Absolute Maximum Current

The Absolute Maximum Current, often shortened to ABS Max Current or ABS Current, is a protection limit used by the controller to prevent excessive phase current.

If the measured phase current exceeds this value, the controller will trigger the FAULT_CODE_ABS_OVER_CURRENT fault to protect the controller, motor, and power stage from potential damage.

ABS Max Current is a hardware protection limit and is not a tuning parameter. It should never be increased simply to make over-current faults disappear. Raising the limit without understanding the cause of the fault can result in overheating, damaged MOSFETs, damaged motor windings, or unsafe operating conditions.

If a controller repeatedly triggers FAULT_CODE_ABS_OVER_CURRENT, the underlying cause should be investigated and corrected. Common causes include:

• Incorrect motor parameters
• Observer instability
• Poor current sensor readings
• Mechanical binding or sudden load changes
• Current limits that are too aggressive for the system
• Hardware faults
• Wiring issues
• Excessive motor inductance or resistance estimation errors

⚠️ Absolute Maximum Current is not the same as Motor Current Max. Motor Current Max is a user-configurable operating limit used during normal operation, whereas ABS Max Current is an emergency protection threshold designed to prevent hardware damage. Under normal operating conditions, the controller should rarely, if ever, reach the ABS Max Current limit.

Example

A controller may be configured with:

• Motor Current Max: 300A
• ABS Max Current: 450A

During normal operation, the controller attempts to remain within the configured motor current limits. If a fault condition causes the measured phase current to exceed 450A, the controller will trigger FAULT_CODE_ABS_OVER_CURRENT and shut down the output stage to protect the hardware.

In simple terms: ABS Max Current is the controller’s emergency over-current safety limit and should be viewed as a protection setting rather than a performance setting.