Hitachi SJ Series User Manual page 205

Chapter 12
12.7.2 Monitoring of motor
temperature
Ｑ
• Want to make thermal protection of motor
• Want to make temperature protection of the motor
using a thermistor resistance.
Ａ
• 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
Item
Thermistor
error level
Thermistor selection
Thermistor
adjustment
Motor temperature
monitor
Parameters Data
[bb-70] 0~10000.(Ω)
00
01
[Cb-40]
02
[Cb-41] 0.0~1000.
[dA-38] -20.0~200.0(C°)
！
• 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.
Set the resistance for the temperature at which a
trip occurs in accordance with the thermistor
resistance specifications.
Effective when [Cb-40]=01, 02
Disabled
Enabled Positive temperature coefficient resistor
(PTC)
Enabled Negative temperature coefficient resistor
(NTC)
Use as gain adjustment.
Indicates the detected motor temperature.
12-7-6
Inverter Functions
Description