thermistor motor protection relay, Protection Function: It protects motors from thermal overloads caused by high starting frequency, heavy starts, phase faults, insufficient cooling or high ambient temperatures., Sensor Inputs: It has an entrance for connecting up to 6 PTC resistors or bimetallic contacts in series., Working Principle: When the total resistance of the sensors reaches a specific threshold value (response value ≥ 3 kΩ), the output relay de-energizes (closed-loop operation)., Cable Break Detection:, Output Contacts: The ".12" model is specifically equipped with two changeover contacts (switches), Reset: Depending on the exact variant (e.g. with or without the suffix "/100"), it may include a thermal or electromagnetic reclosing (manual reset) lock, which requires manual intervention to reset the unit once, Auxiliary Voltage (Uh): The supply voltage varies depending on the specific part number (e.g. AC 42V, AC/DC 110-230V, etc.)