Operating Instructions

Descriptions of Parameter Settings
Descriptions of Parameter Settings
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● Setting the parameter to 1 is suitable for standard motor (motor fan is fixed on the rotor shaft). For this kind of
motor, the cooling capacity is lower in low speed; therefore, the action of an electronic thermal relay reduces
the action time to ensure the life of motor.
● When the power is cycled frequently, if the power is switched OFF, the electronic thermal relay protection is
reset; therefore, even setting the parameter to 0 or 1 may not protect the motor well. If there are several motors
connected to one drive, install an electronic thermal relay in each motor.
Pr.
Explanation
Settings
Default
14-81
Electronic thermal relay action
time 3 (motor 3)
30.0 to 600.0 sec.
60.0
14-83
Electronic thermal relay action
time 4 (motor 4)
30.0 to 600.0 sec.
60.0
● Set the parameter to 150% of motor rated current and use with the setting of Pr.14-81 and Pr.14-83 to prevent
motor damage due to overheating. When it reaches the setting, the drive displays EoL3 / EoL4, and the motor
coasts to stop.
● Use this parameter to set the action time of the electronic thermal relay. It works based on the I2t characteristic
curve of electronic thermal relay, the output frequency and current of the drive, and the operation time to
prevent the motor from overheating.
The action of the electronic thermal relay depends on the settings for Pr.14-80 and Pr.14-82
1. Pr.14-80 or Pr.14-82 is set to 0 (using inverter motor):
When the output current of the drive is higher than 150% of the motor rated current (refer to the motor rated
current % corresponded to the motor rated frequency in the motor cooling curve with independent fan), the
drive starts to count the time. The electronic thermal relay acts when the accumulated time exceeds Pr.14-81 or
Pr.14-83.
2. Pr.14-80 or Pr.14-82 is set to 1 (using standard motor):
When the output current of the drive is higher than 150% of the motor rated current (refer to the motor rated
current % corresponded to the motor rated frequency in the motor cooling curve with shaft-fixed fan), the drive
starts to count the time. The electronic thermal relay acts when the accumulated time exceeds Pr.14-81 or
Pr.14-83.
The actual electronic thermal relay action time adjusts according to the drive output current (shown as the
motor loading rate %). The action time is short when the current is high, and the action time is long when the
current is low. Refer to the following diagram.