Skip to main content

E4 Help Desk

Motor Thermistor Protection

The drive support Motor Thermistor connection that can either generate a warning or trip the drive if the motor temperature exceeds a safe operating limit.

Both PTC and KTY motor thermistors are supported and can be connected to Analog Input 1 (DA4) or Analog Input 2 (DA3).

Electrical Connection

Electrical connection for a PTC thermistor

PTC_wiring.svg

Connect Between terminals 24V and DA3

Electrical connection for a KTY thermistor

KTY.svg

Connect Between terminals 10V and DA3

Note

The wiring example shown uses Analog Input 2 (DA3). To use Analog Input 1, connect the thermistor to DA4 instead.

Configuring Motor Thermistor Protection

To configure a motor thermistor connected to Analog Input 2 (DA3):

  1. Select a Macro

    Set parameter P-15 to a macro that includes the E-TRIP function (for example, Macro 3).

    Note

    If none of the standard macros meet your requirements, use the freed-off terminal input function to assign the necessary input functions manually.

    When using a PTC Thermistor the default trip value is 2500Ω and 1900Ω for reset level.

  2. Set the thermistor type in parameter P-47.0 to define Analog input 2 (DA3) as the thermistor input.

    Note

    For a PTC thermistor set Ptc-th or for a KTY thermistor set ty-th.

Fault Code

No.

Display Message Description

Corrective Action / Further Information

F-Ptc

21

Motor PTC Over Temperature

The connected motor PTC device has caused the drive to trip.

F-tY

57

Motor KTY84 Over Temperature

The connected motor KTY device has caused the drive to trip.

SC-th

27

Motor thermistor short circuit

Check motor thermistor for wiring faults, check thermistor has not failed.

Question

Answer

Why is the drive not showing the correct fault code?

Check the analog input is configured for the correct thermistor type.

Check the selected macro in P-15 includes the E-TRIP function.

How can I monitor the thermistor resistance?

The measured thermistor resistance can be viewed using:

  • P0-45 – Analog Input 1 (DA4)

  • P0-46 – Analog Input 2 (DA3)

For a PTC thermistor, what are the trip and reset resistance values ?

  • Trip level : 2500Ω

  • Reset level : 1900Ω