dehn PHV 1 P Instructions For Use Manual page 28

2.10 The PHV 1 P phase comparator may only be used for three-phase systems.
2.11 The PHV 1 P phase comparator may be used and stored according to climatic category N and W.
Climatic category N: -25 to +55°C (temperature) and 20 to 96% (relative humidity)
Climatic category W: -5 to +70°C (temperature) and 12 to 96% (relative humidity)
2.12 Phase comparison is not possible if an earth fault is present in the system.
2.13 The PHV 1 P phase comparator may only be used in voltage systems with a frequency of 50 Hz.
The single-pole measuring principle basically requires high frequency stability. The following
frequency conditions must be fulfilled:
The power frequency must be between 49.9 Hz and 50.1 Hz.
Frequency fluctuations during the measurement 2 ≤ mHz/s
If one condition is not fulfilled, phase comparison is not possible or the PHV 1 P phase compara-
tor interrupts the measurement.
2.14 In case of angled or confusing conductor arrangements, interference fields may negatively affect
the phase comparison or interrupt the measurement. Such measuring points must be avoided or
it must be checked whether they are suited for phase comparison. To prevent interruption, it is
advisable to contact the most critical points first.
2.15 The phase comparator must be handled in such a way that the user always keeps a sufficient
safety distance from all parts of the installation which may be energised.
2.16 Tampering with or modification of the PHV 1 P phase comparator as well as attaching labels or
other components is impermissible.
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