Delta VFD4A8ME21ANNAA User Manual

Chapter 12 Description of Parameter SettingsME300
12.1-06-7

Electronic Thermal Relay Selection 1 (Motor 1)

Electronic Thermal Relay Selection 2 (Motor 2)
Default: 2
Settings 0: Inverter motor (with external forced cooling)
1: Standard motor (motor with fan on the shaft)
2: Disable
 Prevents self-cooled motor from overheating under low speed. Use an electronic thermal relay to
limit the drive’s output power.
 Setting the parameter to 0 is suitable for an inverter motor (motor fan using an independent
power supply). For this kind of motor, there is no significant correlation between cooling capacity
and motor speed. Therefore, the action of electronic thermal relays remain 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)
Default: 60.0
Settings 30.0–600.0 sec.
 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 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.
40
20
60
80
100
2 5 50 10 0 1 50
Motor rated
frequency %
75
125
M
o
t
o
r
r
a
t
ed
current %
Motor cooling curve with shaft-fixed fan
25 5 0 100 1 50
40
20
60
80
10 0
M
o
t
o
r
r
a
t
ed
current %
Motor rated
frequency %
Motor cooling curve with independent fan
125
75
 The action of the electronic thermal relay depends on the settings 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 the drive is higher than 150% of motor rated current (refer to 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.06-14 or Pr.06-28.

Delta VFD4A8ME21ANNAA Specifications

General

Brand	Delta
Model	VFD4A8ME21ANNAA
Category	DC Drives
Language	English