Judgment method for wire insulation aging
Wire line aging refers to the aging of the wire insulation layer and loss of insulation function. The aging of the insulation layer will cause leakage. The aging of the skin will be related to the degree of heating of the wire, the use environment, and the electrical load.
Wire line aging refers to the aging of the wire insulation layer and loss of insulation function. The aging of the insulation layer will cause leakage. The aging of the skin will be related to the degree of heating of the wire, the use environment, and the electrical load. We can easily judge the aging of the insulated circuit through formulas.
Judgment formula

Follow the wire to check the appearance, see if it becomes dark and hard and cracks.
Bending the wire with both hands for insulation, the skin is stiff and cracked.
Accurate method to measure insulation, the megohm is not low.
In rainy days, the humidity value can be small, and the value can be half as small.
According to the load and age, the life can be estimated.
Environment and electric current conditions, generally used for 20 years.
The use of wires exceeds the limit of life, and the connectors and wires are old and dangerous.
Check and inspect once a year, and replace it if it is aging.
Mantra explanation
1. "Check the appearance along the wire, darkening and hard cracks are seen. Bending the wire with both hands for insulation, stiff and cracked skin." The formula refers to observing the insulation layer along the wire. If the color of the insulation layer is found to be tarnished, darkened, Harden, crack, and partly fall off. When the insulated wire is bent with both hands, the wire is stiff, even the insulation layer is cracked, the insulation layer falls off, etc., which shows that the wire has experienced different degrees of aging and severe aging.
2. "Accurate method to measure insulation, megohm is not lower than two points. The humidity value in rainy days can be small, and the value can be less than half." The formula refers to a more accurate judgment of the insulation status of the circuit, and the insulation resistance meter can be used to measure the insulation of the electrical circuit. . The insulation of different lines has different minimum allowable values. For example, the minimum insulation resistance of a 220-volt household circuit in use is 0.22 megohm; the value of wet and rainy weather should not be less than 0.1 megohm. If the measured insulation resistance value is less than the above value, it indicates that there is a problem with the insulation of the electrical circuit.
3. "According to the load and age, the life can be estimated. The environment and current conditions are generally used for 20 years." The formula refers to the length of the wire life, which depends on the quality of the wire and the environment in which the wire is installed. The wire is mainly insulated by the outer layer of sheath. After a long time, it will be corroded by corrosive gas, and the insulation performance will gradually decrease. It will gradually age and become hard, become brittle or fall off. At this time, it will not be insulated.
The insulating layer on the exterior of household wires is mostly made of plastic and rubber, and it will age and lose its insulating effect after a long time of use. Generally, household wires can be used for about 20 years under normal conditions.
4. "The use of wires exceeds the age limit, and the connectors and wires are dangerous. Check and inspect once a year, and change them if they are aging." The formula refers to the power lines used by many households more than 20 years ago or earlier when the houses were built. Laying, the insulation layer of the wire will gradually loosen and age after long-term use, which will cause slight leakage, and in severe cases, it will cause short-circuit and fire. In addition, the wires used in the old house design have a small load-carrying load, which is not compatible with the requirements of modern home electrification. Under overload conditions, the aging speed of the wire insulation layer will accelerate. If the heat released by the core makes the temperature of the insulation layer exceed 250 degrees Celsius The wire will catch fire, so the wire must be replaced early.
Regularly carry out line safety inspections. The wires and electrical equipment should be inspected thoroughly by professionals at least once a year, especially the circuits with long service life at the joints. If unsafe conditions such as wire aging, damage, poor insulation, etc. are found, they should be repaired and replaced in time. In order to ensure the safety of electricity.