ROOTECH ACCURA 3300E, User Manual

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Accura 3300E User Guide Chapter 4 Measurements
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2015 Rootech Inc. All Rights Reserved
Page 79
Power Factor(PF) Measurement
Power factor is calculated as the ratio of active power to apparent power. Sign of power factor
becomes positive or negative value according to the sign of active power. Positive power factor
means the received status and negative means the delivered status. In case that apparent power is
0, power factor cannot normally calculated. For this case, display configuration as 1.0 or 0.0 is
possible and it is default configured to display as 1.0.
𝑃𝐹
𝑎
=
𝑃
𝑎
𝑆
𝑎
, 𝑃𝐹
𝑏
=
𝑃
𝑏
𝑆
𝑏
, 𝑃𝐹
𝑐
=
𝑃
𝑐
𝑆
𝑐
𝑃𝐹
𝑡
=
𝑃
𝑡
𝑆
𝑡
Sign of power factor can be removed by configuration. In this case, the status[received/delivered]
cannot be recognized only by power factor. Power factor without sign is as follows.
𝑃𝐹
𝑎
= |
𝑃
𝑎
𝑆
𝑎
| , 𝑃𝐹
𝑏
= |
𝑃
𝑏
𝑆
𝑏
| , 𝑃𝐹
𝑐
= |
𝑃
𝑐
𝑆
𝑐
|
𝑃𝐹
𝑡
= |
𝑃
𝑡
𝑆
𝑡
|
LEAD/LAG of Current Phase
The relationship between power sign and current phase LEAD/LAG for 4 quadrant phase angle of
voltage and current is shown below. When reactive power[Q] is 0, status is neither LEAD nor LAG.
Fig 4.8 Power Sign and Current Phase LEAD/LAG
P
Q
LAG
LAG
LEAD
LEAD
PF(+)
PF(+)
PF(-)
PF(-)
+0.0 -0.0
+1.0 -1.0
-0.0 +0.0
Note
The phase difference(LEAD/LAG) between current and voltage is displayed on the power factor
display screen of Accura 3300E. When reactive power is 0, the status is not displayed.