YASKAWA GA700 Technical Manual page 90

2.19 Dynamic Braking Option, Motor Protection
Electronic thermal overload protection function: motor is protected by simulating the cooling ability of general-
purpose motors and forced-vented motors based on the relationship between speed and heat characteristics within
the variable speed control range.
When Operating Multiple Motors on a Single Drive
To disable the overload protection function of the electronic thermal protector of the drive, set L1-01 = 0 [Motor
Overload Protection Select = Disabled].
Note:
When operating multiple motors with a single drive, the electronic thermal protector of the drive cannot be applied.
Long Motor Cables
When a high carrier frequency and long motor cables are used, nuisance tripping of the thermal relay may occur
due to increased leakage current. To avoid this, reduce the carrier frequency or increase the tripping level of the
thermal overload relay.
Nuisance Tripping Due to a High Drive Carrier Frequency
Current waveforms generated by high carrier frequency PWM drives tend to increase the temperature in overload
relays. It may be necessary to increase the trip level setting when encountering nuisance triggering of the relay.
WARNING! Fire Hazard. Make sure that there isn't another cause triggering overload before raising the detection level of the
thermal relay. Adjust electrothermal settings only after verifying local ordinances for electrical wiring. Improper wiring may cause
a fire.
90 YASKAWA ELECTRIC SIEP C710617 01B YASKAWA AC Drive GA700 Technical Manual