What are the general reasons for cable aging? The direct cause of the aging failure of the wire and cable is the breakdown of the insulation due to degradation. There are many factors that lead to a decrease in conductivity and insulation.

According to actual operating experience, it can be summed up as the following situations:

1) Reasons for cable aging: external force damage. Judging from the operation analysis in recent years, especially in the high-speed economic development of Haipudong, a considerable number of cable failures are now caused by mechanical damage. For example, non-standard construction during cable laying and installation can easily cause mechanical damage; civil construction on directly buried cables can also easily damage cables in operation. l Sometimes if the damage is not serious, it will take months or even years to cause the damaged part to be completely broken down and form a fault. Sometimes a short-circuit fault may occur if the damage is serious, which directly affects the safe production of the electric power unit and the power user.

2) Reasons for cable aging: insulation is damp. This situation is also very common, and generally occurs at the cable joints in direct burial or piping. For example: unqualified cable joints and joints made in humid weather conditions will cause the joints to enter water or water vapor. For a long time, water branches will be formed under the action of the electric field, which will gradually damage the insulation strength of the cable and cause failure.

3) Reasons for cable aging: chemical corrosion. The cable is directly buried in the area with acid and alkali, which will often cause the cable armor, lead skin or outer sheath to be corroded. The protective layer suffers from chemical corrosion or electrolytic corrosion for a long time, resulting in the failure of the protective layer and the reduction of insulation. The cable is faulty. Chemical: the unit’s cable corrosion situation is quite serious

4) Reasons for cable aging: long-term overload operation. Overload operation, due to the thermal effect of the current, the conductor will inevitably heat up when the load current passes through the cable. At the same time, the skin effect of the charge, the eddy current loss of the steel armor and the insulation loss will also generate additional heat, which will increase the temperature of the cable. During long-term overload operation, the excessively high temperature will accelerate the aging of the insulation, and even the insulation will be broken down. Especially in the hot summer, the temperature rise of the cable often leads to the first breakdown of the weak insulation of the cable, so in the summer, there are more cable faults.

5) Reasons for cable aging: cable connector failure. Cable joints are the weakest link in the cable line, and cable joint failures caused by direct faults (poor construction) by personnel often occur. In the process of making cable joints, if there are original nets such as insufficient joint crimping, insufficient heating, etc., the insulation of the cable head will be reduced, which may cause an accident.

6) Reasons for cable aging: environment and temperature. The external environment and heat source of the cable can also cause the cable to overheat, insulation breakdown, and even explosion and fire.

How to determine the aging of the wire

1. Whether the current is leaking or even short-circuited to catch fire;

2. Hardening and cracks appear in the insulation;

3. The contact resistance increases and the joint becomes hot.

The main reasons for cable aging are listed as follows:

1. Long-term overload operation. Overload operation, due to the thermal effect of the current, the conductor will inevitably heat up when the load current passes through the cable. At the same time, the skin effect of the charge, the eddy current loss of the steel armor and the insulation loss will also generate additional heat, which will increase the temperature of the cable.

2. Environment and temperature. The external environment and heat source of the cable can also cause the cable to overheat, insulation breakdown, and even explosion and fire.

3. External force damage. Judging from the operation analysis in recent years, a considerable number of cable failures are caused by mechanical damage.

4. The insulation is damp. Generally occurs at the cable joints in direct burial or piping. Over time, water branches are formed under the action of the electric field, which gradually damages the insulation strength of the cable and causes failure.

5. The cable connector is faulty. The cable joint is a weak link in the cable line, and the cable joint failure caused by the direct negligence of the personnel (poor construction) often occurs.

6. Chemical corrosion. The cable is directly buried in the area with acid and alkali, which will often cause the cable armor, lead skin or outer sheath to be corroded. The protective layer suffers from chemical corrosion or electrolytic corrosion for a long time, resulting in the failure of the protective layer and the reduction of insulation. The cable is faulty.

Will aging wires increase power consumption?

The aging of the wire will increase the power consumption. After the aging of the wire, if the outer insulation sheath is damaged, it will not only increase the wire consumption, increase the power consumption, but also cause circuit fire. Need to be replaced in time.

The aging of wires will be accelerated under normal high temperature. When the temperature is too high, it will ignite the outer insulation and cause fire. In real life, many people who do not understand the common sense of the circuit just use wire cutters to twist two wires randomly when connecting two wires. Three turns and not tightened, which results in a small contact surface between the two wires at the joint. According to the knowledge of physics, the smaller the cross-sectional area of the conductor, the greater the resistance, the heating value Q=I square Rt, the larger the resistance, the higher the heating value.