Electrical safety rules: what you need to know and how to apply them in practice

There are a huge number of normative documents and regulations that govern the basic rules of electrical safety. This topic is very comprehensive and covers all types of electrical work and the operation of power tools. You can get acquainted with it thanks to a short, but understandable presentation of the basics of electrical safety when carrying out work that is associated with electricity in everyday life.

Theoretical basis

It is impossible to imagine a single household without a power supply system. The household consumer is supplied with electricity with a voltage of 220 V (less often 380 V), with a frequency of 50 Hz. The current strength is usually limited by circuit breakers, a level of 16 A (less often 25), which corresponds to a power of 3.5 kW (5.5 kW).

Such characteristics of electricity are considered very dangerous for human life and health. An electric shock for one can be a mild shock, and for another it can be fatal, and all this is due to the internal resistance of a person. It is not constant and can fluctuate within significant limits.

instagram viewer

The conditional resistance of the human body is approximately 1 kOhm. Humidity or alcohol in the blood can reduce it by several times. Even for an indicator of 1 kOhm, a current of 1 A is dangerous. The duration of the effect of the current on the body also plays a role: the longer it is, the more critical it is.

The main danger comes from the physiological effects of electric current on the heart and brain. In production where a current with a high voltage and current strength is used, a person can literally burn out.

The degree of threat of electric shock also depends on the "path" along which it flows through the human body. This "path" is called a "current loop". The most dangerous of them are those that pass through the whole body (arm - arm, arm - leg, head - legs) - in this case, the heart will be hit in any case.

The danger increases when a short circuit through the human body passes between phase and zero, or in the case of contact with the phase, if a person, for example, holds on to the radiator, stands with bare feet on damp ground etc. Be that as it may, there are many tragic cases behind non-compliance with electrical safety rules.

Basic safety rules

Even children should know the basic rules of electrical safety, especially since it is all easy to learn:

1. It is unacceptable to use metal or wire jumpers instead of burnt out fuses (they are also called "bugs" among the people).
2. It is forbidden to use electrical wiring with damaged or missing insulation.
3. It is necessary to monitor the health and integrity of sockets, switches, cartridges and other integral elements of the power supply system.
4. All work on repair, installation, modernization of the power supply system should be carried out with the voltage disconnected. It is even better if they are produced by professionals. But you should also take measures to prevent accidental resumption of power supply by third parties during the work.
5. In rooms with increased humidity (for example, a bathroom, a basement, a cellar), it is undesirable to use a voltage of 220 V.
6. Do not use defective power tools.
7. When working with electrical appliances, do not touch metal water pipes, batteries and other elements that are in stable contact with the "ground". It is advisable to work with dielectric shoes and gloves.
8. Do not work with ungrounded electrical appliances if they are provided by the manufacturer.
9. Drilling of building elements and structures, cutting of grooves can be performed only after making sure that there are no electrical wiring and current-carrying elements under the cutting site.
10. Before applying voltage to the repaired device, you should check it with a tester for at least a short circuit.
11. It is advisable to work with power tools with a partner so that in the event of a dangerous situation he can come to the rescue.

Classification of power tools

The degree of electrical shock hazard depends on the class of the power tool. It is customary to distinguish 5 classes:

• Zero class. It has absolutely no protection against electric shock to the human body. Typically, such devices are enclosed in other device housings, which, in turn, are grounded. During operation of such devices, it is forbidden to be near them. In case of emergency, you can approach only by equipping yourself in dialectical clothing.
• First grade. Electrical appliances have insulation and grounding elements, but they are connected to the mains without a grounding conductor. Grounding or neutralization is connected separately, usually to the device case.
• Second class electrical appliances are distinguished by the presence of a structural plug, which is necessarily equipped with an earthing contact. Typically, such devices are connected to a three-wire network (phase-zero-ground).
• The third class of devices does not have grounding contacts on the plug and the possibility of a separate ground connection, but they are equipped with reinforced insulation.
• Class four devices are the safest. They are powered up to 42 V, which minimizes the possibility of electric shock.

Compliance with safety rules when working with electrical devices, as well as common sense, help to avoid electrical injuries and, as a result, preserve health and life.