GE PQM II, Instruction Manual

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CHAPTER 7: APPLICATIONS
PQMII POWER QUALITY METER – INSTRUCTION MANUAL 7–13
7.4 Triggered Trace Memory
7.4.1 Description
The Triggered Trace Memory can be used to detect and record system disturbances. The
PQMII uses a dedicated continuous sampling rate of 16 samples per cycle to record
fluctuations in voltage or current as per user defined levels. The PQMII calculates the true
RMS value of one consecutive cycle, or 16 samples, and compares this value with the user-
defined trigger levels to determine if it will record all sampled waveforms. The sampled
waveforms include Ia, Ib, Ic, In, Va, Vb and Vc.
Since the PQMII requires a minimum 20 V for detection and has an upper voltage input
limit of 600 V, the following limitation exists for the Trace Memory undervoltage and
overvoltage trigger levels:
FIGURE 7–1: Trace Memory Phase Voltage Trigger Level Limits
0
20
4
0
60
80
100
120
1
4
0
160
0 50 100 150 200 250 300 350
4
00
4
50 500 550 600
NOMINAL VOLTAGE ( V )
TRIGGER
LEVEL
AS
%
O
F
NOMINAL
Ma
xim
u
m
M
i
n
im
u
m