Chapter 5
Configuring
the EM13X Series
General Meter Setup
84
EM13x Series SMART MULTIFUNCTION METER
Figure
5-7: General Setup Dialog Box – Device Options Tab
Power Calculation Modes
The power calculation mode option allows you to change the method
for calculating reactive and apparent powers in presence of high
harmonics. The options work as follows:
When the reactive power calculation mode is selected, active and
reactive powers are measured directly and apparent power is
calculated as:
2
2
Q
P
S
This mode is recommended for electrical networks with low harmonic
distortion, commonly with THD < 5% for volts, and THD < 10% for
currents. In networks with high harmonics, the second method is
preferable.
When the non-active power calculation mode is selected, active
power is measured directly, apparent power is taken as product S =
V x I, where V and I are the RMS volts and amps, and reactive power
(called non-active power) is calculated as:
2
2
P
S
N
Configuring Digital Inputs
The EM13X Series can be provided with two digital inputs (standard)
and 4, 8 or 12 optional digital inputs that can be linked to control
setpoints to give an indication on input status change (see
Configuring
Alarm/Control Setpoints
), or can be linked to general pulse counters to
count incoming pulses (see
Configuring Counters
). They can also be
linked to the Billing/TOU registers to count pulses from external
wattmeters or gas and water meters.
