First of all, if this type of junction box need to be waterproof, then its raw material should have a waterproof effect. At present, the main waterproof materials are plastic, rubber,metal and others. It is obvious that metal is not very suitable to be made as junction box because metal is a conductor. Using it as a junction box’s raw material can easily lead to leakage accidents. And rubber material is hard to be molded and easy to be aging. So plastic material is better choice than the others.

In addition to the choice of the materials, the structure of the junction box also has a great impact on its waterproof level.A reasonable structure of the waterproof junction box can effectively prevent the water that caused by all kinds of situation.

Waterproof cable gland is usually used with the junction box, we divide the waterproof junction box as 1 in 1 out, 1 in 2 out, 1 in 3 out and etc based on the drilled hole in the junction box. And we consider the size of the hole based on below factor.

1. The cable gland is usually installed on the wall of the junction box, so the drilled hole should meet the external thread size of the cable gland.

2. Considering the connection and the drilled hole should be at least 1 in 1 out, and it refers at least 2 waterproof cable glands and two drilled hole in the wall, so the size and the position of the hole and the size of the cable gland must be clear.

3. In order to promise the waterproof level, the connection should be completed via the cable gland whether connect the terminal or other electrical components in the junction box.

And there are silicon seals on the junction box, it makes the box and cover sealed tightly, which improves the waterproof level of the box greatly.