Functions Relating To Protections, Warnings And Various Output Signals5-110; Functions Relating To Protections, Warnings And Various Output Signals; Electronic Thermal Function - Omron SYSDRIVE MX2 SERIES User Manual

5-9 Functions Relating to Protections, Warnings and Various Output Signals

5-9 Functions Relating to Protections,
Warnings and Various Output Signals
The following explains the protective functions such as warning signals.

Electronic Thermal Function

This function calculates the rise in motor temperature in the Inverter based on the output current,
output frequency, motor characteristics and other data, to protect the motor against overheating.
Provides the most appropriate protection characteristics, taking into account the decline of the
motor cooling capability at a low speed.
Outputs an alarm before the electronic thermal trips.
The time limit characteristics of the electronic thermal vary depending on the setting of Heavy
Load/Light Load Selection (b049).
Electronic Thermal Level
Parameter
No.
b012/b212
Example 1) Heavy load setting
Alarm time (s)
60
3.0
0 109 % 150 % 200 %
Electronic Thermal Characteristics
Although only one type of electronic thermal characteristic curve is available each for heavy load and light load,
the frequency characteristics can be switched by Electronic Thermal Characteristics Selection (b013/b213).
A standard motor requires reduced load (current) because the lower the motor rotation speed
is, the lower the cooling capacity of its self-cooling fan gets. When the frequency drops, the
reduction multiple also decreases and the thermal level (current) drops, as well.
The reduced torque characteristics depend on the heat radiation of a standard motor.
Parameter
No.
b013/b213
SYSDRIVE MX2 Series USER'S MANUAL (3G3MX2-Axxxx)
Function name
Electronic Thermal Level 1/2
Motor current (A)
(ratio relative to b012/b212)
Function name
00: Reduced torque characteristics
Electronic
Thermal
01: Constant torque characteristics
Characteristics
Selection 1/2 02: Free setting
Data range
0.20 × Rated current to
1.00 × Rated current
Example 2) Light load setting
Alarm time (s)
60
0.5
0
116 % 120 % 150 %
Data
Default
Unit
setting
Inverter
rated A
current
Motor current (A)
(ratio relative to b012/b212)
Default
Unit
setting
01 −
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