PQube User Manual 2.1
Page 42 of 113
Distortion: These meters show the Total Harmonic Distortion (THD) of the voltage and
Total Demand Distortion (IEEE 519 TDD) of the current (if you have an optional current
sensing module installed).
Unbalance: These meters show the voltage unbalance and the current unbalance (if you
have an optional current sensing module installed). You choose in your Setup.ini file
whether your PQube calculates unbalance using the ANSI C84.1 method, or the IEC
method, or the GB method.
Flicker: These meters show flicker (IEC 61000-4-15). P
inst
is the instantaneous flicker value
for Incandescent Flicker in IEC 61000-4-15. P
ST
is the short term flicker, a statistical analysis
of Pinst after 10 minutes, synchronized to real-time clock. P
LT
is the mean value of P
inst
over
previous 2 hours, synchronized to real-time clock.
Power: These are the true power readings, and they correctly handle harmonics (distorted
voltages and distorted currents). If you have set a current transformer ratio and/or
potential transformer ratio in your Setup.ini file, then these meters will use those ratios, so
these meters can show their values in kilowatts, megawatts, or even gigawatts.
Energy: These three meters show the total energy, apparent energy, and carbon since the
last reset of these meters. You can reset these meters by holding down the select button
for 3 seconds. The date of the last reset will appear on the screen. You can reset these
meters by holding down the select button for 3 seconds. The date of the last reset will
appear on the screen.
Energy: Access this screen by moving the joystick down from the Energy screen above.
Here, you can view energy in large digits specified in ANSI C12.20.
Carbon: This meter shows the intensity of carbon dioxide output, based roughly from the
EPA’s measurements for typical California, USA values. You may edit these values in the
Setup.ini file as necessary.
Peak amps: These three meters show the cycle-by-cycle highest RMS amps; the 1-minute
interval with the highest RMS amps; and the N-minute interval with the highest RMS amps.
(The highest RMS amps value is determined by looking at the highest among all of the
active phase conductors. It excludes the neutral conductor.) The N-minute reading is
usually set to 15 minutes, but you can set it to a value between 3 minutes and 60 minutes
in your Setup.ini file. The 1-minute and N-minute readings are automatically synchronized
to your PQube’s real time clock. These readings can be useful for evaluating inrush current
and circuit breaker settings, and for sizing power conditioning devices such as UPS and
voltage regulating transformers. You can reset these meters by holding down the select
button for 3 seconds. The date of the last reset will appear on the screen.
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