What is the problem of three phase four wire electric energy meter connection?

In fact, what you said is right, but we usually install a metering box between the meter and the transformer, so that the current transformer S1 and S2 of phase A are connected to the foot of the metering box and S2 is grounded, and then connected to the watt-hour meter from the metering box. When the watt-hour meter needs to be re-calibrated or replaced, then a short connector between the feet of the metering box is connected, then phase A is connected by the short connector, by S1, by the current transformer, by S2 to the ground, so that the secondary circuit of the transformer will not open the circuit and produce high voltage.

The watt-hour meter with a short tab is not connected to the power supply terminal, and its power supply terminal is connected in parallel with the 1 pin (short tab). If the wiring is described, the short tab connected to the 1 pin should be removed and connected to the power supply. It can also be dismantled, phase A and transformer S1 are connected to 1 pin at the same time, and the grounding can be canceled.

As you say, phase A is connected with a current; B-phase current connection; C-phase current connection; Three-phase current transformer S2 series grounding respectively connected to three-phase voltage A, B, C; 10 connected to the neutral line. Some tables have 11 binding posts (in fact, 10 and 11 are connected in series internally). The specific situation should be opened to see the wiring diagram.

There are two types of connections: star and triangle.

Fill in the questions, such as how many transformers there are.

The three-phase four-wire meter is one of the most common meters, containing three live wires, one neutral wire, and three phases. So what is the common connection method of three-phase four-wire meter, and what should be paid attention to in indoor switch wiring, do you understand? Now let's take a look.

1. What is the common connection method of three-phase four-wire meter?

1. On the three live lines, mark U, V, and W respectively, and the other line is marked as the zero line; 2. Mark the three phases as A, B, and C respectively; 3. Connect the live wire U, V, and W to the incoming position of A, B, and C phases respectively; 4. The outgoing line of A, B and C phases needs to be connected to the load; 5. Connect the neutral line behind the wire.

2. What should be paid attention to in the wiring of indoor switches.

1. Switches and sockets need to be installed in each space of the indoor car stall, and the switches in each area are a little different. For example, in the bathroom, the moisture is relatively large, in order to be safe, not only to buy a socket with switches and indicators, but also to have a waterproof cover on the outer surface of the socket to avoid water vapor entering the socket and causing a short circuit.

2. The location of the interior design should be determined according to the use habits of the family. If the people in the house are more accustomed to using their right hand, then the switch is suitable for installation on the left side of the front side of the door. In addition, if it is installed at the head of the bed or in the living room with a large space, it is necessary to choose a dual-control switch to make daily use more convenient.

3. The height of the switch and socket installed on the TV wall also needs to be designed. If the wall is higher, the height of the switch and socket needs to be raised appropriately, and if the wall is lower. And install a 5-hole socket indoors as much as possible, close it and make the socket and the TV outlet socket more than different.

What is the common connection method of three-phase four-wire meter, and what should be paid attention to in the wiring of indoor switches, I will introduce it here, do you understand? The wiring of the three-phase four-wire meter is not difficult, and the wires only need to be connected in the correct way to ensure normal use.

If the load current exceeds the range of the watt-hour meter, a current transformer must be used to reduce the current. There is a terminal connection diagram on the inside of the wiring groove cover of the three-phase four-wire watt-hour meter, which should refer to the wiring. Each binding post has more than one fastening screw, and the wire head should be fully secured under them when wiring.

Safety precautions for using a three-phase watt-hour meter:

1. The three-phase watt-hour meter can be installed and used after passing the inspection before leaving the factory and sealing the lead seal. If it is found to be a lead-free or expired energy meter, you should ask the relevant department to re-calibrate it before installing and using it to ensure accurate metering.

3. The watt-hour meter is installed indoors, choose a dry and ventilated place, and the bottom plate of the watt-hour meter should be placed on a solid fire-resistant wall that is not easy to be shaken by moisture.

4. When the watt-hour meter is installed, the installation stipulates the phase sequence (positive sequence) and the correct wiring diagram for wiring. The wires in the junction box should be fixed tightly to avoid poor contact of the connector and burning the junction box.

The three-phase four-wire wiring method is as follows:

When the three-phase alternator supplies power to the outside, the ends of the three groups of coils X, Y, and Z are connected together, and a line is drawn from the connection point, which is called the neutral line, also called the neutral wire. Then draw a wire from the other end of the coil winding, A, B, and C. In this way, a three-phase four-wire system (three live wires and one neutral wire) is formed, and this connection method is called the star connection method.

Because the three-phase four-wire power supply can supply two different voltages of 22V and 38V at the same time, it is widely used. The star connection is represented by y, which is also called the y connection. If the middle line is not drawn, the power supply to the outside with three wires is called a three-phase three-wire system.

You belong to the electric energy meter directly connected in series in a primary circuit, although the connection method is correct, but the field rarely uses this direct series connection method.

Because the rated current of the meter is very small, the actual load current may be greater than the rated current of the meter, and when the load current is greater than the rated current of the meter, the metering of the energy meter will be inaccurate.

Therefore, a current transformer is generally installed on the site, and the electric energy meter is connected to the secondary side of the current transformer, and the reading needs to be multiplied by the conversion ratio of the current transformer to obtain the actual electricity consumption.

Below is an example of a wiring diagram with a current transformer.

Usually, the power supply incoming line should be directly connected to the metering meter, and the outgoing line of the meter should be connected to the pile head of the air switch.

Wrong. The installation specification requires that the power cord should be advanced to the meter, and the rear entry and air opening.

After looking at the incoming and outgoing lines of the live line of the meter, the zero line, there should be no wrong connection.

In addition, I personally feel that it is better to install the meter at the lower end of the switch, and the circuit breaker switch can play a protective role at the same time, and it is also convenient for maintenance.

Flip over the terminal cover, and you can see the wiring diagram of the three-phase four-wire meter. Wherein connect the S1 end of the secondary side of the current transformer, that is, the current inlet terminal is connected to the S2 end of the secondary side of the current transformer, that is, the current outlet end is connected to the three-phase power supply respectively, and the zero end is connected. For safety, the S2 end of the current transformer should be connected to ground after being connected.

It should be noted that the current measurement sampling of each current transformer must be in phase with its voltage sampling, i.e. as a group for a group and as a group.

Three-phase four-wire meter wiring: Look!