CIRCUIT FOR PREVENTING BURNING OUT AND FIRE CAUSED BY OVERHEATING BY BREAKING SWITCH IN OVERHEATING BY SENSING TEMPERATURE OF ENGINE IN PRE-HEATING OPERATION OF PRE-HEATING SYSTEM FOR EXCAVATOR

摘要

PURPOSE: A circuit for preventing burning caused by overheating in a pre-heating operation of a pre-heating system for an excavator is provided to prevent an engine of the excavator from being burned and to restrict a fire by detecting the temperature with an inner sensor according to an input pre-heating signal and stopping the pre-heating system by cutting off the circuit if over the constant temperature. CONSTITUTION: A circuit(1) for preventing burning caused by overheating in a pre-heating operation of a pre-heating system for an excavator is composed of a first relay(2) coupled to an external pre-heating signal line(7) to receive a signal through an external battery line(6); a second relay(3) linked to the first relay and coupled with the external pre-heating signal line; a heater unit(4) connected with the first relay and formed with a sensor for detecting the internal temperature; and a switch(5) for changing on/off operations according to the temperature detected by the heater unit between the second relay and the heater unit. The switch is turned off to shut off the circuit if the temperature is over a predetermined value by the heater unit in receiving a pre-heating signal through the external pre-heating signal line.