Hitachi WJ200-001S Instruction Manual page 133

348
Electronic Thermal Overload Alarm Setting
The thermal overload detection protects the inverter and motor from overheating due to
an excessive load. It uses a current/inverse time curve to determine the trip point.
First, use  to select the torque characteristic that matches your load. This allows
the inverter to utilize the best thermal overload characteristic for your application.
The torque developed in a motor is directly proportional to the current in the windings,
which is also related to the heat generated (and temperature, over time).
Therefore, you must set the thermal overload threshold in terms of current (amperes)
for parameter . The range is 20% to 100% of the rated current for each inverter
model. If the current exceeds the level you specify, the inverter will trip and log an event
(error ) in the history table. The inverter turns the motor output OFF when tripped.
Separate settings are available for the second motor (if applicable) as shown in the
following table.
Func.
Code
Level of electronic thermal

Level of electronic thermal,

2 nd motor
Electronic thermal

characteristic
Electronic thermal

characteristic, 2
Free setting electronic

thermal ~freq.1
Free setting electronic

thermal ~current1
Free setting electronic

thermal ~freq.2
Free setting electronic

thermal ~current2
Free setting electronic

thermal ~freq.3
Free setting electronic

thermal ~current3
WARNING: When parameter , level of electronic thermal setting, is set to motor
FLA rating (Full Load Ampere nameplate rating), the inverter provides solid state
motor overload protection at 115% of motor FLA or equivalent. If parameter 
exceeds the motor FLA rating, the motor may overheat and be damaged. Parameter
, level of electronic thermal setting, is a variable parameter.
"b" Function
Name
Set a level between 20% and 100%
for the rated inverter current.
Select from three curves, option
codes:
Reduced torque
Constant torque
Free setting
motor
nd
Range is 0 to 400Hz
Range is 0 to inverter rated current
Amps
Range is 0 to 400Hz
Range is 0 to inverter rated current
Amps
Range is 0 to 400Hz
Range is 0 to inverter rated current
Amps
Description
Run Defaults
Mode
Initial data Units
Edit
Rated A

current for
each
inverter
model *1
A

01 

01 

0.0 Hz

0.00 Amps

0.0 Hz

0.00 Amps

0.0 Hz

0.00 Amps
