The multifunction power meter is a multifunctional smart meter with programmable measurement, display, digital communication and power pulse transmission output. It can complete power measurement, power measurement, data display, acquisition and transmission. Multifunctional power meters are widely used in substation automation, distribution automation, intelligent buildings, and power measurement, management and assessment within enterprises. The measurement accuracy is 0.5. It can realize LED on-site display and remote RS-485 digital interface communication. It uses a communication protocol.
1. Measuring components, such as voltage transformers and current transformers.
2. Power components, which mainly provide power to the system.
3. Measurement and control components, which mainly calculate the measured signals and control the output switch signal.
4. Display components, which display the measurement and measurement.
5. Communication components for easy networking.
6. Other components. Switch, input, output, 4-20ma signal, etc.
The multifunction power meter has two main functions: measurement and metering.
1. Measurement: It can measure voltage, current, active power, reactive power and power factor.
2. Metering: It can measure the total power consumption, peak, flat and valley power consumption. The monthly electricity can be counted and the monthly meter reading time can be set.
If the measurement of the multifunction electric energy meter is abnormal, the electric energy meter may be damaged on the one hand, and the fault may be caused by the poor wiring of the instrument or the transformer on the other hand. So how to judge and exclude it?
When the active power P value of the multifunction instrument is negative, and the measurement of electric energy, power and power factor is wrong, it can be eliminated according to the following two methods.
Method 1: Determine whether the wiring of the multifunction instrument terminal is faulty.
Under normal circumstances, the phase sequence of the multi-function power meter is Ua-Ia; Ub-Ib; Uc-Ic.
If the power is negative and the power factor and electric energy are wrongly measured, first check whether the phase sequence of the terminals of the multifunction power meter is normal. If not, please power off and reconnect. If the phase sequence is normal, but the meter data is abnormal, please check whether the incoming and outgoing wires of the secondary side of the current transformer are connected correctly.
Method 2: Determine whether the wiring of the incoming and outgoing wires of the secondary side current transformer is faulty.
If the active power P value of the multi-function power meter is negative and the measurement of electric energy, power and power factor is wrong, we first rule out whether it is a wiring fault in the incoming line of the power meter. If the wiring of the incoming terminal of the instrument is normal, we will check whether the wiring of the secondary side current transformer is normal. Under normal circumstances, the connection method of the incoming and outgoing wires of the current transformer: Ia+ incoming wire, Ia- outgoing wire; Ib+ incoming wire, Ib- outgoing wire; Ic+ incoming wire, Ic- outgoing wire.
If the wiring of the secondary side of the current transformer is faulty, the following phenomena will occur:
(1) The active power is negative.
(2) Abnormal energy metering.
(3) Abnormal power factor.
If the above two fault reasons are eliminated, and the above fault phenomenon still occurs in the multifunction instrument, please contact the instrument manufacturer.
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