ALL-TEST PRO ATPOL II, Руководство пользователя

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Check Voltage Phase Sequence
– Using PSM
While still viewing all voltage waveforms of a three-phase system,
notice in what order they reach their peak value. Normally, the order
should be 1-2-3. In other words the highest level of the V
1N
(or V
12
)
waveform will be followed next by the highest level of the V
2N
(or V
23
)
waveform, which will be followed by the highest level of the V
3N
(or
V
31
) waveform (see the example).
An order of 2-3-1 or 3-1-2 is the same as a 1-2-3 sequence; the
reference point just starts at a different place (for instance 2-3-1 is
just a portion of the continuing sequence of 1-2-3-1-2-3). Sometimes
an order of 3-2-1 is correct. Some utilities deliver power in that
sequence and sometimes a motor will be connected in that manner to
make it spi
n “backwards”. An order of 2-1-3 or 1-3-2 is the same as
3-2-1, the reference point just starts in a different place (for instance
2-1-3 is a portion of the continuing sequence of 3-2-1-3-2-1).
Checking Current Levels
– Using PSM
Next click on the blue
“Back Arrow” icon and select “Current”, “Set All”, and “View”.
Now that you are viewing the current waveforms, there are several questions that
need to be answered.
First, are the sizes of each of the three phases reasonable
(depending on the type of load, currents of each phase may be
very similar or fairly different)? The RMS value of each waveform
is listed in the heading of the graph (such as “I
1
” with “136.5”
beneath it, indicating that I
1
=136.5 amps), similar to how they are
presented for voltage as seen in the Checking Voltage Levels
section. Also check the shapes of the current waveforms. Some of the more common current
waveforms that may be seen are shown in the
Checking Phase Lag
– Using PSM
section below.
Checking I Phase Sequence
– Using PSM
While still viewing all current waveforms of a three-phase system, notice how they reach their peak
value. Each of the peaks should be the same distance from each other (similar to as shown in the
Checking Voltage Sequence
– Using PSM section). This even spacing must continue across the
screen. In a three-phase system there will be a constant 120 degrees apart (5.5 msec for 60 Hz, 6.3
msec for 50 Hz). If one or two of the current probes is backwards, the peaks will not be evenly spaced.
If that is the case, determine which probe can be turned around to get the spacing correct. After turning
it around and verifying that the spacing is now correct, determine in what order the currents reach their