DIN is the German Industrial Standard. Using a guide rail is a mounting method for industrial electrical components. Electrical components that support this standard can be easily clamped onto the guide rail without the need for screws, and maintenance is also convenient. The commonly used guide rail width is 35mm.
Distribution boxes are usually installed in corridors or rooms. To prevent unauthorized access, they are typically equipped with a door, which is normally closed. Therefore, the loop measurement and metering instruments are usually installed inside the box rather than on the panel. Installing guide rail-type instruments inside the box saves space and is easy to operate. Hence, distribution box instruments are usually of the guide rail type. Traditionally used wall-mounted electric meters, which are large in size and inconvenient to install, have gradually been replaced by guide rail-type instruments. Guide rail-type instruments feature high measurement accuracy, strong overload capacity, stable and reliable performance, a wide operating voltage range, low power consumption, small size, light weight, and a modular structure. They have a wide range of applications and can be used wherever electrical energy metering is required, such as in buildings, shopping malls, convention and exhibition centers, schools, airports, ports, and factories.