Three Phase Meter Box Wrong Wiring And Precautions

Three Phase Meter Box Watt-hour meter is the main performance of the wrong line: power meter reversal, do not turn, slow speed and so on. As the energy meter metering device is composed of energy meter, transformer, secondary circuit and other components, therefore, the energy meter error measurement and its correction is also a variety of changes. It is an important subject in front of the employees of power supply enterprises, which is an effective way to improve the image of power supply enterprises and reduce the loss of electricity for fairness, fairness and reasonable measurement of energy, timely, fast and correct diagnosis of wrong wiring and take effective preventive measures. I combined with the installation of electricity and electrical energy metering device to check the operation of the practice, talk about the typical error meter wiring and prevent the measures for peer reference.

First, the power metering device common wrong wiring

1, Single-phase active energy meter error wiring

When the direct access to the single-phase energy meter table, the error will be into the energy meter and the zero line of the line of fire, the zero line from the energy meter after the break in the state, and the load across the line of fire and ground , Electricity is still normal, because the current meter current coil without current through the turn.

When the voltage off the hook or poor contact caused by open circuit,Three Phase Meter Box when the power meter measurement power P = U (0) × Icosφ = 0, the meter does not turn. When the current transformer secondary test open circuit, the current meter current coil without current through the power meter to measure the power P = U (0) × Icosφ = 0, the meter does not turn. Similarly, the current transformer secondary side of the short circuit, due to no current through the current coil, the meter will not turn. When the current transformer secondary polarity reversed, the power meter to measure the power P = -UIcosφ, power meter reversal.

2, Three-phase three-wire two-part energy meter wrong wiring

When the voltage line A, B phase voltage on the tone; B, C phase voltage swap; A, C phase voltage on the tune, the measured value of P are zero, the energy meter does not turn.

3, Three components of the wrong meter wiring

When any current line or TA polarity is reversed,Three Phase Meter Box the active power of the reverse phase measurement is negative and the energy meter becomes slower.

When there are two-phase current line or TA polarity reversed, the measured value of the reverse phase is negative, the meter is reversed.

When the three-phase current line or TA polarity reversed, the energy meter reversal, K = -1.

When the current loop is open, the meter only measures the two-phase power; two-phase open circuit, only measure a phase power; three-phase open, the energy meter stops. Similarly,Three Phase Meter Box the current loop appears a phase, two-phase, three-phase short circuit, the meter with the same value.

When the low-voltage three-phase four-wire energy meter TA wiring is correct, and the voltage auxiliary line phase sequence and the current does not match, such as energy meter reversal.

In the voltage circuit there is an open circuit fault, there are the following characteristics: a phase voltage circuit open circuit, the meter to measure the two-phase power; two-phase voltage circuit open circuit, the meter only measure a phase power, power meter slow; three-phase voltage circuit open When the meter stops.

Second, the specification of energy meter metering device installation wiring and technology

It is an effective means to prevent the measurement error from regulating the installation wiring of the electric energy metering device. First,Three Phase Meter Box the secondary circuit of the energy metering device should meet the technical requirements: high-pressure TA wiring, should not be simplified wiring, and the application of split-phase wiring, that is, three-phase three-wire two TA with four lines, three-phase system with three Root connection. For some of the low-voltage still use the simplified wiring, that is,Three Phase Meter Box three-phase three-line two TA with incomplete star connection, with three lines connected; three-phase four-wire three TA-star method wiring, with four lines.

Second, when the TV secondary voltage line with the cable connection, the general use of four-core, a core as a backup, 35kV or more charge TV secondary circuit, should not install the isolation switch auxiliary contact, but the installation of fuses; 35kV and below charge TV secondary circuit,Three Phase Meter Box shall not be equipped with isolation switch auxiliary contacts and fuses; 35kV and below users of the application of special measurement transformer; 35kV and above users should have TA, TV dedicated secondary circuit, not with the protection, Measurement loop common.

Secondary circuit connection wire is best to use yellow, green, red color line, neutral line with black wire, and the middle of the wire shall not have joints. Wire connection for the screw crimping, screw crimping,Three Phase Meter Box the thread should be bent ring, the direction of screw tightening with the same direction.