Monitoring Motor Temperature - Hitachi WJ Series User Manual

Chapter 9
9.10.7

Monitoring Motor Temperature

 How to provide thermal protection for the motor?
Q
 How to use the resistance of the thermistor in the motor to provide temperature protection?
 A thermistor installed in the motor and other external devices can be wired to the inverter and
A
set to function to provide temperature protection for external devices.
 An external thermistor should be wired between the input terminal [5] and [L]. At this time,
assign an "External thermistor [PTC] (19)" to the input terminal [5]. When assigning [PTC], the [L]
terminal is the common terminal regardless of the sink/source logic.
 If the resistance of the PTC thermistor becomes approximately 3 kΩ or more, a "Thermistor error
[E35]" occurs. To fine-tune the resistance value that generates [E35] or to change the
temperature setting for generating an error according to the characteristics of the thermistor
used, adjust the value of "Thermistor gain adjustment [C085]".
 Use twisted wires for wiring the [PTC] terminal and [L] terminal of the external thermistor to
!
separate from other [L] common wires. The wiring distance should be within 20 m. For wiring,
also refer to "5.4 Control Circuit Terminal".
 Since the current flowing in the thermistor is small, consider separation of wiring to avoid noise
caused by motor current, etc.
Code
Input terminal [5]
[C005]
function
Thermistor gain
[C085]
adjustment
Item
External thermistor [PTC]:
A PTC thermistor can be wired to [PTC] terminal
and inverter can detect the temperature of the
motor and other external devices.
This allows for fine-tuning the setting of "Thermistor
error [E35]" for the operation resistance value of the
connected thermistor.
To trip the inverter with the PTC thermistor's
resistance value smaller than 3 kΩ, increase the value
of this setting.
To trip the inverter with the PTC thermistor's
resistance value greater than 3 kΩ, decrease the value
of this setting.
9-10-7
Description
Inverter Functions
Data
19
0.0 to 200.0 (%)