Common problems Q and A for the smart meters of Sfere Electric


The normal operation of power supply network is very important to social production and life. In recent years, the demand for electricity has increased greatly. The application of energy management, Internet of things and smart grid relying on intelligent power meters has become the focus of future development, and will promote the continuous and rapid development of intelligent power meters. Accordingly, new requirements are put forward for the operation and maintenance of power transformation and distribution. It is very important to find and solve the problems and faults of the power meters in the operation and maintenance in time.




Common problems Q&A for Sfere instruments:

1. The meter doesn’t display when it is powered on

Possible cause: the auxiliary power supply is not added to the instrument.

Solution: use a multimeter to measure whether there is corresponding working voltage on the auxiliary power terminal (1, 2); whether the auxiliary power terminal connection is reliable; whether the fuse of the auxiliary power is damaged or missing.


2. The meter flashes when it is powered on

Possible causes: the power supply voltage exceeds the working range of the instrument, which leads to the power protection of the instrument; the signal input exceeds 120% of the rated value, resulting in the instrument overload and alarm.

Solutions: test whether the auxiliary power supply exceeds the range marked by the instrument; if it exceeds, disconnect the auxiliary power supply; test whether the input signal exceeds 120% of the rated value; test whether the ambient temperature exceeds the upper limit of the operating environment temperature; power on the auxiliary power supply again.


3. Display random code after the meter is powered on

Possible cause: the instrument is greatly interfered.

Solution: turn off the auxiliary power supply and power it on again;


4. Inaccurate display

Possible causes: the transformer transformation ratio is set incorrectly, which does not match the transformer parameters.

Solution: check whether the transformation ratio set by the instrument is consistent with that of PT and CT; whether the rated values of voltage and current are consistent;


5. No response when signal is added

Possible cause: the signal is not really collected by the instrument.

Solution: measure the input signal beside the current and voltage signal terminals of the instrument, check whether the terminal connection is reliable, and whether the current signal is short circuited in the terminal block of the switch cabinet.


6. Three phase instrument phase missing

Possible cause: the signal is not added to the instrument, and the setting does not match.

Solutions: test whether there is a signal input to the meter terminal and whether the terminal connection is reliable; connect the normally displayed one phase signal wire to the corresponding terminal to the missing phase to verify whether there is a problem with the instrument or the peripheral circuit is faulty; check whether the wiring mode of the instrument is consistent with the on-site wiring mode.


7. Inaccurate electric energy measurement

Possible causes: incorrect transformation ratio, wrong phase sequence of voltage and current.

Solution: check whether the transformer ratio set by the meter is consistent with that of PT and CT; check whether the phase sequence of voltage and current is correct; in case of load, check whether there is a negative sign indication for single-phase power through the power display of the meter. If there is a negative sign indication, it is likely that the incoming and outgoing wires of the corresponding phase current are reversed.


8. Inaccurate analog output

Possible cause: The corresponding relationship between the analog output range and the item is incorrect.

Solution: confirm the corresponding relationship between the upper and lower limits of the analog output range; confirm whether the electrical parameters corresponding to the analog output are correct, such as corresponding U, I, P, Q, etc., to ensure that the test equipment is normal; if using PLC, ensure that the PLC analog input wiring is set correctly.


9. Communication abnormal

1) The meter does not send back data

First of all, make sure that the communication setting information of the instrument, such as slave address, baud rate, calibration mode, etc., is consistent with the requirements of the upper computer; if there are multiple instruments in the field without data return, check whether the connection of the field communication bus is accurate and reliable, and whether the RS485 converter is normal. If only one or a few instruments have abnormal communication, check the corresponding communication line. You can modify and exchange the address of the slave machine of the abnormal and normal instruments to test and eliminate or confirm the software problems of the upper computer, or exchange the abnormal and normal instrument installation positions, to eliminate or confirm the instrument faults.


2) The data returned by the meter is not accurate

The instrument communication data includes primary power grid data (float type) and secondary power grid data (int/long type). Please read carefully the description of data storage address and storage format in the communication address table, and make sure to convert according to the corresponding data format. Modscan32 and other software can be used to test instrument communication.


3) Communication indicator status information

In the process of communication test, when the meter receives data, the meter's communication indicator will flash.


If the above methods do not solve your problem, you can log in to the official website or WeChat official account for online consultation, or call Sfere's technical support phone directly: 0510-86199066/86199068, to contact us to solve the problem.




As a high-tech enterprise, Sfere Electric always adheres to the concept of independent innovation, and has made fruitful achievements in patent and software copyright. It has participated in the compilation of national and industrial standards for many times. According to the needs of the enterprise, combined with the practical experience of the field engineering, Sfere Electric will focus on the daily management of the instruments for the maintenance of the enterprise's power operation. Through scientific and effective maintenance methods, it can not only guarantee the integrity of the instruments, but also extend the service life of the instruments, so as to save the operation cost of the enterprise, provide guarantee for the good development of the enterprise, and helping the smooth operation of the enterprise's electricity to create more value!





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