Motor Thermal Overload Management
Overview
The drive includes an internal Motor Thermal Overload Protection (I²t) function which continuously monitors motor load and estimates motor temperature.
The protection model uses the motor rated current entered in P-08 together with the settings in P-60.0, P-60.1, and P-60.2 to protect the motor from overheating. If the thermal overload limit is reached, the drive can either trip or automatically reduce the motor current, depending on the selected configuration.
Before You Begin
Ensure the motor rated current has been entered correctly in P-08.
Verify all motor nameplate data has been entered correctly.
Note
The thermal protection model uses the motor rated current (P-08) as its reference point.
Configure Motor Thermal Overload Retention
Use this setting to determine whether the motor thermal state is retained when power is removed.
Navigate to P-60.0 Thermal Overload Retention.
Select the required setting:
0 = Disabled – Thermal memory is cleared when power is removed.
1 = Enabled – Thermal memory is retained when power is removed.
Note
When enabled, the drive retains the calculated motor thermal state after mains power is removed, preventing a motor from being restarted before it has cooled.
Configure the Overload Reaction
Select how the drive should respond when the motor thermal limit is reached.
Navigate to P-60.1 Thermal Overload Reaction.
Select the required setting:
0 = I.t-trP Trip
When the thermal overload accumulator reaches its limit, the drive trips on I.t-trP to prevent motor damage
1 = Current Limit Reduction
When the thermal overload accumulator reaches 90%, the drive automatically limits output current to 100% of the motor rated current (P-08).The original current limit setting is automatically restored when the thermal overload accumulator falls below 10%.
Configure the Motor Overload Factor
The Motor Overload Factor determines the current level at which the thermal overload accumulator begins to increase.
Navigate to P-60.2 Motor Overload Factor.
Set the required overload factor between 50% and 150%.
Example
If :
P-08 Motor Rated Current = 10 A
P-60.2 = 100%
The thermal model begins accumulating overload when motor current exceeds 10 A
If :
P-08 Motor Rated Current = 10 A
P-60.2 = 110%
The thermal model begins accumulating overload when motor current exceeds 11 A.
Note
The overload threshold cannot exceed the drive rated current. An internal protection limit automatically applies.
Display and Indicators
Display | Description |
|---|---|
OvLd | Motor Overload Warning |
I.t-trP | Motor Thermal Overload Trip |
Troubleshooting & FAQs
Problem/Question | Solution/Answer |
|---|---|
I.t-trP trip occurs during normal operation | Reduce motor load |
I.t-trP trip occurs unexpectedly | Verify P-08 motor rated current |
Frequent overload warnings | Review P-60.2 setting |
Drive current limits unexpectedly | Check P-60.1 configuration |
Trip remains after power cycle | Allow motor to cool or disable P-60.0 |
Should P-08 be increased instead of P-60.2? | No. P-08 should always match the motor nameplate current. Use P-60.2 if a different overload factor is required. |