User Manual

23
5.1.1 Outputs - Energy measurements – PowerPDU 8QS only
PowerPDU 8QS measures the following electrical parameters every 500ms for Output 1 and for all
outputs together.
The values in the web interface are updated every 5 seconds.
Figure 15 – Measured values – Output 1
Load in watts [W] corresponds to the immediate current and voltage (P = U * I * TPF). It respects the
direction – positive value if the connected device consume the energy or negative value if the
connected device deliver the power back to the power grid (e.g. solar power system).
Current in amps [A] shows the immediate current flowing through the output. Always positive value.
Voltage in volts [V].
TPF (True Power Factor) shows the ratio of active and apparent power, or the ratio of resistance
and impedance. TPF is the ratio of the active power to the apparent power at the power outlet. TPF
shows what portion of apparent power is converted by the load to active power. TPF can be viewed
as the sum of useful power and losses. TPF, unlike PF (Power Factor), also takes into account non-
sinusoidal waveforms. Such distortions of the sinusoidal waveform are caused e.g. by switching power
supplies.
Phase in degrees (°) is the value of a phase shift between current and voltage. Depends on a load
type connected to output. The value 0°/ 360° menas resistive load type.
Frequency in hertz [Hz].
Energy in watt-hours (Wh / kWh) is the cumulative energy consumed over a time interval. The
value is the total consumption at the output since the last reset of the counter.
Reverse Energy in watt-hours (Wh / kWh) is the cumulative energy delivered back to grid over a
time interval. The value is the total power supply at the output since the last reset of the counter.