1. Appearance of building wire

Smooth and round, uniform color, rubber insulation and copper conductor closely difficult to peel, bad quality rubber insulation looks thick, but after squeezing, the squeeze point will turn into white, it is easy for cable aging and fall off lead to electric leakage loss in the future.

2.Eccentricity ratio of building wire

Thickness of every rubber insulation circle is consistent, that is, whether the copper core in the middle of building wire, the eccentricity ratio is low.

3.Retardant of building wire

Burned rubber insulation with a lighter, the fire should be extinguished when lighter left the wire, and release of a small amount of white smoke, if the flames spread, release large amounts of white smoke indicates the rubber insulation is poor quality.

 
4. Copper core of building wire

High purity copper core is with features of anti-aging, high conductivity, and inferior copper core is with color yellow or white, with impurities. You can use a piece of paper rubbing on the copper core, if there is a black substance on the white paper, indicates impurities in the copper core .

5. Mark of building wire

You should notice whether the wire is with Certification of Quality, "CCC" sign, complete information on the rated voltage, length, date, manufacturer name and address etc.

 
6. Thickness of building wire

The size of poor quality copper core is smaller than regular factory, Good quality copper core insulation is thick, and  wire section diameter deviation should not be exceed 0.02%.

 
7. Length of building wire

Length of building wire should meet the national standard 100 ± 0.5m (That is take 100m as standard, permissible error 0.5 meters).

8. Weight of building wire

The whole plate building wire (100m), 1.5mm2 is not less than 1871 g, 2.5 square is not less than 2915 g, 4 square is not less than 4312 g, 6 mm2 is not less than 6107g.