Waterproof junction box, also known as cable junction box, is made of PC material, with high strength and elasticity coefficient, high impact strength, and a wide temperature range of use; High transparency and free staining; Low forming shrinkage, good dimensional stability, and surface gloss; Excellent aging resistance; Excellent weather resistance environment; Excellent electrical characteristics; Odorless and odorless, which is harmless to human health and safety. The prices of waterproof junction boxes on the market range from a few yuan to a few tens of yuan, with some cheap ones costing only around 8 yuan, while the expensive ones can cost over 80 yuan. This is related to factors such as the material, design, and brand of the waterproof junction box. The price of waterproof junction boxes with better materials and more inlet and outlet wiring ports is higher. The average price of products from well-known brands is about 10 yuan higher than that of ordinary brands. Considering the cost-effectiveness, it is recommended to choose products from top domestic brands, which have good functionality and are cost-effective. For example, Shenzhen Greenway Electronics Co., Ltd. has a relatively high cost-effectiveness for their waterproof junction boxes, and the product quality is also very good.
Next, we will introduce the factors that affect the layout of the incoming and outgoing lines of waterproof junction boxes. For non-standard waterproof junction boxes, the number of connection terminals, current carrying capacity, size, and installation method are generally determined based on the electrical wiring diagram. Then, plastic waterproof boxes or cast aluminum waterproof boxes with suitable appearance and internal space are selected as shells, Then fix the terminal assembly on the bottom plate of the casing or on a prefabricated threaded (or self tapping screw hole) boss, and finally process through holes on the thin-walled surface (usually four sides) of the casing that match the incoming and outgoing cables (actually considering the specifications of waterproof joints).
The factors that affect the layout of incoming and outgoing lines in waterproof junction boxes include:
(1) Waterproof joint main body wrench buckle or internal locking nut
The incoming and outgoing cables of the waterproof junction box are tightened inward through the forcing nut of the waterproof joint (also known as the waterproof lock head), causing the internal sealing rubber ring to hold tightly and achieve the sealing effect. Each waterproof joint model corresponds to a range that can pass through the outer diameter of the cable (such as the passing range of the PG7 waterproof joint) Φ 3-6.5mm), therefore the model of the waterproof joint must match the cable of each cable outlet, otherwise there may be situations where the cable cannot be connected or locked tightly. Generally speaking, there are two ways to install waterproof joints and junction boxes: one is to pre prepare threaded holes at the wire outlet of the junction box that match the waterproof joint. During installation, the threads on the inner side of the waterproof joint body are screwed into it using a wrench (or with bare hands). Since internal locking nuts are not required, the wrench position on the main body becomes the largest part of the axial section of the waterproof joint, which is also a decisive factor in the layout of the incoming and outgoing lines; Another method is to machine a slightly larger through hole on the thin-wall of the junction box based on the outer diameter of the inner thread of the waterproof joint. The waterproof joint passes through the through hole, and the inner wall of the junction box is fixed with an internal locking nut. Due to the fact that non-standard waterproof junction boxes have a wall thickness ranging from 2.5 to 3.5mm, the reliability of the connection cannot be guaranteed if threaded holes are made. Therefore, this type of product mainly installs waterproof joints by machining through holes. In this way, the diameter of the internal locking nut of the waterproof joint becomes a decisive factor in its layout on the junction box.
(2) Inner wall of junction box