YASKAWA GA800 Technical Reference page 297

The overload tolerance decreases as motor speed decreases because the cooling fan speed decreases and the ability of
the motor to cool decreases in the low speed range.
The overload tolerance characteristics of the motor change the trigger point for the electronic thermal protector. This
provides motor overheat protection from low speed to high speed across the full speed range.
Load Tolerance
5 : PM Constant Torque
Use this setting with a PM motor for constant torque that has a speed range for constant torque of 1:500.
The speed control for this motor is 0.2% to 100% when at 100% load. Operating slower than 0.2% speed at 100%
load will cause motor overload.
Load Tolerance
6 : Variable Torque (50Hz)
Use this setting for general-purpose motors with a 50 Hz base frequency.
The overload tolerance decreases as motor speed decreases because the cooling fan speed decreases and the ability of
the motor to cool decreases in the low speed range.
The overload tolerance characteristics of the motor change the trigger point for the electronic thermal protector. This
provides motor overheat protection from low speed to high speed across the full speed range.
Load Tolerance
YASKAWA SIEPC71061737D GA800 Drive Technical Reference
Cooling Capability
This motor is designed to withstand increased temperatures
during continuous operation at rated speed and rated torque.
Cooling Capability
This motor is designed to withstand increased temperatures
during continuous operation in the low speed range (0.2%
base frequency).
Cooling Capability
This motor is designed to operate with commercial line
power. Operate at a 50 Hz base frequency to maximize the
motor cooling ability.
5.3 UL Standards
Overload Characteristics
(at 100% motor load)
If the motor operates continuously at lower speed than rated
rotation speed at more than 100% torque, the drive will
detect oL1. The drive triggers a fault relay output and the
motor coasts to stop.
Overload Characteristics
(at 100% motor load)
The motor operates continuously at 0.2% to 100% rated
speed. Operating slower than 0.2% speed at 100% load will
cause motor overload.
Overload Characteristics
(at 100% motor load)
If the motor operates at frequencies less than commercial
line power, the drive will detect oL1. The drive triggers a
fault relay output and the motor coasts to stop.
5
297