What are the inspection standards for galvanized cable trays?

Key points of cable tray inspection standards: inspection procedures and methods, surface treatment, glossiness, salt spray resistance, manufacturing precision, etc.

1. Surface Treatment

The bridge surface should be electroplated and coated for protection according to the requirements of the working environment. The thickness and adhesion of various protective layers should comply with regulations.

(1) Spraying or painting.

Cable tray body ≥50am. Detection method: according to GB1764 magnetic thickness gauge.

(2) Hot-dip galvanized cable tray body thickness 1.5~3mm, average thickness 55mm, local thickness 45mm and 3mm, local thickness 70mm and 55mm.

Inspection standard: GB/T13912-92.

Detection method: detected with a magnetic thickness gauge.

(3) Electrogalvanized zinc and zinc alloy.

According to Appendix B test, it should not peel off.

(4) Electrogalvanized zinc or zinc-nickel alloy.

Note (93) Cable tray body 12am.

(5) Adhesion—the firmness of the coating's adhesion to the base material.

Hot-dip galvanizing should not peel off when tested according to Appendix B.

(6) Spraying or painting.

At least Grade 3 in GB1720, inspected with an adhesion tester.

2. Inspection Procedures and Methods

(1) Shape: Opposite sides should be parallel, sides should be perpendicular to the bottom edge, cross-section should be straight, without bending, twisting, cracks, burrs, or other defects.

(2) Visual inspection of the groove should check whether the cable insulation, bulging, and sharp corners of the wiring are smooth, flat, and undamaged.

(3) Appearance: The coating and painting surface of the cable tray should comply with regulations, inspection methods, and visual methods.

3. Glossiness of Galvanized Cable Trays

The surface glossiness after protective treatment should not be less than 60%.

Test method: According to GB 1743 "Method for Measuring Glossiness of Oil Film," directly display the value measured by the gloss meter.

4. Manufacturing Precision

(1) Width deviation of cable tray

Deviation is 4mm when width is greater than 400mm, and 3mm when width is less than or equal to 400mm.

Note: Take the positive deviation of the cover plate and the negative deviation of the groove bottom width.

(2) Length deviation of galvanized cable tray.

Deviation is 2mm when length is less than or equal to 2m, and 4mm when length is greater than 2mm.

(3) Flatness tolerance of cable tray surface.

Flatness tolerance for hot-dip galvanized protective treatment is not more than 8mm/m; for galvanized and painted protective treatment, flatness tolerance is not more than 4mm per meter; vertical height tolerance of the bracket in free state is 1/100 of upward warping; other dimensional tolerances should comply with GB1804-V (coarse grade in the standard).

5. The grounding spray bridge should have good grounding. When the cable tray is connected by connecting plates, the connection resistance between any non-painted point and the grounding terminal should not exceed 0.1 ohm.