Electrical appliances that are used in everyday life and at work, no matter what type of equipment they belong to, should clearly correspond to the list of tasks for which they are intended. The basic requirements for power tools, as a rule, are specified in the operating instructions that accompany this or that equipment. However, for all types of tools there are general requirements that require a detailed review for safe and high-quality work.
Power tools help to significantly speed up repairs, but they must be used properly.
Types and types of power tools
Tools according to their characteristics can be divided into professional and household. Professional power tools are distinguished by increased strength of the main components. Such tool is intended for long, intensive use.
As a rule, professional power tools meet the requirements of work in conditions of prolonged overload and increased wear. Professional power tools can be used around the clock, often in difficult environmental conditions, without much harm to the functional units of the device.
The household or nonprofessional electric tool differs from professional models only in the technical characteristics. It is much less wear resistant. Power tools should be spared and used with short breaks in work, often giving it a rest. The advantage in this case is the price of such equipment, choosing a tool from a reputable manufacturer, you can buy not only cheap, but also high-quality power tools that will serve you for a very long time.Back to table of contents
The general requirements that any power tool must meet are dictated primarily by the convenience of its operation.
Electrical circuit punch.
Requirement 1: Any powerful power tool must have a soft start function. This makes working with such a tool more secure, because the device does not twitch in your hand when you press the start button. The load on the network is significantly reduced due to a decrease in inrush currents.
Requirement 2: if the operation of a power tool, due to its functional features, leads to a large emission of dust or fine particles, the appliance should be equipped with a dust extraction unit or equipped with a special pipe to which the vacuum cleaner should be connected.
Requirement 3: the device is equipped with a reverse function - the shaft of the power tool must rotate in both directions. A great advantage is the availability of the function of smooth adjustment of the number of revolutions.
Requirement 4: The device must be protected against unacceptable mechanical stress. The torque limiting clutch will work if the drill or drill is jammed, and thereby protects the power tool reducer from damage.Back to table of contents
Power Tool Classification
Vibration damping perforator.
Before you start working with a power tool, you should understand what type it should be used. It is necessary to understand and in what class of the electric tool it is more expedient to apply for performance of this or that task.
- Class 1 - for tools of this class, all parts that are energized have double or especially reinforced insulation. The plug of the power tool of the 1 class is supplied with grounding contact.
- 2 class - the nodes of the energized tool are isolated. In special cases, some elements are double insulated.
- Class 3 - for power tools of this class, the nominal power cannot exceed 42 V. The internal or external circuits of such equipment cannot be under any other voltage. Power supply of this class of devices is provided by means of autonomous current sources. The mains supply can also be used with a converter or a power supply transformer with an open circuit voltage of not more than 50 V. The secondary circuit of the transformer should not be grounded.
Important stuff and requirements
Table of characteristics of screwdrivers.
Manufacturers of electrical equipment indicate the degree of protection of power tools on the body. Double square speaks of a two-level protection, where the first square is the insulation designation of all internal electrical components of the instrument, the second is the protection of all conductive housing elements that are accessible to the touch.
It must be remembered that the power tool, powered from the network, must be connected to a current source with a fixed cable of sufficient length and flexibility for comfortable work.
In case of damage to the insulation of internal components under voltage, grade 1 instruments should be provided with grounding of the parts accessible for contact. Electrical equipment class 2 and 3 is usually not grounded.
Power tools of classes 1 and 2 are designed for a voltage not exceeding 220 V, in the case of equipment designed to be powered from a DC network, and 380 V for appliances powered by alternating current.Back to table of contents
Features of safety requirements for power tools
Connection and rules of performance of work with power tools.
Before you start working with power tools of any class, you should check:
- complete set and reliable fastening of all parts of the device;
- the good condition of the power cable and plug, insulating parts, covers, handles and housing elements must be intact, without cracks or other physical damage;
- good condition of the switch, it should gently change the position; if the switch sparks, sticks, changes its position only under strong pressure, the device should be replaced and immediately shown to a specialist for the purpose of repair;
- work at idle.
A flexible non-removable power cable for a class 1 power tool must be provided with a ground conductor, which is connected at one end to a grounding contact on the plug and a grounding clip inside the instrument case. The same applies to equipment designed for single-phase power supply. To connect a three-phase power tool requires the use of a four-core power cable.
Power tools must not be grounded using a neutral wire. In this case, manufacturers do not guarantee the correct operation of the equipment, as well as the safety of the personnel working with it. Power cables of electrical equipment of class 3 must be equipped with plug plugs having a design different from plugs connected to the network with a voltage of more than 42 V.
As for portable step-down transformers, isolation transformers, as well as converters, such devices should be equipped on the higher voltage side with a cable with a socket for connection to a 220 V or 380 V network. The power cable should not be longer than 2 m and its ends should be connected bolted or soldered with a transformer winding pin. The low voltage side is equipped with sockets for the plug that is used for this class of power tool.