5
OPERATING INSTRUCTIONS
continued
Phasing Measurements
We recommend that two person crews take the readings. Since the operation is occurring
near two energized conductors, the use of two person crews allows each person to operate
one stick and maintain high safety standards.
In order to take a reading, each probe must contact an energized line. Be sure that only
those probes intended for the particular application are used (see page 6). Always keep
the connecting cord free and clear of energized phases and ground.
The phase rotation meter requires three connections for proper operation. Always connect
the ground lead first and only to a known good ground. After testing is complete, be
certain to remove and isolate the main contact probes from all voltage sources prior
to disconnecting the ground lead.
Take the Readings
To determine which of the two phases is leading or lagging, two separate readings
are required.
READING 1:
Place one probe (resistor stick) on each of the two phases being
tested and take a reading.
READING 2:
Reverse the probes (resistor sticks) so that they contact the same
two phases but in the opposite direction, and take a reading.
FOR EXAMPLE:
If in Reading 1 the probe with the meter on it was contacting Phase A
and the probe with the junction box was contacting Phase B, then
reverse them so the probe with the meter on it contacts Phase B and
the probe with the junction box contacts Phase A.
Determining the Results
The resistor stick with the meter on it will show a higher indication when it is in contact
with the leading phase. The meter indicates relative phase rotation. The resistor stick with
the meter on the leading phase will indicate a reading of up to 100 at the maximum
voltage for the range selected. The resistor stick with the meter on the lagging phase
will indicate about 60% of the leading phase reading
For three phases there are three pairs of phases, so any two pairs should
be tested as outlined above. For example, with three Phases A, B and C:
1. Test Phases A and B. A is determined to be leading B.
2. Test Phases A and C. C is determined to be leading A.
Now, A leads B from Step 1. C leads A from Step 2. Therefore, the rotation is
C-A-B. This can also be written as A-B-C. This can be verified by testing the
third pair of phases. Test Phases B and C. B is determined to be leading C.