Atec Megger-220072 - Manual

70-, 120- and 160-kV DC
High Voltage DC Dielectric Test Sets
■ Available in analog and digital models
■ Lightest weight available in air-insulated
high-voltage model
■ Advanced performance with long-term
reliability provided by filtered half-wave
rectification
■ Designed for maximum operator safety
70-, 120- and 160-kV DC
High Voltage DC Dielectric Test Sets
DESCRIPTION
The High Voltage DC Dielectric Test Sets (70, 120 and
160 kV) provide the most dependable, portable dc high-
voltage sources for checking the quality of electrical power
cables, motors, switchgear, insulators, transformers and
capacitors. Each portable set (heaviest is 73 lb, 32.8 kg) is
comprised of two separate modules:
Control Module
This module allows the operator to switch-select the
appropriate current output range, adjust the output level
and monitor both the applied voltage and leakage current
at a safe distance from the high voltage being delivered to
the load under test. No voltage higher than input ac power
is present in the control module.
High-Voltage Module
An air-insulated design receives its instructions from the
control unit. It generates the dc high voltage that is
delivered to the load under test.
Although a different control module is used with each of
the three models, they are all the same size and weight.
Each high-voltage module is a different size and weight to
accommodate the rated output voltage.
APPLICATIONS
The dc dielectric test sets are used to make proof tests and
insulation tests on electrical power cables, motors,
switchgear, insulators, transformers and capacitors. Both
types of tests are performed by applying controlled high
voltages to the unit under test at or above insulation
system operating level. Measuring the leakage current
helps determine the unit under test’s ability to withstand
overvoltages such as lightning strikes and switching surges.
The three models described cover a range of output
voltages that meet the most commonly specified ratings
in5-kV to 69-kV class cable. All are suitable for testing
power cable, switchgear and rotating machinery in
accordance with IEEE, IPCEA, NEMA and ANSI guidelines.
Proof Test
Proof testing is used for acceptance testing of newly
installed cable and maintenance testing of aged and/or
repaired cable. For the proof test, the unit under test will
either withstand the test voltage or it will “break down,”
providing the user with a “go/no-go” answer.
Insulation Resistance Tests
To make appropriate tests on healthy insulation, the test
instrument must have microampere sensitivity. Insulation
resistance can be measured in at least three different ways:
The insulation resistance test is often referred to as a “spot
check,” and is performed by applying a predetermined
voltage to the unit under test, holding it until the apparent
leakage current becomes stable and recording the readings
with adjustments for temperature. This test is especially
applicable to low-capacitance units under test.
Digital Model, Cat. No. 220070
Front panel of Analog Model, Cat. No. 220124