What could lead to an overload tripping consistently in a motor?

Using an incorrect heater size in conjunction with a motor can indeed lead to overload tripping. This situation arises because the heater elements in overload relays are designed to protect the motor by tripping if the current exceeds a preset limit, indicating that the motor is experiencing excessive heating conditions. If the heater size is not matched properly to the motor's specifications (as outlined by NEMA standards), it may either trip too frequently or fail to trip when necessary, resulting in an unreliable protection system.

On the other hand, if the motor is functioning normally, there would be no reason for it to trip unnecessarily. Likewise, all settings being correctly calibrated means that the motor operates within expected ranges without causing overload conditions. Lastly, if there is no load on the motor, it should operate without tripping since the current draw is minimal, which further illustrates that incorrect heater sizing is a primary concern when considering consistent overload trips.