It feels numb when you touch the computer main unit, or gets an electric shock when you touch the casing of the microwave oven?
In many walk-up apartments or old mansions in Taipei and New Taipei that are over 25 years old, when you walk into the room, you will find that all the sockets on the wall are "two-hole sockets" and there is no third round "Grounding hole" at all. When many people use metal-cased electrical appliances (such as desktop computers, microwave ovens, ovens, refrigerators or dehumidifiers), they often feel a tingling sensation in their fingers when they step on the floor with bare feet. They even leave the hanging green ground wire hanging in the air or locked on the cement wall when plugging in the three-to-two adapter. This phenomenon is precisely because the indoor circuit system lacks a real "third line of protection-the equipment grounding wire."
Why did the old houses in early Taiwan not have ground wires?
Before Taiwan significantly revised the "Indoor Wiring Installation Rules" in 1999, regulations did not mandate that all indoor socket circuits in general residences must be equipped with equipment grounding wires. In order to save costs on wires and man-hours, early builders usually had only one live wire (Line) and one neutral wire (Neutral) in the distribution box. Without a grounding wire, once the internal insulation of the electrical appliance ages and the wire is damaged and touches the metal casing, the leakage current cannot be conducted back to the earth through the low-impedance grounding wire, and the entire electrical appliance casing will carry a 110V electrical voltage. When the human body touches it, the human body becomes a conductive path, and the current flows directly through the heart and into the floor, posing a fatal risk of electric shock.
Common fatal "false grounding" myths and wrong practices
- Myth 1: Lock the grounding wire on aluminum doors and windows or iron windows: There is no reliable electrical connection between aluminum doors and windows and the earth. Once electricity leaks, the entire iron window will become electrified, endangering the safety of your family and neighbors.
- Myth 2: Lock the grounding wire to the screw hole of the cassette or the steel bar: The steel structure in the cement of old houses is usually discontinuous and may contain stray voltages. Not only does it have no grounding effect, but it may also flow into home appliances in the reverse direction during a lightning strike.
- Myth 3: Short the neutral wire (N-phase) inside the socket to the ground hole (GND): This is an extremely dangerous and illegal practice of "boring the neutral wire"! Once the neutral wire of the building's power supply is in poor contact or the live wire and neutral wire are reversely connected, all electrical appliance enclosures will instantly be directly charged with 110V fatal mains power!
Three compliant anti-leakage upgrade plans without knocking on the wall
Without any major decoration or knocking on the wall, homeowners can greatly improve electrical protection in the following three ways:
- Replace all distribution box branches with "leakage circuit breakers (ELCB / GFCI)":This is the safest and most economical remedy recognized by the International Electrotechnical Commission (IEC) and Taiwanese regulations. The traditional non-fuse switch (NFB) in the distribution box is directly upgraded and replaced with a "leakage circuit breaker" with three-in-one functions of overload, short circuit and leakage protection. According to regulations, residential buildings should use high-sensitivity high-speed models (rated sensitivity current 30mA, action time within 0.1 seconds). Even if there is no physical ground wire, as long as the human body gets an electric shock and a leakage current exceeds 30mA, the circuit breaker will instantly trip and cut off the power within 0.03~0.1 seconds, saving lives before ventricular fibrillation occurs.
- Install "GFCI Receptacle" directly in the wet area: Replace the washing machine socket next to the kitchen sink, bathroom basin or back balcony directly with a GFCI leakage-proof socket with its own leakage detection chip and test button. Once an imbalance in incoming and outgoing current is detected, the outlet itself cuts off power within 0.025 seconds.
- Re-pulling the dedicated grounding wire (drawing the wire and threading it through the pipe): If there is enough space inside the concealed pipe, you can ask a professional Class A plumber to use a threader to pull out the original two wires and re-thread the three wires "live wire, neutral wire, and green ground wire", and guide the green ground wire all the way back to the ground copper bar of the main distribution box to connect it to the building's main grounding system.
Which areas are “mandatory” to have leakage protection according to law?
According to current Taiwanese regulations, the following areas in a house are high risk environments for electric shock. Regardless of whether there is a ground wire or not, it is mandatory to install a leakage circuit breaker: all sockets in the bathroom, sockets in the kitchen within 1.8 meters from the edge of the sink, balconies and outdoor sockets, dedicated circuits for electric water heaters, and sockets for drinking fountains and toilet seats. Regularly pressing the "yellow/gray test button (TEST)" on the circuit breaker every six months to confirm that the switch can bounce off normally is the basic homework for protecting life safety at home.
The Ministry of Economic Affairs' latest "Regulations on Consumer Electrical Equipment Installation" and the key points of electricity safety in old houses
Due to the popularity of high-power household appliances (such as air fryers, microwave ovens, dishwashers, instantaneous electric water heaters, and IH furnaces) in recent years, the Energy Administration of the Ministry of Economic Affairs has revised the "Regulations on Consumer Electrical Equipment Installation" many times to strictly require the diversion and protection mechanisms of residential electricity circuits. Statistics show that more than 30% of building fires in Taiwan are caused by electrical factors, among which "old wire insulation deteriorates and short circuits", "socket contacts are oxidized and loose, poor contact" and "non-fuse switch (NFB) overloaded and failed to trip" are the three main fatal causes.
Old apartments in Shuangbei that are more than 30 years old have a total original designed power capacity of only 30A to 40A, and several rooms often share the same 1.6mm or 2.0mm circuit. In the modern standard safety configuration, kitchen electrical cabinets, bathroom equipment, and air-conditioning and heating machines must all be equipped with 5.5mm² dedicated circuits (single circuit and single socket). It is recommended that the main switch box be upgraded to a busbar (Busbar) integrated distribution board, and the total amperage is increased to 75A or 100A (a qualified electrical appliance contractor needs to be entrusted to Taipower to review the additional power capacity).
Residential electricity self-test and regular inspection checklist
- Appearance and temperature of the socket: Touch the outer cover of the commonly used socket lightly with the back of your hand. If it feels lukewarm or if you find that the plastic socket is yellowed and charred, or the plug is loose and shaking after being plugged in, it means that the internal copper plate clamping force is exhausted or the contact resistance is too high, and you should immediately cut off the power and replace it.
- Regular testing of leakage circuit breakers (ELCB): For leakage circuit breakers in humid places such as balconies, bathrooms, and kitchen sinks, regulations require that the "TEST button" on the switch be pressed once every 1 to 3 months to confirm that it can automatically trip and cut off the power supply instantly.
- Serial connection and overloading of extension cords are strictly prohibited:Extension cords should be purchased with CNS certification and 2.0mm thick wire diameter products with automatic overload power-off protection. High-energy-consuming appliances should not share the same extension cord to ensure zero hidden dangers to life and property at home.
