On March 20, a mother and son died of electric shock in a rental house in Shenzhen due to suspected leakage of water heater while bathing; on February 22, a female tenant died of electric shock in a rental house in Taihe Town, Baiyun District, Guangzhou city due to suspected leakage of electric water heater, and another woman in the same house was also electrocuted when she tried to rescue Identification record
Location: Guangdong Huabiao product quality and Safety Research Institute
Tools: pressure tester, microcomputer constant temperature and humidity tester, water heater simulation setting, etc.
First of all, the electric water heater is simply divided into water storage electric water heater and fast heating electric water heater.
Water storage electric water heater: to heat water and store it in a container. Equipped with a water temperature control device, when the set temperature is reached, the temperature controller will disconnect the heating pipe current and enter the insulation state. Before use, it needs to be heated in advance, and the power switch can be turned off before showering.
Fast heating electric water heater: also known as instant electric water heater. According to engineers, the advantages of fast heating water heater are convenient installation and small size. But it must be used at the same time of boiling water, so the leakage risk is relatively high.
Leakage of kitchen hot water bottle
Shower in the bathroom may also cause electric shock
Experiment process: engineers use non leakage stainless steel soup pot to simulate a normal water heater, then connect it with a leakage electric kettle and insert it into a parallel socket. The internal grounding of these sockets is connected, but the grounding of the main power supply is not connected to the real ground.
With a 220 volt bulb, one end of the two wires is connected to the zero line of the power socket, and the other end is connected to the metal shell of the electric kettle and the water heater respectively. Turn the main switch, the brightness of the bulb reaches the maximum. "This means that both appliances are in leakage state. "Touch the shell of the soup pot with the measuring pen, and the indicator light of the measuring pen will be on. The voltmeter shows that the pot voltage has reached 220 volts.
When the main power supply is not connected to the real earth, as long as one of the grounded electrical appliances in the house is electrified, other grounded electrical appliances will be electrified in the shell, and electric shock may occur at any time when people touch the electrified metal. "In this case, if you are bathing with an electric water heater, holding the nozzle in your hand is equivalent to holding a high-voltage wire. '
Experimental results: when the main power supply is not connected to the real ground, the leakage of the hot water pot in the kitchen may also cause electric shock to the person who is taking a shower in the bathroom! Many household appliances and electrical equipment have metal shells, once the electric leakage such as short circuit occurs, it is easy to cause electric shock to the user.
Magnesium bar is not replaced in time
Bath water can be charged
Experiment process: hang a live wire (electrode) on the cup, 'the cup is like the inner container of an electric water heater'. There is running water in the cup, which is equivalent to an electric water heater storing water. Put the measuring device in the water and the light bulb is on again. The voltmeter measured that the highest voltage in water is 180V, and the closer to the electrode, the higher the voltage.
Experimental results: This shows that when the internal heating element of the electric water heater leaks electricity, the water will conduct electricity. The water outlet of the electric water heater, the metal parts of the shower and the faucet all become live parts. If there is no reliable grounding protection measures, the current will be directly led into the human body and an electric shock accident will occur immediately.