TM395: Thermistor Trip Relay

            Thermistor Trip Relay TM395 This device protects electrical equipment-such as motors and transformers-from damage caused by excessive temperatures (over-temperature conditions) by operating in conjunction with a PTC thermistor sensor. PTC sensors exhibit low resistance when the temperature is below the nominal operating temperature; however, when the temperature exceeds this threshold, the resistance increases sharply. Since PTC sensors are available in various types based on their nominal operating temperatures, the specific sensor selected determines the temperature at which the relay activates. The TM395 supports the use of two PTC sensor sets and operates as follows:

1. When the temperature of PTC1 is below the nominal operating temperature, Relay K1 turns ON; however, when the temperature exceeds this level, the relay turns OFF. When the temperature subsequently drops below the nominal operating temperature, the relay turns ON if the TM395 is in Auto Reset mode; if it is in Manual Reset mode, the Reset button must be pressed to turn the relay ON. Additionally, if the PTC sensor experiences a short circuit or an open circuit, the relay turns OFF.
    
2. When the temperature of PTC2 falls below the nominal operating temperature, Relay K2 turns OFF; when the temperature rises above the nominal operating temperature, Relay K2 turns ON. When the temperature subsequently drops below the nominal operating temperature, Relay K2 turns OFF; however, a switch-off delay can be configured for Relay K2. If this delay function is enabled, Relay K2 will not turn OFF until the set time has elapsed (selectable options: 5, 10, or 20 minutes). Relay K2 is suitable for connection to alarm systems or cooling fans.