A must-read for owners of 40-year-old houses: Checklist of 8 signs of dangerous electrical wiring｜Self-rescue guide for fire risks

The electrical system of a 40-year-old house: a time bomb

In Taipei City, the average age of houses is more than 35 years old, and there are also a large number of old apartments in New Taipei that are more than 30 years old. These houses have witnessed the changes of the times, but the electrical systems inside the walls that were designed for "energy-saving light bulbs, fans, and televisions" are now overwhelmed by the modern life of "air conditioners, microwave ovens, dishwashers, and multiple computers." The insulation on wires is like a rubber band and will age and become brittle over time. The insulation performance and safety of wires that have been used for more than 20 years have declined significantly. This is not alarmist. According to past statistics from the fire protection unit, electrical fires are one of the main causes of residential fires, and old wiring is the core problem. As the owner of an old house, you have the responsibility to defuse this time bomb for your family.

Danger is right in front of you: Checklist of 8 signs of dangerous wires

You don’t need to tear down walls. You can find many warning signs through daily observation and feelings. Please check one by one whether the following conditions occur in your home:

Sign 1: No fuse switch (breaker) often trips for no reason
This is the clearest overload or short circuit alarm. If the switch on the same circuit (such as a living room socket) becomes prone to tripping without adding new electrical appliances, it means that the wires in the circuit may have aged, the load capacity has decreased, or there may be a slight short circuit somewhere in the circuit.

Sign 2: The socket or switch panel is "heated" or "discolored"
After using high-power-consuming appliances such as hair dryers and electric heaters, lightly touch the socket panel with the back of your hand. If it feels "warm" or even "hot", it means that the plug and socket are in poor contact, resulting in resistance and heat, which may melt the panel and cause a fire in the long term. If the panel has burnt or brownish discoloration, it is an extremely dangerous signal and should be stopped immediately.

Sign 3: The plug is "loose" and has "poor contact" after being inserted.
The plug cannot be inserted tightly into the socket, and the power will be cut off at the slightest touch. This is also a sign of poor contact and will produce arc sparks.

Sign 4: Lights often "flicker" or "dim for unknown reasons"
When high-power-consuming electrical appliances are turned on, if the lights in the whole room dim significantly simultaneously, it means that the voltage of your home circuit is unstable, and there may be a problem from the main switch box to the wiring. A flickering fixture in a single fixture may be a fixture problem, but multiple flickering fixtures may be a wiring problem.

Sign 5: Unidentified "burning plastic smell"
This is a strong warning that cannot be ignored! When the wire insulation melts due to overheating, it produces a unique smell of burnt plastic. If the smell persists, especially from the wall, ceiling or near the switch box, it is likely that the wires in the wall are smoldering. Please turn off the main switch of the circuit immediately and have it checked by a professional.

Sign 6: Still using "knife switches" with "fuses"
Open your home's main switch box. If you still see an old switch with a black blade on it and a fuse next to it, be sure to be alert. This kind of switch has poor protection performance, and the process of replacing the fuse itself carries the risk of electric shock. Modern standards should use "fuseless switches".

Sign 7: Extensive and long-term use of “extension cords”
If your home requires multiple extension cords extending from a single socket to meet your electricity needs, this in itself is proof of a serious lack of circuit planning. Plugging multiple high-power appliances into the same extension cord is a common cause of fires.

Sign 8: The outer covering of any "visible wires" is damaged or hardened
Check the wires of divine lamps, old desk lamp wires, or any old wires that are not hidden. Gently pinch it with your hands. If the outer skin is stiff, loses elasticity, or even cracks or holes appear, the copper wire inside may be exposed, which is extremely dangerous.

Self-rescue for fire risks: Four-step action guide after discovering signs

1. Stop immediately and isolate the danger: For sockets or switches that are hot, discolored, or have a burning smell, immediately turn off the fuseless switch of the circuit and stop using it. Before repair, tape the panel to remind family members not to use it.
2. Load reduction: Unplug unnecessary electrical appliances, especially those that have been on standby for a long time. Avoid using multiple high-power electrical appliances on the same circuit at the same time.
3. Seek professional diagnosis: Any of the above signs indicates the need for a comprehensive inspection by a professional electrician or plumber. They will use professional instruments to measure insulation resistance and check load and grounding conditions.
4. Comprehensive planning update: For a 40-year-old house, if there are many signs, partial repairs may only be postponed. Discuss the necessity and planning of "whole-room wire redrawing" with professionals. This is an investment, but in exchange for the safety and peace of mind of electricity use in the next 20 years.

Core Key Points for Electrical Updates in Old Houses

If you decide to update your electrical wiring, be sure to include the following key points:
• Replace all wiring: Use electrical wiring that meets the latest CNS standards (brands such as Pacific Wire and Cable).
• Update distribution box: Replace with a modern fuseless switch box with sufficient circuit number and safety margin.
• Plan independent circuits: Plan dedicated circuits for air conditioning, kitchen, and bathroom.
• Add safety devices: Install earth leakage circuit breaker (GFCI) sockets in bathrooms, kitchens and other places with heavy moisture.
• Ensure grounding system: Establish a complete and effective third hole grounding to prevent electric shock.

Safety is the only way home. Conducting electrical health inspections and updates for old houses is not a luxury renovation, but the most basic project to maintain the long-term and safe existence of this "home". Don’t let your beautiful old house be put in danger because of neglected electrical wiring.