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4.
Testing
A phase comparison is carried out in order to find the in-phase condition of three
phase current installations. The phase comparison is usually carried out at the isolating
point of
two networks,
two systems
two system parts
two lines
which are supposed to be interconnected. Following, the expression system will be
used in this context (see Fig. 4).
4.1 Test Procedures
The following test procedures are required for a definite phase comparison. They have
to be carried out completely, except the test has to be interrupted. The order indicated
has to be observed.
For testing, the respective test electrode has to contact the blank installation. During
the test it has to be observed that only the test electrode contacts
- the live installation,
- earthed installation and
- non-earthed installation (see page 36).
The indication Out of Phase comes up at the PHV I Phase Comparator if the phase
angle between the systems to be tested (system parts) is between 60° and 300°.
System 1
System 2
Fig. 4
L1
L2
L3
L1
L2
L3
