Atec Megger-MIT515 - Manual (Page 2)

■ Locking test leads provide additional safety.
■ 3 mA short circuit current with unique max power
regulations technology ensures maximum transfer
whatever the load until selected voltage is reached.
■ 5% accuracy all the way up to 1 T-ohm at 5 kV and
2 T-ohm at 10 kV ensures highest accuracy where it
matters most.
■ Date and time-stamped test results reduce the risk of
error in result interpretation.
APPLICATIONS
The units are designed for testing the insulation of high-
voltage electric equipment. Their wide voltage range
also allows applications for low-voltage equipment.
Generators, motors, transformers, cables and switchgear all
require effective maintenance. The test techniques on the
instruments provide valuable diagnostic information.
All three instruments test the insulation resistance of:
n High-voltage power cables and high-voltage buses
n Large motor/generator windings
n Line and substation transformers
The MIT525 and MIT1025 also perform spot tests, step-
voltage tests, dielectric discharge tests, ramp tests, and
dielectric absorption tests for the following applications:
n Acceptance testing at installation to check conformance
to specifications.
n Routine preventive/predictive maintenance testing after
installation.
n QA testing as part of the manufacturing process.
n Diagnostic testing to isolate faulty components for repair.
With its higher voltage testing capability, the MIT1025 is the
perfect everyday work tool for manufacturers, users and
maintainers of rotating machinery. Designed in accordance
with the requirements of IEEE43:2000, the MIT1025 is ideal
for measuring the insulation resistance of armature and
field windings in rotating machines rated 1hp (750 W) or
greater. The standard applies to synchronous, induction
and dc machines as well as synchronous condensers.
FEATURES AND BENEFITS
■■ Smaller size and lighter weight allows easier transport
and use without compromising performance.
■■ High measurement range enables installation testing and
long-term trending of higher value apparatus.
■ Unique dual case design allows for fire-retardant
protection while maintaining ruggedness.
■ High-quality, flexible silicon test leads meet safety
regulations of IEC 61010-31:2008 while ensuring
measurement accuracy.
■ Timed IR plus PI, DAR, DD, SV and ramp tests maximize
diagnostic testing capability.
■ Operate from line power when battery fully discharged
(charges while operating).
■ Two and one-half hour full battery charge time (one-half
hour charge for one hour testing) significantly increases
productivity.
■ Up to six hours continuous testing (5 kV) on a single
battery charge.
n Industry best guard terminal performance to insure
highest accuracy of measured values.
n Enhanced driver technology provides plug-and-play
when connected to the internet. No tedious and
potentially interruptive setup procedures.
■ Dedicated voltmeter function (30 V to 660 V) with
frequency measurement allows the user to check for
induced voltages.
■ CATIV 600 V safety rating on all terminals allows for
safe use in the widest range of applications.
■ Large LCD with automatic backlight.
■ Noise filter rejects up to 3 mA noise for effective
operation in electrically noisy environments.
■ High altitude operation up to 3000 m while maintaining
CATIV 600 V rating.
■ Rotary switch operation for easy, intuitive field use.
■ Field replaceable battery.
MIT515, MIT525, MIT1025
5-kV and 10-kV dc Insulation Resistance Testers
What is the IEEE Standard 43-2000?
In March 2000, the IEEE-SA Standards Board approved
a revision of IEEE Std 43-1974 by the Electric Machinery
Committee of the IEEE Power Engineering Society. This
revision is IEEE Std 43-2000, the “IEEE Recommended
Practice for Testing Insulation Resistance of Rotating
Machinery.” Following is a brief summary of its highlights:
n Test voltages up to 10 kV are recommended for
windings rated greater than 12 kV.
n Both the insulation resistance and the polarization index
test are recommended.
n Test results should be compared to historical values to
identify changes.
n In lieu of historical records, minimum acceptable values
(based on the type of equipment) for both tests are
indicated.
n Depending on the machine rating, the readings for one
or both tests should exceed the minimum acceptable
values.
n If the readings are below the minimum acceptable
values, the winding is not recommended for an over-
voltage test or for operation.