D e lt a M u lt i- C ir c u i t P o w e r M e t e r D P M - M A11 2 1 U s e r M a n u a l
6 - 2
_6
6.1
Common Malfunction Analysis
6.1.1
Power Meter doesn’t Work after It’s Electrified
Make sure voltage and other wiring is correct, voltage should be in the functional range.
Turn off the meter and then turn it on.
6.1.2
Voltage or Current Reading Is Incorrect
Check that the wiring mode settings match the actual wiring mode.
Check that the hall current transformer (Hall sensor) variable ratio is set correctly.
。
Check that the GND is correctly grounded
Check that the hall current transformer (Hall sensor) are intact.
6.1.3
Power or Power Factor Reading Is Incorrect, but Voltage and
Current Reading Are Correct
Compare voltage and current inputs to the actual wiring and wiring diagrams and check the phase relationship is
correct.
6.1.4
RS-485 Communication Is Unusual
Check that the communication string transfer rate, ID, and communication protocol settings of the upper machine
are consistent with the meter.
Please check the data bits, stop bits and parity bits that the settings are consistent with the master computer.
Check if RS-485 converter is working.
Check the entire communication wiring for problems
（
short circuit
、
broken circuit
、
ground
、
cover wire for correct
single-end ground, etc
）。
Turn off power meter and master computer, then restart it.
If the communication line is long, it is recommended to parallel a matching resistance of about 120 ohms at the end
of the communication line.
