1. Determine the following parameters of the circuit:
A Maximum working environment temperature b Standard working current c Maximum working voltage (Umax) d Maximum fault current (Imax)
2. Select a self restoring fuse element that can adapt to the maximum ambient temperature and standard operating current of the circuit
Use a temperature reduction {ambient temperature (℃) working current (A)} table and select the temperature that best matches the maximum ambient temperature of the circuit. Browse this column to view values that are equal to or greater than the standard operating current of the circuit.
3. Compare the maximum electrical rating of the selected component with the maximum operating voltage and fault current of the circuit
Use the electrical characteristic table to verify whether the components you selected in step 2 will use the maximum operating voltage and fault current of the circuit. Check the maximum operating voltage and maximum fault current of the device. Ensure that Umax and Imax are greater than or equal to the maximum working voltage and maximum fault current of the circuit.
4. Determine action time
The action time is the amount of time it takes to switch this component to a high resistance state when the fault current appears on the entire device. In order to provide the expected protection function, it is important to clarify the working time of the self restoring fuse element. If the component you choose acts too quickly, abnormal or harmful actions may occur. If the component moves too slowly, the protected component may be damaged before the component switches to a high resistance state.
Use a typical action time curve of 25 ℃ to determine whether the action time of the self recovery fuse element is too fast or too slow for the circuit. If so, return to step 2 to reselect the backup component.
5. Verify ambient operating temperature
Ensure that the minimum and maximum ambient temperature for the application is within the operating temperature range of the self restoring fuse element. The operating temperature range of most self-healing fuse components is between -40 ℃ and 85 ℃.
6. Verify the overall dimensions of the self restoring fuse element
Use the overall dimensions table to compare the overall dimensions of the self recovery fuse you have selected with the spatial conditions of the application.
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