What details should be paid attention to when installing waterproof bus ducts?

Detailed explanation of installation details of waterproof bus duct

1、 Detail control before installation

Material and seal inspection

Check whether the protection level of the busbar trunking (such as IP65/IP68) is consistent with the design requirements, with a focus on inspecting the sealing ring material (silicone rubber or EPDM rubber, with strong aging resistance and weather resistance), and ensuring that there are no bubbles, cracks or deformations on the surface.

Waterproof silicone sealant should be selected to ensure that there is no shrinkage or cracking after curing in a humid environment (if it meets the GB/T 14683 standard).

On site environmental pretreatment

If the installation path involves concrete walls, it is necessary to mark the installation position of the bracket with a level ruler in advance to avoid misalignment of the holes; If it is a steel structure, it is necessary to confirm that there are no burrs or welding slag at the welding points to prevent scratching the outer shell of the bus duct.

Measure the environmental humidity. When the humidity is greater than 85%, it is necessary to suspend outdoor installation or use a dehumidifier to reduce the air humidity to avoid moisture condensation affecting insulation.

2、 Key details of splicing and sealing

Interface Processing Specification

Before splicing, wipe the surface of the interface with anhydrous ethanol to remove impurities such as oil and dust, and ensure that the sealing ring is tightly attached to the groove.

The tightening of bolts should be done in 2-3 diagonal steps (such as the initial torque of 30N · m and the final torque of 50N · m for M12 bolts) to avoid uneven local stress and seal failure.

The outer sealant of the interface should be applied in a continuous and full circular arc shape (width ≥ 5mm, thickness ≥ 3mm), covering the bolt holes and gaps, and avoiding contact before curing.

Sealing details for wall/floor penetrations

The edge of the reserved hole needs to be chamfered (at a 45 ° angle) to prevent sharp edges from scratching the outer shell of the bus duct; The gap between the hole and the bus duct is filled with fireproof and waterproof mortar (ratio: cement: sand: waterproofing agent=1:2:0.05), and the outside is sealed with steel plate and coated with sealant.

A water stop ring (a steel plate ring with a thickness of ≥ 3mm) should be installed at the location where the floor slab passes through, fixed on the outer shell of the bus duct, and buried in the concrete of the floor slab to prevent water accumulation and leakage.

3、 Detail requirements for brackets and grounding

Installation accuracy of bracket

Horizontal support spacing ≤ 2m, vertical support spacing ≤ 1.5m, and at least one fixed support shall be installed on each floor slab; Rubber gaskets (thickness ≥ 2mm) should be placed at the contact area between the bracket and the bus duct to prevent metal friction from damaging the anti-corrosion layer.

After the installation of the bracket, calibrate it with a level ruler, with a verticality error of ≤ 1mm/m, to avoid uneven stress on the sealing components at the interface caused by the inclination of the bus duct.

Grounding system details

The grounding of the bus duct shell requires the use of copper braided tape (cross-sectional area ≥ 25mm ⊃2;), with both ends bolted together and coated with conductive paste to ensure a contact resistance of ≤ 0.1 Ω.

When connecting multiple bus ducts, the grounding terminals must be connected in series one by one and jumping connections are prohibited; The connection point between the grounding main line and the grounding grid needs to undergo anti-corrosion treatment (such as coating with asphalt paint).