Thermistor Thermal Protection - Hitachi SJ300 Series Instruction Manual

4–28
Using Intelligent Input Terminals
Thermistor
Thermal
Protection
Motors that are equipped with a thermistor can be protected from overheating. Input terminal
[TH] is dedicated to sense a thermistor resistance. The input can be set up (via B098 and B099)
to accept a wide variety of NTC or PTC type thermistors. Use this function to protect the motor
from overheating.
Opt.
Symbol Function Name
Code
— TH Thermistor Thermal
Protection
[TH] only
Valid for
inputs:
B098, B099, and C085
Required
settings:
Notes:
• Be sure the thermistor is connected to termi-
nals [TH] and [CM1]. If the resistance is
above or below (depending on whether NTC
or PTC) the threshold the inverter will trip.
When the motor cools down enough, the
thermistor resistance will change enough to
permit you to clear the error. Press the STOP/
Reset key to clear the error.
Input
Description
State
Sensor When a thermistor is connected between
to terminals [TH] and [CM1], the inverter
checks for over-temperature and will
cause a trip (E35) and turn OFF the output
to the motor
Open An open circuit in the thermistor causes a
trip, and the inverter turns OFF the output
Example:
TH
TH FW
8
P24 PLC CM1
thermistor
Motor
See I/O specs on page 4–9.
CM1
5 3 1
7 6 4 2