15 Frequently Asked Questions of Digital Multifunction Power Meter
The digital multifunction power meter is a multi-functional smart meter that uses a digital processor and has programmable measurement, display, digital communication, and power pulse transmission output. It can complete power measurement, power metering, data display, collection, and transmission. The multi-function electric meter has functions such as fault alarm, harmonic analysis and data statistics, and time recording. As for the digital multi-function electric meter, there are the dc digital multifunction meters and the ac digital multifunction meters in the world.
The digital multipurpose power meter is widely used in power measurement, management, and evaluation in enterprise settings as well as in the automation of power distribution, intelligent buildings, and substations.
Most of the problems appear during the use of digital multifunction power meters, this article will introduce 15 common problems for you.
1. Double the analog output signal of the digital multifunction power meter
This problem may be caused by the wiring of the system. You must verify the digital multifunction power meter to see if you may use two AO outputs (analog outputs) at the same time while the negative terminals are grounded. If so, the two outputs will interfere with each other. It is recommended to install a signal isolator to solve the problem.
2. The background display of the switch value input of the digital multifunction power meter suddenly breaks and closes, causing false alarms
It may be due to the virtual connection of the auxiliary contact of the switch on the line or the problem of the background setting. You need to check the line and background system settings of the digital multifunction power meter.
3. The switching value input of the digital multifunction power is not closed
It may be due to the phenomenon of virtual connection of the auxiliary contact of the switch on the line or the problem of the background setting. You should check the line and background system settings of the multi-function electric meter
4.The relay output is abnormal
You should check the wiring or relay settings. The relay output has three modes of level, pulse, and alarm, and two output modes of level and pulse. For specific wiring, please refer to the product manual or contact the technical support of the relevant electric meter manufacturer.
5. The digital output signal of the digital multifunction power meter is abnormal
You should check the wiring or digital output settings of the digital multifunction power meter. The digital output methods include energy pulse output and alarm output. For specific wiring, please refer to the product manual or contact the technical support of the relevant power meter manufacturer.
6. There is no problem with the wiring of the digital multifunction power meter but there is no communication
This problem is caused by the instrument settings. You can check whether the address and baud rate of the digital multifunction power meter corresponds to the system software. There must be no overlap in the addresses and a constant baud rate across all devices connected to the same communication channel.
7. The backlight of the digital multifunction power meter is flickering
You can check the instrument alarm settings. Some instruments will flash backlight in an alarm state. If the instrument is in an alarm state, the backlight of the instrument will flash, and after the alarm is canceled, the backlight will return to normal.
8. The digital multifunction power meter cannot enter the parameter setting
It is possible to set the password unintentionally. Please contact technical support for help.
9. The display of current and voltage is correct, but the display of power is abnormal
This problem is caused by voltage or current wiring. You should carefully check whether there is a phase interchange or reverse connection in the voltage or current wiring of the digital multifunction power meter.
10. The digital multifunction power meter has no display
You should confirm whether the power supply voltage is input normally. You need to check whether there is a virtual connection in the incoming line of the digital multifunction power meter power supply and use a multimeter to measure whether the voltage of the incoming line terminal of the multi function electric meter is normal. The positive and negative poles of the DC power supply should be distinguished. In addition, pay attention to whether the output power of the power supply meets the requirements. Make sure that the appropriate auxiliary power supply (AC/DC85-265V) has been added to the auxiliary power supply terminal of the instrument. Auxiliary power supply voltage exceeding the specified range may damage the instrument and cannot be restored. You can use a multimeter to measure the voltage value of the auxiliary power supply. If the power supply voltage is normal and there is no display on the digital multifunction power meter, you can consider powering it off and on again.
11. The digital multifunction power meter fails to display the required functions
You need to check whether this model multifunction meter contains this function. The ordered multi function electric meter should understand the functions contained in it. Different models have different functions, so blind wiring and blind use should not be used.
12. The displayed value of current and voltage is too large or too small (there is a multiple relationship with the actual value)
The CT and PT transformer ratios of the digital multifunction power meter itself are not set. You can check the user manual or contact technical support directly to help solve the problem.
13. There are some obvious errors in the voltage and current display values (for example the B-phase voltage is too large)
It may be a problem to set up the wiring method of the digital multifunction power meter. You should change the wiring mode of voltage or current according to the actual wiring of the system in the instrument settings
14. The measured values of U, I, P, etc. are inaccurate
It may be a wiring problem or a setting problem. First of all, you need to make sure that the correct voltage and current signals have been connected to the digital multifunction power meter. You can use a multimeter to measure the voltage signal and use a clamp meter to measure the current signal when necessary. Secondly, make sure that the connection of the signal line is correct, such as the terminal with the same name as the current signal (that is, the incoming line terminal), and whether the phase sequence of each phase is wrong. The digital multi-functional power meter can observe the power interface display, only in the case of reverse power transmission, the active power data is wrong, and the active power data is wrong in general use. If the active energy sign is negative, it is possible that the current input and output lines are connected incorrectly. Of course, the wrong phase sequence connection will also cause an abnormal power display.
In addition, it should be noted that the power displayed by the digital multifunction power meter is the value of the primary grid. If the multiplier of the voltage and current transformer set in the digital multifunction power meter is inconsistent with the multiplier of the actual transformer, it will also cause an inaccurate power display on the meter. The voltage and current ranges in the digital multifunction power meter are not allowed to be modified after leaving the factory. The wiring network can be modified according to the actual connection method on site, but the setting of the wiring method in the programming menu should be consistent with the actual wiring method, otherwise, it will also cause wrong display information.
15. The electric energy of the digital multifunction power meter is inaccurate
It may be a wiring problem. The digital multifunctional power meter’s electric energy accumulation is dependent on the measurement of power; thus, you should first check to see if the multifunctional meter’s power value corresponds to the actual load. The digital multifunctional power meter supports two-way electric energy measurement. In the case of wrong wiring and the total active power is negative, the electric energy will be added to the reverse active electric energy, and the forward active electric energy will not be accumulated. The most frequent problem in field use is the reverse connection of the incoming and outgoing wires of the current transformer. The digital Multi-function power meters can see the phase-separated signed active power, if the power is negative, it may be the wrong wiring. In addition, the wrong connection of the phase sequence will also cause the abnormality of the electric energy of the digital multifunction power meter.
Generally speaking, there are four kinds of general instrument failures: setting problems, wiring problems, interference problems, and instrument failures. Before encountering problems, you can carefully refer to the instruction manuals of the digital multi-function power meters of various manufacturers to check whether there are no problems in related functions, wiring, settings, etc.