Megger PVS 100i, Руководство пользователя

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7.2 Electrical Connection of the Mobile Unit
7.2.1 Power Supply
The mobile unit can be operated through the mains voltage as well as through the
battery (see section 5.2).
The advantage of using the mains supply is that GSM and GPS reception does not have
to be ensured over the entire course of the measurements. Instead, the mobile unit
synchronises itself with the base station only at the start of a measurement and
subsequently uses its own supply voltage as the reference phasing.
Mains operation is especially recommended in buildings with extremely limited GSM
and GPS reception. Using an adequately dimensioned extension cable, one can go
in front of the building with the mobile unit in order to prepare the measurement
under conditions of good reception quality. After the measurement has been started
and the GSM connection ended automatically, one can then go back inside the
building and connect with the test voltage without having to consider the factor of
reception quality. The phase of the test voltage is determined based on the phasing
of the local supply voltage. The mains voltage connection must remain connected
throughout the entire procedure!
7.2.2 Voltage Tapping
Depending on the voltage level at which the phase identification is to be performed, the
voltage must be tapped in an appropriate manner. The PVS 100i offers the following
options for this:
• Direct connection to low voltage lines up to 400 V via measuring cables (see
section 7.2.2.1).
• Connection to capacitive test points of enclosed switchgear (see section
7.2.2.2).
• Use of the high voltage sensor HVS 120/36i for tapping the test voltage on
overhead lines or components up to 120 kV system voltage (see section
7.2.2.3).
As is the case with other electric measurement devices, under certain circumstances
the PVS 100i displays measurement values on the basis of electrical fields, despite
there being no connection to the measurement object. This is absolutely normal and
does not suggest any malfunction of the device. In order to prevent any erroneous
measurements or mix-ups, it is imperative that the user ensures reliable voltage
tapping.