DNP3 Manual
M6xxD/EN M/B
M6xx
Page 12
2 ELEMENT EQUATIONS (5Amp CTs) :
The above equations provide answers in fundamental units (VOLTs, AMPs, WATTs, VARs, VAs and Hz).
If the user desires other units such as KILOVOLTS, KILOWATTS or KILOVARS, the answers given by
the equations should be divided by 1,000. If the user desires MEGAWATTS or MEGAVARS, the answers
given by the equations should be divided by 1,000,000. Energy values are in units of kWh or kVARh.
1.7 Primary Units
An option exists to choose Primary Units instead of the pre-existing scaling mode, 'Optimal Resolution'
adding the concept of 'scaling modes' to M6xx. The pre-existing scaling mode is called 'Optimal
Resolution' on the basis that resolution of the protocols are optimized based on secondary full scale and
therefore independent of CT and VT settings. The 'Primary Units' mode creates protocol values that
include CT and VT settings, which requires the user to choose a scaling factor (in multiples of 10). The
scaling factor must be selected such that it achieves the desired resolution and does not cause an
overflow in the protocol value. The Scaling mode selection and the scaling factors are maintained
separately for both Modbus and DNP and are configured on the Settings/Protocol webpage. Below is a
screen shot and explanation of the Primary Units mode:
Max
Min Max
Min Max
*
(Inst, Fund, Demand,
)
RATIO
RATIO
L-L (Inst, Demand,
,
)
*
RAT
TOTAL (Inst, Demand,
,
)
Value
=
x
x
AMPEREs
10
CT
32768
Value
=
x 150 x
VOLTs
PT
32768
Value
WATTs (VARs) (VAs
=
x
x
)
3000
32768
Max
IO
RATIO
(True, Displacement)
(Amps, Volts, Inst, Demand,
)
x CT
PT
Value
FREQUENCY =
100
Value
POWER
=
FACTOR
1000
kWh (kVARh) = Value
Value
THD,
=
TDD
10
Value
K - Factor =
100
* For One Amp CT Option, divide this value by 5
