What are the criteria for selecting the thickness of the sheet metal for the electrical distribution
The criteria for selecting the thickness of the sheet metal for the electrical distribution box cabinet are mainly
based on the following aspects:
### Type and Purpose of the Electrical Distribution Box
- **Lighting electrical distribution box**: It is usually used to control and distribute the lighting circuit. Its load is
relatively small, and the requirement for the strength of the cabinet body is relatively low. Generally speaking,
for lighting electrical distribution boxes and control boxes with a size greater than or equal to 600mm, 2.0mm
thick cold-rolled steel plates can be used, and for those less than 600mm, 1.5mm thick cold-rolled steel plates
can be used.
- **Power electrical distribution box**: It is mainly used to provide power distribution and control for power equipment
such as motors. Its load current is relatively large and may need to withstand relatively large electrodynamic and
mechanical stresses. Therefore, the thickness of the sheet metal of the cabinet body of the power electrical distribution box
is usually not less than 1.5mm. For some power electrical distribution boxes with large capacity or special requirements,
thicker sheet metal, such as 2.0mm or thicker, may be used.
- **Power distribution cabinet**: The power distribution cabinet is usually used to centrally control and distribute a relatively
large capacity of electrical energy, and has high requirements for the strength, stability, and protection performance of the
cabinet body. Generally, it is required that the thickness of the steel plate of the cabinet body shall not be less than 2.0mm
to ensure that the cabinet body can maintain good structural integrity and protection performance during long-term operation
and in case of possible faults such as short circuits.
### Size and Weight of the Electrical Distribution Box
- When the width of the electrical distribution box is greater than 500mm and less than 800mm, the thickness of the steel plate
should not be lower than 1.2mm; when the width is greater than or equal to 800mm, the thickness of the steel plate should
not be lower than 1.5mm. This is because a larger-sized electrical distribution box requires thicker sheet metal to ensure the
structural strength of the cabinet body and prevent deformation due to its own weight or the weight of the installed equipment.
- When the semi-perimeter of the household box body is ≥ 900MM, the thickness of the steel plate should not be less than
1.5mm, and when the semi-perimeter is < 900MM, the thickness of the steel plate should not be less than 1.2mm. For larger-sized
household boxes, using thicker sheet metal can ensure their stability and safety during installation and use.
### Installation Environment and Protection Requirements
- In an indoor environment that is dry and has less dust, the thickness of the sheet metal of the electrical distribution box cabinet
can be selected according to the general standard. However, if it is installed outdoors, in a humid environment, or in a place with
corrosive gases, in order to improve the protection performance of the cabinet body and prevent rust and corrosion, thicker sheet
metal should be selected, and corresponding anti-corrosion treatment measures should be taken, such as spraying anti-corrosion
paint and using galvanized steel plates.
- For electrical distribution boxes with high protection level requirements, such as IP54, IP65, etc., sheet metal with sufficient thickness
is required to ensure the tightness and strength of the cabinet body to meet the protection requirements. For example, in some
industrial sites where there is a lot of dust or where water splashing may occur, the thickness of the sheet metal of the electrical
distribution box cabinet may need to reach 2.0mm or even thicker, and at the same time, it should be matched with a good sealing
structure and materials to ensure that the electrical equipment inside the electrical distribution box is not affected by the external
environment.
### Electrical Performance Requirements
- For some electrical distribution boxes with requirements for electromagnetic shielding, such as in electronic equipment rooms,
hospitals, and other places, in order to prevent the electromagnetic interference generated by the electrical equipment inside the
electrical distribution box from affecting the normal operation of other equipment, or to prevent external electromagnetic interference
from affecting the performance of the equipment inside the electrical distribution box, sheet metal with certain electromagnetic
shielding performance may be selected, and it is necessary to ensure that the thickness of the sheet metal is sufficient to achieve
a good shielding effect. Generally speaking, in this case, steel plates with a thickness of not less than 2.0mm will be selected, and
corresponding shielding measures will be taken in the design of the cabinet body structure, such as adding a shielding layer and
reasonably arranging the grounding.
### Cost and Economy
- On the premise of meeting the usage requirements and safety standards of the electrical distribution box, cost is also one of the
factors to be considered when selecting the thickness of the sheet metal. Thicker sheet metal has a relatively higher price, which
will increase the manufacturing cost of the electrical distribution box. Therefore, when selecting the thickness of the sheet metal,
it is necessary to comprehensively consider the project budget and actual needs, and on the basis of ensuring quality and safety,
select a sheet metal thickness with high cost performance. For example, for some small-scale civil buildings or projects with strict
cost control, if the usage environment of the electrical distribution box is relatively simple and the load is small, a sheet metal with
a relatively lower thickness can be appropriately selected on the premise of meeting the relevant standards to reduce the cost.