Hitachi CONVENTION 14 Instruction Manual page 117

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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 B013 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 B012. The range is 20% to 120% 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 E05) 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
B012 Level of electronic thermal
setting
E-THM LVL
B212 Level of electronic thermal
setting, 2nd motor
2ETHM LVL
B013 Electronic thermal
characteristic
E-THM CHAR
B213 Electronic thermal
characteristic, 2nd motor
2ETHM CHAR
WARNING: When parameter B012, 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 B012
exceeds the motor FLA rating, the motor may overheat and be damaged. Parameter
B012, level of electronic thermal setting, is a variable parameter.
"B" Function
Name /
SRW Display
Set a level between 20% and
100% for the rated inverter
current.
001.60A
Set a level between 20% and
100% for the rated inverter
current.
001.60A
Select from three curves, option
codes:
00 Reduced torque 1
01 Constant torque
CRT
02 Reduced torque 2
Select from three curves, option
codes:
00 Reduced torque 1
01 Constant torque
CRT 02 Reduced torque 2
Torque
Constant torque
100%
80%
60%
Reduced
torque1
B013 = 00
0
5 20
Output frequency
Description
B013 = 01
Reduced
torque2
B013 = 02
Hz
60 120
Run Defaults
Mode
-FE -FU
Units
Edit (EU) (USA)
Rated A
current for
each inverter
model *1
A
01 01
01 01