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Thermistor Thermal Protection

Motors that are equipped with a thermistor can be protected from overheating. Input terminal [5] has the unique ability to sense a thermistor resistance. When the resistance value of the thermistor connected to terminal [TH] (5) and [L] is more than

3 k Ω ±10%, the inverter enters the Trip Mode, turns OFF the output to the motor, and indicates the trip status E35. Use this function to protect the motor from overheating.

Option

Terminal

Function Name

State

Description

Code

Symbol

 

 

 

19

TH

Thermistor Thermal Protection

ON

When a thermistor is connected to terminals [5]

 

and [L], the inverter checks for over-temperature

 

and will cause trip (E35) and turn OFF the output

 

to the motor

OFF

An open circuit in the thermistor causes a trip,

 

and the inverter turns OFF the output

Operations and Monitoring

Valid for inputs:

C005 only

Required settings

(none)

Notes:

 

Be sure the thermistor is connected to terminals [5] and [L]. If the resistance is above 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.

Example (requires input configuration— see page 3–49):

TH

 

 

 

 

 

 

 

5

4

3

2

1

L

PCS

P24

 

 

Motor

 

 

 

 

 

 

thermistor

 

 

 

 

NOTE: The trip level is hardware wise fixed and cannot be changed.

Page 163
Image 163
Hitachi X200 Series instruction manual Thermistor Thermal Protection, Valid for inputs C005 only