Analysis of Future Energy Development Prospects: Smart Meters as the Next Breakthrough Point

1. The connection method of single-phase electricity meter

      1. Direct access method If the power of the load is within the range allowed by the power meter, that is, the current flowing through the current coil of the meter will not cause the coil to burn out, then the direct access method can be adopted. Direct access method: single-phase power meter has a total of four terminal blocks, from left to right according to 1, 2, 3, 4 numbers, there are generally two types of wiring, generally 1, 3 connection wire, 2 and 4 connection wire; the other is to connect the line to 1 and 2, and to connect the line to 3 and 4. Regardless of the connection method, the phase wire (live wire) must be connected to the terminal of the current coil of the meter. Due to the special wiring of some meters, the specific wiring method needs to refer to the wiring diagram on the terminal block cover.                         
      2. When measuring the power consumption of a single-phase circuit with a large current with a single-phase power meter, the current transformer should be used for current conversion, and the current transformer should be connected to the current coil of the power meter.
      There are two ways to connect: 

      (1) The connection method when the 5th and 1st ends of the single-phase power meter are not disconnected. Since the short splice in the meter is not disconnected, the K2 terminal of the transformer is not grounded. (2) The connection method when the short splice at the 5th and 1st ends of the single-phase power meter has been disconnected. Since the short tab in the meter is disconnected, the K2 terminal of the transformer should be grounded. At the same time, the voltage coil should be connected to both ends of the power supply.  

2. How to connect a three-phase four-wire meter 

      1. Direct access method If the power of the load is within the range allowed by the power meter, then the direct access method can be used. 
      2. Through the transformer access method When using a power meter to measure the electricity consumption of a high-current three-phase circuit, because the current flowing through the line is very large, such as 300-500A, it is impossible to use the direct access method, and the current transformer should be used for current conversion, and the large current should be converted into a small current, that is, the current that the meter can bear, and then measure. Generally speaking, the secondary side current of the current transformer is 5A, such as 300/5, 100/5. Note: The K2 end of the current transformer is grounded instead of the neutral wire.               


3. Precautions for the connection of the meter: 
      1. The low-voltage energy meter wire adopts insulated copper core wire with a rated voltage of 500V, the current carrying capacity of the wire matches the load, and the wire section is not less than 2.5 square millimeters. 
      2. The laying of plastic insulating wires should be laid with wire codes, plastic grooves or plastic pipes.
      3. The phase sequence of the three-phase three-wire and three-phase four-wire energy meter wires should be marked with yellow, green, and red wires or yellow, green, and red colors painted on the wires to sequence them separately, and if the neutral wire is black, it should not be painted.
      4. When connecting the primary line of the low-voltage current transformer, pay attention to the number of turns and joints of the variable ratio of its logo, and crimp the wire ears.
      5. The wiring of the electricity meter should be based on the drawing accompanying the meter and the wiring diagram on the back of the cover, which is for the new meter. Be especially careful with old watches, the wiring diagram on the back of the cover may not be accurate, because you don't know if the cover is the original match for the watch, or it may have been inadvertently replaced. To be on the safe side, use a multimeter to actually measure and find out the terminals that connect the current coil and voltage coil. The resistance of the general voltage coil is 700-800 ohms, and the resistance of the current coil is 0 ohms. This step is not done well and may lead to a short circuit failure.
      6. When connecting a three-phase four-wire power meter with a current transformer, the three voltage coil connectors on the power meter should be removed, otherwise it will cause a short circuit.

      7. The polarity of the current transformer must be connected correctly. When the wire of the main loop runs from the P1 end to the P2 end, the k1 on the secondary side of the transformer should be connected to the 1st, 4th, and 7th terminals of the power meter, and k2 should be connected to the 3rd, 6th, and 9th terminals respectively. If k1 and k2 are fully connected upside down, they either do not turn (the meter with a check device) or reverse (a meter without a check device). If only one or both of them are connected backwards, the meter will measure less electricity. 

      Winbond Power Technology Co., Ltd. specializes in the production of rail type energy meters, wall-mounted energy meters, digital display multi-functional power meters, of which the wiring method of the guide rail type energy meter is usually down in and out of the top, the transparent shell is generally in and out of the bottom, if there are special requirements, it can be done up and down out, the wiring method of the wall-mounted energy meter is connected according to the convention, the digital display multi-function power meter is the back row has terminals, wired according to the terminals, and there is a wiring diagram on the meter.