Hitachi SJ300 Series Thermal, Thermistor, Protection

4–28

Using Intelligent Input Terminals

ThermistorThermalProtection

Operations and Monitoring

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

Input

Description

Code

State

—

TH

Thermistor Thermal

Sensor

When a thermistor is connected between

Protection

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

Valid for

[TH] only

Example:

inputs:

Required

B098, B099, and C085

TH

settings:

TH

FW

8

CM1

5

3

1

Notes:

P24

PLC

CM1

7

6

4

2

• 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/

thermistor

Reset key to clear the error.

Motor

See I/O specs on page 4–9.