External thermal relay operation

What does E.OHT mean?

If an external thermal relay (for motor overheat protection) or an internally mounted motor temperature relay switches on (contacts open), the inverter output is stopped. This function is activated only when the OH signal (value 7) is assigned to any of Pr. 180 to Pr. 186. The inverter requires a manual reset even if relay contacts automatically reset.

1. 1

   Verify the motor for signs of overheating; measure motor surface temperature if possible.

2. 2

   Check the operational status of the external thermal relay or motor temperature relay (its contacts should be closed during normal operation).

3. 3

   Verify that the value "7" (OH signal) is correctly set in one of the input terminal function selection parameters Pr. 180 to Pr. 186.

4. 4

   Reduce the mechanical load on the motor and review its operating duty cycle.