Hitachi SJ Series, User Manual

Page: 205 / 786

12-7-6
Chapter 12 Inverter Functions
12.7.2 Monitoring of motor
temperature
• Want to make thermal protection of motor
• Want to make temperature protection of the motor
using a thermistor resistance.
• The temperature protection of an external device
can be made by connecting a thermistor installed
in the motor or other external device to the inverter
and setting the function of the thermistor.
• The external thermistor should be wired between
the control terminals TH+ and TH-.
• Set the thermistor selection [Cb-40] and the
resistance level to cause an error [bb-70] in
accordance with the thermistor’s specifications.
• [E035] thermistor error occurs when the thermistor
resistance reaches the thermistor error level
[bb-70] depending on the motor temperature.
• When [Cb-40] is set to 02, [dA-38] motor
temperature monitor indicates the detected
temperature of the motor.
Parameters
• When an external thermistor is not connected, a
trip occurs if the thermistor selection [Cb-40] is set
to 01.
• To use this function, the wiring distance between
the motor and the inverter has to be 20 m or
shorter. Since the current flowing in the thermistor
is very weak, a measure such as wiring separation
should be taken to prevent noise from the motor
current.
• When [Cb-40] is set to a value other than 02,
[dA-38] motor temperature monitor indicates 0 °C.
Item Parameters Data Description
Thermistor
error level
[bb-70] 0~10000.( Ω )
Set the resistance for the temperature at which a
trip occurs in accordance with the thermistor
resistance specifications.
Effective when [Cb-40]=01, 02
Thermistor selection [Cb-40]
00 Disabled
01
Enabled Positive temperature coefficient resistor
(PTC)
02
Enabled Negative temperature coefficient resistor
(NTC)
Thermistor
adjustment
[Cb-41] 0.0~1000. Use as gain adjustment.
Motor temperature
monitor
[dA-38] -20.0~200.0(C°) Indicates the detected motor temperature.
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