Patent ID: 8767367

Claim:
A wire protection method of protecting a wire used for supplying electric power from a power source to a load, the method comprising the steps of: detecting an applied-current to the load every predetermined time; estimating a temperature of the wire, wherein the estimating includes: calculating a rise in temperature of the wire from a reference temperature based on heat generation and heat radiation of the wire due to the detected applied-current per the predetermined time; and adding the wire rise temperature to the reference temperature; determining whether the estimated wire temperature is lower than a predetermined upper limit temperature; newly estimating the wire temperature upon determination in the determining step that the estimated wire temperature is lower than the predetermined upper limit temperature, wherein the newly estimating includes: calculating a new rise in temperature of the wire from the reference temperature using the rise in temperature, the new rise in temperature based on the heat generation and the heat radiation of the wire due to a newly detected applied-current per the predetermined time; and adding the new wire rise temperature to the reference temperature; and stopping the electric power supply from the power source to the load upon determination in the determining step that the estimated wire temperature is equal to or higher than the predetermined upper limit temperature.