Megger ATEC 210415 Series User manual

AVTM2
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15Ja
Rev A
June 2005
15 kV Megohmmeter
Test Set
Catalog No. 210415 Series
High-Voltage Equipment
Read the entire manual before operating.
Aparato de Alto Voltaje
Antes de operar este producto lea este manual enteramente.
2621 Van BurenAvenue
Norristown, PA 19403
1-800-723-2861 ext. 8578
megger.com
Advanced Test Equipment Rentals
www.atecorp.com 800-404-ATEC (2832)
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15 kV Megohmmeter Test Set
Catalog No. 210415 Series
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Copyright 1989-2005 by Megger. All rights reserved.
The information presented in this manual is believed to be adequate for
the intended use of the product. If the product or its individual
instruments are used for purposes other than those specified herein,
confirmation of their validity and suitability must be obtained from
Megger. Specifications are subject to change without notice.
MValley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403-2329 USA
Tel: [phone]
Fax: [phone]
www.megger.com

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AVTM21-415Ja Rev. A June 2005
Table of Contents
1 INTRODUCTION.....................................................................................1
2 SAFETY PRECAUTIONS.......................................................................3
3 RECEIVING INSTRUCTIONS.............................................................5
4 SPECIFICATIONS....................................................................................7
5 DESCRIPTION.......................................................................................13
6 CONTROL & CONNECTOR IDENTIFICATION......................17
7 SETTING UP...........................................................................................19
Preparation................................................................................................19
Selection of Location...............................................................................19
Clearances..................................................................................................21
8 OPERATION...........................................................................................27
Test Procedure..........................................................................................27
Breakdown of Test Item.........................................................................28
Normal Shutdown Procedure................................................................29
Interrupting aTest...................................................................................29
9 OPERATION NOTES...........................................................................31
Line Supply................................................................................................31
Meter Range Settings During Transit....................................................31
Megohm Readings....................................................................................31
Correction for Internal Leakage.............................................................33
Stabilizing Switch......................................................................................33
Use of Guard (See Also Section 10)......................................................34
Voltage Control Scale..............................................................................35
Use of Regulation Curve.........................................................................35
Step Voltage Testing................................................................................35
Fault Locating (Breakdown Testing).....................................................36
External Current Meter...........................................................................37

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AVTM21-415Ja Rev. A June 2005
10 APPLICATION NOTES......................................................................41
Theory of Insulation Testing.................................................................41
Applying the Test Set..............................................................................42
Measuring an Ungrounded Test Item...................................................43
Generalized Combined 2 and 3 Terminal Measurement...................45
11 ROUTINE MAINTENANCE............................................................47
Introduction..............................................................................................47
Inspection and Maintenance Procedure...............................................47
12 TROUBLESHOOTING AND REPAIR..........................................51
General......................................................................................................51
Case Repairs..............................................................................................52
Repairs to Components of Chassis and Panel.....................................52
Changing Line Voltage Tap (-47 Models Only)..................................53
Replacement of Output Cable W101....................................................53
Replacement of Power Cord W1...........................................................54
Replacement of Meters or Meter Amplifier Board............................55
Replacement of Megohmmeter Range Circuit....................................55
Replacement of Voltmeter Range Circuit............................................56
Replacement of Stabilizing Switch S1...................................................56
Replacement of Circuit Breakers...........................................................56
Replacement of Voltage Control Autotransformer T1......................57
Replacement of the K2 Assembly.........................................................57
Replacement of Chassis-Mounted Assemblies....................................58
Replacement of Circuit Card U2...........................................................58
Calibration of Voltmeter.........................................................................58
Calibration of Megohmmeter.................................................................59
Adjustment of R1 in Stabilization Network........................................ 61
Trouble Location.....................................................................................63
13 PERFORMANCE CHECK.................................................................69
14 PARTS LIST............................................................................................71
15 WARRANTY AND REPAIRS............................................................73
Warranty....................................................................................................73
Repairs.......................................................................................................73

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AVTM21-415Ja Rev. A June 2005
List of Figures
Figure 1: 15 kV Megohmmeter Test Set, Catalog No. 210415.................2
Figure 2: Schematic Diagram of the 15 kV Megohmmeter....................16
Figure 3A: View of the 15 kV Megohmmeter Test Set...........................17
Figure 3B: View of the 15 kV Megohmmeter Test Set...........................18
Figure 4: Testing in a Substation.................................................................23
Figure 5: Testing Parking Lot Lighting......................................................24
Figure 6: Testing Transformer Terminals.................................................25
Figure 7: DC Motor Test Setup..................................................................26
Figure 8: Generator Test Setup...................................................................26
Figure 9: Regulation Curves with Stabilizer "OUT", 120V Supply.......37
Figure 10: Typical Guard Connection to Cable Pothead........................38
Figure 11: Guard Connection for a Typical Cable Test..........................38
Figure 12: Typical Guard Connection for an Oil Circuit Breaker.........39
Figure 13: Typical Guard Connection for Transformer Test................ 39
Figure 14: Two-winding Transformer in Three-Terminal Form...........44
Figure 15A: Interior View............................................................................66
Figure 15B: Interior View............................................................................66
Figure 16: Connections for Calibration of Voltmeter.............................67
Figure 17: Connections for Calibration of the Megohmmeter..............67

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AVTM21-415Ja Rev. A June 2005
List of Tables
TABLE 1: Minimum Air Clearances..........................................................21
TABLE 2: Two & Three Terminal Measurement
Connection Schedule................................................................44
TABLE 3: Trouble Location Chart............................................................63

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AVTM21-415Ja Rev. A June 2005
1
INTRODUCTION
This Instruction Manual is intended as a guide to the operation
and maintenance of the portable 15 kV Megohmmeter Test
Set, Catalog No. 210415 for use on 120 Volt supply and
Catalog No. 210415-47 used when supply is between 200 and
250 Volts. References in this manual to optional functions and
equipment may be disregarded when such information does
not apply to the Test Set in use. The options included in the
set for which this manual is supplied are indicated in nameplate
data.
The instructions and suggestions provided in this manual
anticipate the normal use of the Megohmmeter Test Set for
testing electrical insulation systems on such equipment as
motors, generators, bushings, and cables. These tests, which
are based on measurement of the applied dc voltage, the
equivalent resistance, and the manner in which resistance varies
with time, provide data that indicate the condition of the
insulation system of the apparatus being tested. When these
data are recorded on graph paper such as Megger Ki1ovo1t-
Megohm Paper (Catalog No. 220000), the shape of the curve
made by connecting the plotted points will aid in evaluating the
condition of the insulation system. Information on the
interpretation of observed data and guides for testing are given
in Section 10.

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AVTM21-415Ja Rev. A June 2005
Figure 1: 15 kV Megohmmeter Test Set,
Catalog No. 210415

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AVTM21-415Ja Rev. A June 2005
2
SAFETY PRECAUTIONS
SAFETY ISTHE RESPONSIBILITY OF THE USER.
LA SEGURIDAD ES LA RESPONSABILIDAD DEL OPERADOR.
The Test Set and the equipment to which it is connected are a
source of high-voltage electrical energy. All persons
performing or assisting in the tests must use all practical safety
precautions to prevent contact with energized parts of the test
equipment and associated circuits. Persons actually engaged in
the test must stand clear of all parts of the complete high-
voltage circuit unless the Test Set is de-energized and all parts
of the test circuit are grounded.Persons not directly associated
with the work must be kept away from test activities by
suitable barriers, barricades or warnings.
The Test Set panel must be connected to a reliable local
ground to prevent possible shock danger to the operator. Since
the energized test setup may induce a static voltage charge on
nearby insulated objects, including people, all insulated objects
must be grounded or kept at least two feet (61 cm) from the
energized structure.
All apparatus to be tested must be de-energized and should be
bonded to ground except during the actual test. Note that even
isolated conductors may develop static voltage with respect to ground due to
nearby electric fields, wind friction or passing electrified clouds. Test
connections should be made with the ground bonds in place.
At the completion of a test, after the power source has been
shut down and the Test Set kilovoltmeter reads zero, all