When a power cable carries a certain load current, it will inevitably heat up. As the load current increases, the cable surface temperature increases. If not addressed promptly, the consequences can be unpredictable. A cable surface temperature below 60°C is generally safe. From a power supply maintenance perspective, the lower the temperature, the better. So, what causes cable heating during operation? What harm can it cause?
Why do cables heat up during operation?
1. The cable conductor resistance does not meet requirements, causing the cable to heat up during operation.
2. Improper cable selection results in a cable with a conductor cross-section that is too small, causing overload during operation. After prolonged use, the cable heats up due to imbalanced heat generation and heat dissipation.
3. Cables are installed too densely, resulting in poor ventilation and heat dissipation. According to Jinhuanyu Wire and Cable's editor, this can also cause cables to heat up during operation.
4. Poor connector manufacturing techniques and loose crimping can lead to excessive contact resistance at the connector, which can also cause cable heating.
5. Poor insulation between cable phases results in low insulation resistance, which can also cause heating during operation.
6. Damage to the armored cable sheath can cause water to enter the cable, slowly damaging the insulation and gradually reducing the insulation resistance, which can also cause the cable to heat up during operation.
What are the solutions for cable overheating?
If the cause of cable overheating is not identified and promptly corrected, continued operation will result in insulation thermal breakdown. This can cause a phase-to-phase short circuit, which can even cause a fire. A heating water heater power plug is usually caused by a poor fit with the socket. However, normal heating should be considered. A plug surface temperature less than the ambient temperature plus 50°C is considered normal. Abnormal heating suggests replacing the socket or inspecting the plug-to-socket fit.
1. Poor contact between the plug and socket, combined with a high power load, can cause the plug to heat up. Examples include electric kettles and electric irons.
2. Loose wires in a new plug can be caused by poor manufacturing processes.
3. Long-term use of old plugs can degrade the insulation (or the plug may become loose).
How can we safely use plug cords?
Plug cords heat up primarily because prolonged use of electrical equipment increases the load on the cords. Especially for multi-purpose outlets, if several high-powered devices are connected simultaneously, the power cords will inevitably be overloaded, and in such situations, the cords can easily burn out. Therefore, we should pay attention to the proper distribution of electricity and regularly inspect plug cords and outlets to check for signs of wear and tear and poor contact between the plug and outlet.
Sometimes, due to poor manufacturing processes, the plug's wire ends may not be secure, resulting in poor contact and causing the plug to heat up.
The above explains the causes and solutions for cable heating. We remind every household to be aware that plugs age with prolonged use, and their insulation degrades, so they should be replaced promptly. For plug cords used with high-powered appliances, we recommend using ones with enlarged cores and, ideally, grounding prongs. If you find that the power socket or electrical plug is very hot and causes the electrical appliances to burn out, do not act rashly and handle it with care.
