The Megawatt Option; Before You Use The Megawatt Option - Siemens 9200 Features Manual

9200 Features Guide

The Megawatt Option

The Megawatt option displays all power and energy values in millions
(e.g. megawatts) and volts in thousands (kilovolts). The Megawatt option
has a different front panel faceplate than the standard meter, with labels
for kV, MW, MVA, MVAR, MWh, MVAh, and MVARh.

Before You Use the Megawatt Option

In addition to setting up the PT1 and PT2 registers on your Megawatt
option, you must set the PTS (PT Scaling) register to "x1000." This allows
communications software to correctly interpret megawatt and kilovolt
quantities, and enables meaningful measurements through the meter
front panel.
You must set the PTS register
to "x1000" for the Megawatt
option to operate correctly.
To learn about meter configuration, refer to the 9200 Installation and Basic
Setup Instructions section "Front Panel Navigation"—"Configuration Mode."
What Does the PT Scaling (PTS) Setup Register Do?
The PT Scaling setup register provides an additional PT primary register to
accommodate a larger PT ratio. PTS offers a "x1000" quantity for the PT
primary register. (The standard meter model uses the "x1" default scaling.)
How PT Scaling Defines the PT Ratio
Suppose that a meter with the Megawatt option is applied to measure
power on a 500 kV system, the voltage applied to the PT primary is 288
kV, and the expected voltage on the PT secondary is 120 V. The formula
below shows how these values are used with the PT Scaling register set at
"x1000" to define the overall PT ratio.
PT Ratio =
PT Ratio =
The formula shows that the meter correctly measures 288.0 kV when PTS
is set to "x1000," PT1 is set to 288, and PT2 is set to 120.
6
Pt1
t P S
Pt2
PT Primary
PT Secondary
288,000
120
PT1 (Primary)
PTS (Scaling)
PT2 (Secondary)
PT1 x PTS
PT2
288 x 1000
120