CCS WattNode Pulse Output, Инструкция по установке и эксплуатации

Страница: 17 / 20

Operating Instructions 15
Operating Instructions
Power and Energy Computation
The power is a function of the pulse frequency, while the energy is a function of the count of pulses. The
variable
nCTs is the maximum number of CTs that the WattNode model can use. The variable CTAmps is
the full-scale current rating of the CTs. Note: If the wires being measured are passed through the CT(s)
more than once, then the full-scale CT current is divided by the number of times that the wire passes
through the CT.
VAC is the nominal phase voltage of the WattNode model. The variable PulseFreq is the
pulse frequency from the WattNode, while Pulses is the total accumulated count of pulses. FSHz is the
full-scale pulse frequency printed on the rear label of the WattNode. The values of the constant parameters
are in the following table.
WattNode Model(s) Possible FSHz Values nCTs VAC
WNA-1P-240-P 2.667, 193.3, or 773.3 Hz 2 120
WNA-3Y-208-P 4.000, 290.0, or 1160 Hz 3 120
WNA-3Y-400-P 4.000, 290.0, or 1160 Hz 3 240
WNA-3Y-480-P 4.000, 290.0, or 1160 Hz 3 277
WNA-3Y-600-P 4.000, 290.0, or 1160 Hz 3 347
WNA-3D-240-P 2.667, 193.3, or 773.3 Hz 2 240
WNA-3D-480-P 2.667, 193.3, or 773.3 Hz 2 480
Table 2: Power and Energy Parameters
Below are the equations used to compute the power and energy.
Power(W) =
Energy(WH) =
nCTs · VAC · CTAmps · Pulses
nCTs · VAC · CTAmps · PulseFreq
FSHz
FSHz · 3600
The following table provides an alternate means of computing the power and/or energy being reported by a
WattNode.
WattHours per Pulse per CT Rated Amp
Full-scale Pulse
Model Frequency
2.667 or 4.0 Hz 193.3 or 290 Hz 773.3 or 1160 Hz
WNA-1P-240-P 2.500 × 10
-2
3.448 × 10
-4
8.621 × 10
-5
WNA-3Y-208-P 2.500
×
10
-2
3.448
×
10
-4
8.621
×
10
-5
WNA-3Y-400-P 5.000
×
10
-2
6.897
×
10
-4
1.724
×
10
-4
WNA-3Y-480-P 5.771 × 10
-2
7.960 × 10
-4
1.990 × 10
-4
WNA-3Y-600-P 7.229
×
10
-2
9.971
×
10
-4
2.493
×
10
-4
WNA-3D-240-P 5.000
×
10
-2
6.897
×
10
-4
1.724
×
10
-4
WNA-3D-480-P 1.000 × 10
-1
1.379 × 10
-3
3.448 × 10
-4
Table 3: WattHours per Pulse
Example: a WNA-3Y-208-P with 15 amp CTs and a full-scale pulse frequency of 4 Hz will output 1 pulse
for every 0.375 WattHours.
(2.500 × 10
-2
)•(15.0 amps)•(1 pulse) = 0.375 WattHours