As modern electrical systems become more and more developed and improved, the use of junction boxes is becoming more and more popular. The use of electrical boxes is usually divided into commercial and residential use, and commercial electrical systems are often more stringent than residential systems.

So what are the uses of junction boxes in our current commercial applications? How to find a junction box that meets your application requirements? Next, we will discuss the commercial application of waterproof boxes based on some of their characteristics, such as size, material, protection level, printing trademarks, changing colors, etc. At the same time, we will also analyze some real customer cases of HIGHYI BOX..

What You Should Concern About Junction Box Used For Commercial Applications? 

The primary feature of a junction box is its protective function. The electrical enclosure of a junction box protects the wiring connections or devices inside it from harsh environmental conditions and accidental contact, such as electrical connection points, circuit boards, terminal connection devices, internal wiring of buttons, control devices, etc.
Because the internal components to be protected are very important and sensitive, we must emphasize that the quality of the junction box is critical for commercial applications. Fortunately, HIGHYI BOX can provide a variety of enclosure design solutions specifically for those customers who have questions about the commercial use of waterproof boxes.

What material is better ?Metallic vs. Plastic Junction Boxes

There are generally two types of materials for junction box shells on the market: metal (usually aluminum or stainless steel) or plastic (usually polycarbonate or ABS).

When considering waterproof boxes for commercial use, the material is the first point to consider. And this material depends on the cable and conduit materials you use. Metal sheathed cables, metal conduits or metal connectors, such as stainless steel connectors, brass nickel-plated connectors, usually need to be grounded with stainless steel junction boxes or aluminum boxes.

Plastic junction boxes are often a good match for non-metallic cables or plastic connectors.

HIGHYI BOX can provide metal and plastic junction boxes. Later we will introduce some advantages and disadvantages of these two types of junction boxes and the precautions for choosing the right one.

How to Choose a Right Size for a Junction Box ？

The size of the junction box itself is also a very important factor to consider, and we have already covered this in depth in our article on junction box sizes.

The size of the junction box itself is also a relevant factor in your selection. We cover this topic in depth in our junction box size guide, including the size specifications used by each country. Generally speaking, commercial junction boxes are larger and more demanding than residential ones because they contain more, more delicate, and more complex things.

In short, you need to consider the size of the junction box (or more accurately, the internal size, which takes into account the internal structure, such as the thickness of the junction box wall and the possible mounting posts). You can also refer to the NEC junction box size table to determine the appropriate enclosure size based on the number of conductors and the size of the installed components. Wire spacing also needs to be considered, because if wires are placed too close in space, it may cause interference with your system.

Determine the Volume Based on the Quantity and Size of Conductors

• Volume Requirements Corresponding to Different Wire Gauges: According to NEC 314.16, the volume size of the junction box needs to be determined based on the number and size of the conductors inside the box. For example, for a common 14 AWG conductor, each individual insulated conductor shall occupy 2 cubic inches of space; for a 12 AWG conductor, each shall occupy 2.25 cubic inches of space. If there are grounding conductors in the box, all the grounding conductors together shall occupy 2 cubic inches of space.
• Considering the Volume of Equipment and Fittings: In addition to the conductors, it is also necessary to consider the volume occupied by the equipment and fittings installed in the box, such as switches, receptacles, etc. For example, each switch or receptacle shall occupy 4 cubic inches or 4.4 cubic inches of space.

Other Important Features for Commercial Junction Boxes

1. IP Rating or NEMA Rating ？

Essentially, there is no difference between these two protection levels, but the regulations in different places are different. Generally speaking, IP Rating is more popular. They both evaluate the protection level and protection quality of electrical enclosures (including junction boxes). (For details, please read our previous article on NEMA and IP!).

If the requirements are very strict, please check the local commercial electrical regulations to find out whether NEMA or IP waterproof boxes are required.

2. Custom hole drilling.

If a waterproof box has no openings or access holes, it seems that the waterproof box is useless.
The reason is that the object protected by the waterproof box is most likely wires and cables. If you want to maintain the same protection level, you must install waterproof connectors, which requires opening holes in the waterproof box.

So the point to note is that if there are openings, you must install connectors with the corresponding protection level to maintain the protection level of the waterproof box.
HIGHYI ELECTRIC can provide professional, convenient and efficient CNC processing technology. You only need to send us accurate drawings and opening requirements, and we can easily help you realize the opening service. In addition, we provide a wide range of cable connection accessories to ensure that all accessories achieve the same protection level.

3. LOGO Printing or Labling

Generally, we can customize UV ​​printing of text and patterns required by customers according to their requirements. (Ultraviolet LED Inkjet Printer) Of course, these services require a certain fee, which is determined by the number of products and the content to be printed.

4. Hinged Covers

Some connection points need to be easily accessible to technicians for troubleshooting, especially junctions that supply power to critical system components. Enclosures with hinged covers make excellent junction boxes for these applications.

Fortunately, Polycase’s hinged enclosures give you these benefits without sacrificing security and protection. An enclosure with a hinged cover can still be waterproof and/or dustproof with the addition of a gasket seal on the door. For security, we include built-in lock hasps on our hinged enclosures to allow easy attachment of a padlock. 

5. Surface Mounting Hardware

Commercial junction boxes are usually mounted on walls or other flat surfaces, and you’ll need mounting hardware to attach the junction box securely. Mounting feet and flanges are some of the most common and practical ways to add mounting hardware to an electrical junction box. 

Some Polycase enclosure models come with mounting feet, flanges or other hardware already attached. In other cases, the buyer can equip the enclosure with a set of screw-on enclosure feet. If you choose an enclosure model that uses surface mounting accessories, make sure to purchase accessories that are designed to work with the model you’re using. 

6. UL 94 Flame Rating

A UL 94 flame rating measures a material’s ability to self-extinguish when exposed to an open flame. This can be a key characteristic for commercial junction boxes since it helps prevent electrical fires from spreading. The highest UL flame rating (UL 5VA) denotes a completely non-flammable box, while the lowest (UL H-B) slows the burn rate but does not self-extinguish completely. See our guide to UL 94 flame ratings for a full explanation.