The Four Most Difficult Indicators of Cable Quality Control

According to reports, at present, there are several prominent problems in the production, operation and supervision of wire and cable.

Low Bidding for Construction Projects

The phenomenon that the construction project bidding is lower than the reasonable cost price is common.

Ineffective Implementation of the Main Responsibility of Enterprises

Some suppliers produce and supply products that have problems such as cutting corners, counterfeiting, failing to qualify for unqualified, and failing to meet the standards for safeguarding human health and personal and property safety.

Inadequate Construction Material Inspection System

In the key projects, the building materials products will be sent to the supervision unit and the supplier for inspection, and the sampling department of the supervision department is lacking.

Departmental Regulation does not Fully form a Synergy

Wire and cable products are used from production and circulation to construction sites. 

Different departments are responsible for supervision, supervision power is dispersed, information exchange is not timely, and the coordination mechanism is still not perfect.

In terms of quality control, the main unqualified items of wire and cable include 20 °C DC resistance, insulation eccentricity, smoke density, and bundle burning test.

Insulation eccentricity is an important indicator for medium and high voltage power cables. 

When the insulation thickness of power cables is uneven and eccentric, the electric field distribution inside the insulation layer is no longer uniform, and the deteriorated electric field will be concentrated at the thinner insulation. 

The thinner the insulation, the greater the electric field strength, which affects the mechanical stress resistance, chemical resistance and electrical performance of the cable. In severe cases, insulation breakdown can occur.

In addition, if the smoke density of the cable is unqualified, once the cable is misfired.

The corrosive nature of the acid gas in the smoke will cause corrosion to the surrounding electrical equipment, resulting in serious "secondary hazard", causing huge losses and very serious accidents.

In the major engineering, the wire and cable are in a relatively closed space. 

The two items of flame retardant and smoke density are unqualified. 

If the cable burns, it will consume oxygen sharply, and the generated smoke will also cause people to lose their way of escape. 

This is also a disaster.