Delta VFD300C43S-HS User Manual page 373

and motor speed. Therefore, the action of electronic thermal relays remains stable in low speed
to ensure the load capability of the motor in low speed.
 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.
Electronic Thermal Relay Action Time 1 (Motor 1)

Electronic Thermal Relay Action Time 2 (Motor 2)

Settings
 Set the parameter to 150% of motor rated current and use with the setting of Pr.06-14 and
Pr.06-28 to prevent motor damage due to overheating. When it reaches the setting, the drive
displays "EoL1 / EoL2", and the motor free runs to stop.
 Use this parameter to set the action time of the electronic thermal relay. It works based on the I
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 electronic thermal relay depends on the setting for Pr. 06-13 and Pr. 06-27.
1. Pr. 06-13 or Pr. 06-27 set to 0 (using inverter motor):
When the output current of motor drive is higher than 150% of motor rated current (refer to the
motor cooling curve with independent fan), motor drive starts to count the time. The electronic
thermal relay acts when the accumulated time exceeds Pr. 06-14 or Pr. 06-28.
2. Pr. 06-13 or Pr. 06-27 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 cooling curve with shaft-fixed fan), the drive starts to count the time. The electronic
thermal relay acts when the accumulated time exceeds Pr. 06-14 or Pr. 06-28.
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 chart: (The motor cooling
curve with shaft-fixed fan and motor cooling curve with independent fan F = 50 Hz are the
same one.)
30.0–600.0 sec.
12.1-06-7
Chapter 12 Description of Parameter SettingsC2000-HS
Default: 60.0
2 t