Electrical safety · 电气安全
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| fuse/fjuːz/ | 保险丝 | bǎo xiǎn sī |
| live/laɪv/ | 火线 | huǒ xiàn |
| neutral/ˈnjuːtrəl/ | 零线 | líng xiàn |
| earth/ɜːθ/ | 地线 | dì xiàn |
| trip switch/trɪp swɪtʃ/ | 跳闸开关 | tiào zhá kāi guān |
| double insulation/ˈdʌbl ˌɪnsjuːˈleɪʃn/ | 双重绝缘 | shuāng chóng jué yuán |
Mains can be dangerous
- The mains supply runs our homes — but used wrongly it can give a shock or start a fire.
- A few simple safety features keep it under control.
- Let's meet the hazards, the three wires, and the fuse 保险丝.
市电能很危险
- 市电供应运行我们的家——但错误地使用它能给一个电击或引起一场火灾。
- 几个简单的安全特征让它处于控制之下。
- 让我们认识危险、三根线和保险丝。
Electrical safety route · 电气安全路径
Follow fault current and see how safety devices protect people. · 追踪故障电流，了解安全装置如何保护人员。
Hazards
- Damaged insulation — bare wires can give a shock or start a fire.
- Overheating cables — too much current makes a cable hot.
- Damp conditions — water lets current pass into a person.
- Overloading — too many appliances in one socket draw too much current.
危险
- 损坏的绝缘——裸露的导线能给一个电击或引起一场火灾。
- 过热的电缆——太多电流使一根电缆变热。
- 潮湿的条件——水让电流通入一个人。
- 过载——一个插座里太多电器抽取太多电流。
Select all · 所有 of these that are electrical hazards. · 选择所有属于电气危害的选项。
Bare wires, overloading and damp all raise the risk of shock or fire. Switching a lamp off is normal, safe use. · 裸露导线、过载和潮湿都会增加触电或火灾风险。关闭台灯是正常且安全的操作。
Live 火线, neutral 零线 and earth 地线
- A mains cable has three wires:
- the live wire carries the high voltage;
- the neutral wire completes the circuit at about zero voltage;
- the earth wire is a safety wire joined to the ground.
- The switch and fuse go in the live wire, so switching off cuts the appliance from the high voltage.
火线、零线和地线
- 一根市电电缆有三根线:
- 火线(live)携带高电压;
- 零线(neutral)在约零电压完成电路;
- 地线(earth)是一根连接到地面的安全线。
- 开关和保险丝在火线中,所以关掉就把电器从高电压切断。
Which wire carries the high voltage? · 哪根导线承载高电压？
The live wire carries the high voltage; the neutral is near 0 V and the earth is a safety wire. · 火线承载高电压；零线接近 0 V；地线是安全导线。
In which wire should the switch and fuse be fitted? · 开关和保险丝应安装在哪根导线上？
Putting the switch and fuse in the live wire means that, when off, the appliance is cut off from the high voltage and is safe. · 将开关和保险丝安装在火线上意味着，当设备关闭时，它会与高电压断开连接，从而确保安全性。
Fuses, trip switches 跳闸开关 and earthing
- A fuse is a thin wire that melts if the current gets too big, breaking the circuit before the cable overheats.
- Choose a fuse rating just above the normal current (e.g. a $13\ \text{A}$ fuse for an appliance using about $10\ \text{A}$).
- A trip switch (circuit breaker) does the same job but is faster and can be reset.
- A metal case is made safe by earthing (a fault sends a big current to earth and blows the fuse) or by double insulation 双重绝缘 (a plastic case that can never become live).
保险丝、跳闸开关和接地
- 一个保险丝是一根细线,如果电流变得太大就熔断,在电缆过热之前断开电路。
- 选一个刚好高于正常电流的保险丝额定值(例如对一个使用约 $10\ \text{A}$ 的电器用一个 $13\ \text{A}$ 的保险丝)。
- 一个跳闸开关(断路器)做同样的工作但更快且能被重置。
- 一个金属外壳通过接地(一个故障把一个大电流送到地并烧断保险丝)或通过双重绝缘(一个永不能带电的塑料外壳)而变得安全。
What does a fuse do? · 保险丝的作用是什么？
A fuse is a thin wire that melts if the current is too large, breaking the circuit before the cable can overheat. · 保险丝是一根细导线，如果电流过大就会熔断，在电缆过热之前切断电路。
An appliance normally draws about $10\ \text{A}$. Which fuse should it use? · 某电器正常运行电流约为 $10\ \text{A}$。它应该使用哪种保险丝？
Choose a rating just above the normal working current. A 3 A or 5 A fuse would blow during normal use; 13 A is the right choice. · 选择额定值略高于正常工作电流的保险丝。3 A 或 5 A 的保险丝会在正常使用中熔断；13 A 是正确的选择。
A double-insulated appliance with a plastic case needs an earth wire. · 具有塑料外壳的双绝缘电器需要接地线。
A plastic case can never become live, so a double-insulated appliance needs no earth wire (its fuse still protects the cable). · 塑料外壳永远不会带电，因此双绝缘电器不需要接地线（其保险丝仍能保护电缆）。
You've got it
- hazards: damaged insulation, overheating cables, damp, overloading
- three wires: live (high voltage), neutral (≈0 V), earth (safety)
- the switch and fuse go in the live wire
- a fuse melts if the current is too big; rating just above the normal current; double insulation needs no earth
你掌握了
- 危险:损坏的绝缘、过热的电缆、潮湿、过载
- 三根线:火线(高电压)、零线(≈0 V)、地线(安全)
- 开关和保险丝在火线中
- 一个保险丝在电流太大时熔断;额定值刚好高于正常电流;双重绝缘不需要地线