Distribution boxes are also known as the “commander” of household circuits, with primary duties of power distribution and security protection. But when faced with a variety of materials and complex functions of distribution boxes in the market, the majority of customers tend to be bewildered.
In this article, we will briefly outline the seven most important points for the choice of distribution boxes based on actual needs, professional standards, and purchasing experience, so you can make smart and practical decisions.
1.Choose the appropriate material and thickness
Metal shell: mainly cold-rolled steel plate, with high strength and good compressive strength. The fire-resistant properties of metal shell distribution boxes are very good, as its shell can effectively resist the threat of high temperature fire, so the metal shell distribution box selection is very suitable for high load or industrial environment.
Furthermore, metal casing can also provide more effective mechanical protection to protect the internal device from being damaged by external impact. These properties make it the choice material in high electrical load areas like factories, commercial buildings, etc.
Plastic casing (such as ABS or PC flame retardant material): Distribution boxes made of this type of material are lighter in weight, simpler to transport and install, and possess good insulation properties, which can effectively prevent current leakage and prevent electric shock to a certain extent. Due to the superior corrosion resistance, plastic can also provide good protection in wet conditions.
2.Calculate electricity demand and select appropriate capacity
The capacity of the distribution box should match the total power of the household to avoid situations where the capacity of the distribution box is too large and the total power of the household is insufficient, or vice versa. Correctly matching capacity can ensure the stable operation of the power system and avoid safety hazards caused by overload or insufficient capacity.
Circuit planning:
Small unit (4-12 routes): main air switch+room branch+air conditioning/water heater/kitchen dedicated
Medium to large unit (24 way): Need to consider expansion needs such as smart home and audio-visual systems
Main switch specifications:
It is recommended to choose a 40-63A bipolar circuit breaker for the main switch, which supports leakage protection
High power equipment such as air conditioners require separate 20-32A circuits to be configured
3.Selection of Security Protection Mechanisms
| Protection Function | Application Scenario | Recommended Configuration |
| Residual Current Device(RCD) | Socket circuit (kitchen/bathroom,etc.) | 30mA sensitivity, 0.1-second disconnection |
| Overload Protector | Main circuit/high-powerequipment | Circuit breaker matching the load current |
| Short Circuit Protector | Entire circuit | Switch with breaking capacity greater than 6kA |
| Surge Protector | Lightning-prone areas | Integrated SPD surge protector |
4.Brand and certification of distribution box
When choosing a distribution box, we not only need to consider the price of the distribution box, but also the brand and whether the product certification is qualified. We also know that if a product is too low compared to the market price, it may be a low-quality product, which can have a negative impact on the future use of the equipment and even require a lot of time and money for maintenance.
Firstly, it is necessary to choose branded products that have been certified by standards such as GB, IEC, UL, etc. These products are all power distribution boxes that have been internationally certified
Here are recommendations for strong brands with certificates
ONESTO,Schneider, Siemens ABB, stable performance, excellent technical support and after-sales service
The most cost-effective distribution box supplier – ONESTO. We offer high-quality products at both premium and affordable prices to meet the diverse needs of our customers. ONESTO offers a variety of specifications and material choices, and supports customized services. We also provide professional technical support and comprehensive after-sales service to ensure a worry free user experience for our customers.
Click to learn about distribution box products
5. Installation details and operations·
Here are some installation specifications and operations
Wiring specifications:
The neutral wire (N) and ground wire (PE) need to be separately connected to the busbar, and twisting is prohibited
The wire needs to be insulated with a conduit, and rubber sheaths should be added to the inlet and outlet of the wire
Installation location:
The open box is 1.2-1.5 meters above the ground, and a 20mm installation space is reserved for the concealed box
Avoid installation in damp, high temperature, or obstructed areas
6. Basic maintenance extends the service life
Check if the wiring terminals are loose every six months
Test the leakage protection function annually (press the TEST button to trip instantly)
Pay attention to moisture prevention inside the box during humid seasons, and use silicone desiccant for drying
Summarize
Choosing a distribution box is not about ‘bigger is better’, but about balancing safety, cost, and scalability based on the actual electricity needs of the household. It is recommended to jointly develop a power distribution plan with electricians in the early stage of decoration, and reserve 20% of redundant capacity to cope with future upgrades. Remember: a wise choice will build a ten-year defense line for safe electricity use for the family!
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