Hitachi WJ200-001L, Instruction Manual

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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.
“b” Function Run
Mode
Edit
Defaults
Func.
Code
Name Description Initial data Units

Level of electronic thermal Set a level between 20% and 100%
for the rated inverter current.

Rated
current for
each
inverter
model *1
A

Level of electronic thermal,
2
nd motor

A

Electronic thermal
characteristic Select from three curves, option
codes:


Reduced torque

 Constant torque

 Free setting

01



Electronic thermal
characteristic, 2
nd
motor

01



Free setting electronic
thermal ~freq.1 Range is 0 to 400Hz

0.0 Hz

Free setting electronic
thermal ~current1 Range is 0 to inverter rated current
Amps

0.00 Amps

Free setting electronic
thermal ~freq.2 Range is 0 to 400Hz

0.0 Hz

Free setting electronic
thermal ~current2 Range is 0 to inverter rated current
Amps

0.00 Amps

Free setting electronic
thermal ~freq.3 Range is 0 to 400Hz

0.0 Hz

Free setting electronic
thermal ~current3 Range is 0 to inverter rated current
Amps

0.00 Amps
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.