To account for the electricity consumed in the garage, a meter is needed. The safety of its operation depends on correctly selected electrical equipment. In this article, we will help you understand the nuances of choosing electric meters for non-residential premises.
Before you buy an electric meter in a garage, you should understand a little about the features of the devices in question. This requires:
- Calculate the maximum current consumption. If you are not planning to install energy-intensive equipment, then a device with a capacity of 10-50A will be enough for you. Otherwise, the appliance must withstand a load of 100A.
- Find out the total number of phases. For example, the installation of metal-cutting units involves a three-phase power supply.
- Observe the accuracy class of the device. Usually it is 1.5-2%. Otherwise, the measuring equipment will not be accepted into operation by the regulatory authorities.
- Decide on the characteristics of the device. Its price depends on additional functions.
- Focus on installation requirements. Not all meters can be mounted on a DIN rail.
- Check the availability of a passport, warranty and seals. They should be intact.
IMPORTANT: Before installing electrical equipment with maximum power, you need to know the parameters of the supply network. This information can be clarified in the services serving GSK
Types of counters
To account for consumed electricity in non-residential premises, the following types of power plants are mainly used:
- Induction (electromechanical). Relatively inexpensive. They can work at low temperatures. Of the shortcomings, they may have an error in measurements.
- Electronic. They allow you to control the consumed electricity with the smallest errors. Not all device models can operate at low temperatures.
IMPORTANT: Modern electronic meters support work with communication modules, which allows you to take readings remotely
Three-phase meter for garage
In the garage, in which welding machines and machines are often used, it would be logical to purchase a three-phase meter.
As a rule, such options are used in conditions where the rated power is more than 15 kW. They have many functions, they are widely used in the household network and in the control of three-phase electric motors.
The difference between such a device from a single-phase one is that it is capable of functioning under conditions of consumption of a large amount of energy.
There are several types of three-phase meters:
Single rate. It is considered standard, it has only one tariff, it cannot be selected. Suitable for installation in garages and industrial facilities.
Two-tariff (multi-tariff). At night, the price for 1 kW of energy is significantly lower. This is beneficial for those who carry out activities in the garage at night, which significantly reduces the cost of electricity.
Three-phase meters are of two types:
- Electronic. The devices have a modern digital display.
- Mechanical. Includes a screen with an arrow that shows the number of consumed kW.
The efficiency of both devices is on the same level. Differences may be in appearance or additional options, for example, a remote control, but such models will cost significantly more.
Different types of meters differ structurally. The mechanical device consists of two coils: one is current, and the second is supplied with voltage. Inside them there is a metal disc fixed in plain bearings. A worm pair is mounted on its axis, which is connected to a mechanical counter. During operation of the device, an electromagnetic field arises, which makes the disk rotate, due to which the amount of electricity consumed is counted.
In electronic devices, there is no mechanical part at all. These devices convert analog signals into digital ones. For this, special pulse sensors are used, which are connected to electricity using a transformer. The signal goes to the microcontroller, which allows you to calculate the consumed electricity. This data is shown on a digital display. Such devices have a high class of accuracy and allow to accumulate and transmit information through special communication channels.
Three-phase meters have a similar design. The most popular devices are considered electronic. Some models support single phase accounting. They are reliable, integrated into automated accounting systems, and are small in size.
Connection method and accounting type
When choosing an electric meter, consumers pay attention not only to the principle of operation, but also to the method of connection, and to the type of metering of consumed energy. Three-phase devices are connected directly or indirectly.
The installation scheme is quite simple:
- When a small amount of energy is consumed, the device is installed directly in the break of the supply wires.
- In the case of using powerful consumers, indirect connection is used with the operation of intermediate transformers.
The metering type of the device plays an important role in saving financial resources if three-phase meters are used. During the operation of such a device, active and reactive energy is consumed. If financial accounting is carried out by a single-phase electrical appliance, the active part is calculated. And when a multiphase unit is operating, electricity is consumed first, after which it returns through the network. With energy metering, you can save money.
Preparatory stage before installation
When the device has already been purchased, the question arises about its installation. Before connecting, you need to undergo appropriate training. And follow the algorithm of actions:
- Box installation. It includes two parts, the first is the inner part, in which there are two slats and a zero bus, and the second is an outer element in the form of a protective cover with a door. Mounts to the wall at a height of approximately 0.8-1.7 meters from the ground. The box must be securely fixed.
- Installation of modular elements. To increase the level of safety, a special circuit breaker is installed in front of the device. This will prevent fire or short circuit under heavy load. The next stage is the installation of outlets, a step-down transformer, to which portable lighting is connected for work in the basement or pit.
- Meter connection. Usually the manufacturer indicates the connection diagram on the back cover of the device. The phase wire is connected to terminal 1, and the zero wire to terminal 3.
- Attaching contacts. Each contact must be carefully mounted, since after installing the seals, there will be no access to them.
- Automatic switches. You need to connect the supply wires through the upper row of contacts, and the outgoing ones through the lower one.
- We connect the device and protective equipment. The load is connected to terminal 2 (phase) and terminal 3 (zero). Be sure to check the reliability of the fixed contacts.
IMPORTANT: Before carrying out installation work, make sure that the electricity is turned off. To do this, use the voltage indicator. If you are not confident in your abilities and there is no understanding of the topic and features of working with the power grid, be sure to contact a specialist
It is relatively easy to install the meter. Be sure to adhere to safety precautions and carefully check the circuit and connections. If the wires are not properly secured, they can start to spark. But if the owner does not have experience in installation work, and he doubts his abilities, in this case it is worth contacting a specialist.
PUE allows self-assembly of the board with the installation of a meter. In this case, a mandatory requirement is to call a specialist who will check the connection diagram and seal the device
Of the shortcomings
Some models of electricity meters may have their own drawbacks. These include:
- Do not match blinking with clicks, which will mislead the user.
- Telemetry problems.
- Poor build quality.
- Display without backlight.
- Short term for verification.
- Poor performance at low temperatures.
- High price.
- Lack of moisture protection.
Yes, for some, minor nuances do not matter much, but still, it is better to study the subject from all sides.
Which counter to choose
And finally, a list of recommendations:
- If you often use energy-consuming equipment, you should consider installing a multi-tariff device.
- When choosing a meter, you should pay attention to the type of fixing in the switchboard.
- Consider the accuracy class of the instrument.
- If you want to take readings remotely, buy devices that support work with communication modules.
- Check the presence of a technical passport and accompanying documentation in the kit, incl. instructions.
The correct choice of an electric meter is a matter of safety during its operation and maintenance, as well as saving money on electricity bills.