In the third and fourth quarters of 2024, the Guangzhou Municipal Administration for Market Supervision conducted a supervision and random inspection of the quality of wire and cable products, and a total of 62 batches of samples were spot-checked, and after inspection, 2 batches were found to be unqualified.

This spot check is based on GB/T 12706.1-2020 "Rated voltage 1kV (Um=l.2kV) to 35kV (Um=40.5kV extruded insulated power cables and accessories Part 1: Rated voltage 1kV (Um=l.2kV) and 3kV (Um=3.6kV) cables", GB/T 9330-2020 "Plastic Insulated Control Cable", GB/T 5023.3-2008 "Rated voltage 450/ PVC insulated cables with a rated voltage of 450V and below – Part 3: Unsheathed cables for fixed wiring, GB/T 5023.5-2008 PVC insulated cables with rated voltage of 450/750V and below – Part 5: Flexible cables (flexible wires), JB/T 8734.2-2016 "PVC insulated cables and flexible wires with rated voltage of 450/750V and below – Part 2: Cables and wires for fixed wiring" and other standards, the following items are inspected:

Power cable products: average thickness of insulation, thickness of the thinnest part of insulation, thickness of the thinnest part of non-metallic sheath, conductor resistance, insulation resistance constant at the maximum temperature of the conductor, 4h voltage test, tensile strength before insulation aging, tensile strength after insulation aging, elongation at break before insulation aging, elongation at break after insulation aging, tensile strength change rate before and after insulation aging, elongation at break change rate before and after insulation aging, PVC insulation thermal shock, EPR, HEPR and XLPE insulation thermal extension, Shrinkage of XLPE insulation, tensile strength of non-metallic sheath before aging, tensile strength of non-metallic sheath after aging, elongation at break of non-metallic sheath before aging, tensile strength change rate of non-metallic sheath before and after aging, elongation at break of non-metallic sheath after aging, change rate of elongation at break of non-metallic sheath before and after aging, weight loss of ST2 type PVC sheath, thermal shock of PVC sheath, flame retardant of a single cable of cable;

Plastic insulated control cable products: conductor resistance (20 °C), finished product voltage test, insulated core voltage test, insulation resistance, conductor structure size inspection, insulation thickness of the thinnest point thickness, sheath thickness of the thinnest point thickness, outer diameter, tensile strength before insulation aging, elongation at break before insulation aging, maximum change rate of tensile strength after insulation aging, maximum change rate of elongation at break after insulation aging, thermal loss of insulation, thermal shock test of insulation, insulation high temperature pressure test, insulation low temperature bending test, insulation low temperature impact test , sheath tensile strength before aging, sheath elongation at break before aging, maximum change rate of tensile strength after sheath aging, maximum change rate of elongation at break after sheath aging, thermal weight loss of sheath, thermal shock test of sheath, high temperature pressure test of sheath, low temperature bending test of sheath, low temperature tensile test of sheath, low temperature impact test of sheath, single combustion test of finished cable, mark, thermal extension test of insulation;

PVC insulated cable and wire products: conductor resistance, finished cable voltage test, absolute