input signal reaches the motor overheat alarm level, an oH3 alarm will be triggered and the drive will
continue operation as selected in L1-03. When the PTC input signal reaches the overheat fault level, an oH4 fault will be
triggered, a fault signal will be output, and the drive will stop the motor using the stop method determined in L1-04.
210
60 s
100
Name
Motor Overload Protection Time
Operation time (minutes)
10
7
3
1
0.4
0.1
0 100
Figure 5.61 Motor Protection Operation Time
Cooling Ability
Motor is designed to produce 100% torque at base
speed. Built with effective cooling capabilities.
common_TMonly
Motor current (%)
150 200
E2-01 = 100% motor current
YASKAWA ELECTRIC SIEP C710616 35D YASKAWA AC Drive E1000 Technical Manual
Overload Characteristics
Reaching 100% when operating at below the base
frequency will cause a motor overload fault (oL1).
The drive fault output closes and the motor coasts to
stop.
Setting Range
0.1 to 5.0 minutes
Cold start
Hot start
Default
1.0 minutes