Line maintenance is to maintain the wire and coordinate the maintenance of the circuit electrical equipment. The maintenance equipment mainly has fuses, circuit breakers and fusible wires. Gaoge Electronics.
1. Fuse selection criteria
Engine ECU, ABS, etc. have a great impact on the performance and safety of the whole vehicle. In addition, electrical equipment that is susceptible to other electrical equipment is necessary to have a single fuse. Engine sensors, various types of alarm lights and external lighting, speakers, etc. The equipment has a great influence on the performance and safety of the whole vehicle, but the electric load is not sensitive to each other. Therefore, this kind of electric load can be combined with each other according to the situation, and a fuse is used together.
The electrical load of the usual electrical equipment set for adding comfort can be combined with each other depending on the situation, and a fuse is used together.
The fuses are divided into fast-melting and slow-melting. The first component of the fast-acting fuse is the thin tin wire. The chip fuse is widely used in the layout, reliability, vibration resistance and easy detection. It is widely used. The device is actually a tin alloy piece, and the fuses of this layout are usually connected in series to a circuit of a rational load, such as a motor circuit.
Resistive type load and inductive type load should avoid using the same fuse as much as possible. Usually calculate and determine the fuse capacity according to the maximum connected working current of the electric equipment, according to the empirical formula: fuse extra capacity = maximum working current of the circuit ÷ 80 % (or 70%).
The biggest feature of the circuit breaker is its recoverability, but its cost is higher and it is less used. The circuit breaker is usually a thermo-mechanical device, which uses different thermal deformation of the two metals to open or close the contacts or self-connect them. The new type of circuit breaker uses PTC solid data as an overcurrent maintenance component, which is a positive temperature coefficient resistor that is disconnected or turned on according to the current or temperature. The biggest advantage of this maintenance component is that after the fault is removed Can be actively connected, no manual conditioning and replacement.