Registration Of Quantities; Kwh; Kvarh; Kvah - Elster A1140 User Manual

10.1

Registration of Quantities

10.1.1

kWh

kWh total import (active energy)
kWh total export (active energy)
Total import and total export quantities are registered
separately. The measurement discrimination is such that,
as the power factor of any load from 0.05Ib to Imax is
varied over 360°, the import and export registers will never
advance together. The resolution of registration is 1mWh.
10.1.2

kvarh

Q1 kvarh Inductive Import
Q2 kvarh Capacitive Import
Q3 kvarh Inductive Export
Q4 kvarh Capacitive Export
All four quadrants are registered separately. The resolution of registration is 1mvarh.
kvarh is derived using the phase shift method.
Note: The diagram shows a representation of the quadrants. The active quadrant can be shown on
the display.
10.1.3

kVAh

kVAh is derived from the measured kWh and kvarh values
The calculation uses the formula: kVAh = √ ([kWh]
There are two kVAh registers. These can each be configured to accept pulses from
any combination of quadrants e.g.
Q1
kWh *
kvarh *
Note: Real and reactive energy for each phase is respectively summated prior to kVAh
calculation.
Q2 Q3 Q4
*
*
Operating & Maintenance Instructions
-P
2 2
+ [kvarh] )
kVAh - to match 2 electromechanical meters
13
+Q
Q2 Q1
+P
Q3 Q4
-Q