Correct selection of automobile fuse standards

1、 Fuses are classified according to their functions. At this time, the first letter represents the functional level, while the second letter represents the protected object.

1. 1st letter

A Local scope protection (backup protection fuse)

G Full range protection (general purpose fuse)

2. 2nd letter

G Cable and conductor protection (general application)

M Switch electrical protection (motor circuit protection)

R Semiconductor protection (used as rectifier protection)

L Cable and conductor protection (according to DIN VDE)

2、 1. Semiconductor protection within local scope of fuse aR (DIN VDE/IEC)

2. Fuse gR (DIN VDE/IEC) full range semiconductor protection

3、 In addition, the fuse is also marked with "slow action" and "fast action", which are stipulated in IEC/CEE/DIN VDE (DIN is the code of German standard, similar to the Chinese standard number with the word "GB" in front of it; VDE is the world's authoritative certification body, (short for "German Association of Electrical Engineers"), and they can issue their own safety standards, and the standards they issue are often adopted as German standards. When "VDE DIN" is placed before the German standard, it means that this standard is a German standard published by VDE. IEC is the International Electrotechnical Commission.

1. The "quick action" feature means that the breaking speed of the fuse under short circuit condition is faster than the working level gL/gG. The fuse link used in the DC railway power supply system is characterized by "slow action", which is especially suitable for breaking the DC current with large inductance.

2. The fast action and slow action characteristics of the fuse are also applicable to the protection of cables and conductors. The full range fuse (gL/gG, gR, fast action, slow action) can safely and reliably disconnect the overload current and short-circuit current. Local fuses can only be used for short circuit protection (aM, aR).

3. Letter introduction:

GL (DIN VDE)/gG (IEC) full range of cable and conductor protection

AM (DIN VDE/IEC) motor circuit protection in local scope

AR (DIN VDE/IEC) semiconductor protection in local scope

GR (DIN VDE/IEC) full range semiconductor protection

The correct choice should be the gR standard,