Frequently Asked Questions about Instruments

1. The meter has no display. The reason for the fault is judged: confirm whether the power supply voltage input is normal; Solution: check whether there is a virtual connection of the meter power input line, use a multimeter to measure whether the voltage of the meter input terminal (L+, N-) is normal and meets the order requirements , DC power supply should distinguish positive and negative poles, and pay attention to whether the output power of the power supply meets the requirements. 2. The meter fails to display 1. The meter does not display. The reason for the fault: Confirm whether the power input is normal; Solution: Check whether there is a virtual connection in the power supply line of the meter. Use a multimeter to measure the input terminal (L+, N-) Whether the voltage is normal and meets the order requirements, the DC power supply should distinguish between positive and negative poles, and also pay attention to whether the output power of the power supply meets the requirements. 2. The meter fails to display the required function. Failure reason judgment: Check whether this model meter contains this function; Solution: The meter ordered should understand the functions it contains. Different models have different functions, so you should not blindly wire or use it blindly. 3. The displayed value of current and voltage is too large or too small (it has multiple relationship with the actual value). Fault cause judgment: the CT and PT transformer ratio of the instrument itself is not set; solution: you can check the user manual attached with the meter or directly Call technical support for help. 4. There are some obvious errors in the voltage and current display values u200bu200b(for example: B-phase voltage is too large). The cause of the fault is judged: it may be a problem with the wiring method; the solution: the voltage or current wiring method is set in the instrument setting according to the actual wiring of the system Correctly changed. 5. The current and voltage display is correct, and the power display is abnormal. The cause of the fault is judged: the voltage or current wiring problem; the solution: carefully check whether the voltage or current wiring is interchanged or reversed. 6. There is a large error between the electric degree measurement and the actual value or no measurement at all. Fault judgment: wiring error; solution: check whether the voltage and current wiring has the wrong direction or the three-phase A, B, and C do not correspond (for example: Phase A voltage corresponds to phase B current). 7. Judgment of the cause of the fault that the power is not memorized: the power-on time is too short, less than the minimum saving interval of the power; the solution: the power-on stability holding time of the EV/DV100 series is not less than 400 seconds, and the other series power-on stability holding time is a lot In 2 seconds. 8. There is no problem with the instrument wiring but no communication failure. Cause judgment: instrument settings; solution: check whether the instrument setting address and baud rate correspond to the system software. All instruments connected to the same communication channel must ensure that their addresses do not overlap. The special rate is the same. 9. The analog output signal is doubled and the cause of the fault is judged: it may be caused by the system wiring; the solution: whether to use two AO outputs at the same time and the negative terminal is grounded at the same time, if it is, the two outputs will interfere with each other, it is recommended to install The signal isolator is solved. 10. The background display of DI switch input is switched off and on, and false alarm. Fault judgment: It may be due to the phenomenon of virtual connection of the auxiliary contacts of the switch on the line or the problem of the background setting; solution: check the line and background system settings.