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

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AVTM21-415Ja Rev. A June 2005
energized parts of the test setup must be short-circuited by
means of a safety ground (hot stick). Ground bonds should
then be reapplied.
If the Test Set is operated in accordance with the safety
precautions noted above and in Sections 7and 8,and if all
grounds are correctly made, rubber gloves are not necessary.
As a routine safety procedure, however, some users require
that rubber gloves be worn, not only when making
connections to the high-voltage terminals, but also when
manipulating controls. Megger considers this an excellent
safety practice.
PACEMAKERS
High voltage discharges and other sources of strong electric or
magnetic fields may interfere with the proper functioning of
heart pacemakers. Personnel using heart pacemakers should
obtain expert advice on the possible risks before operating this
equipment or being close to the equipment during operation.
OTHER PRECAUTIONS
§Be especially careful when testing apparatus having high
capacitance such as cables. These items store a dangerous
charge, even at low voltage.
§Identify apparatus terminals and verify apparatus ground, prior
to making connections.
§Do not operate in an explosive atmosphere.
§Read and follow the instruction manual.

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AVTM21-415Ja Rev. A June 2005
3
RECEIVING INSTRUCTIONS
When your instrument arrives, check the equipment received
against the packing list to ensure that all materials are present.
Notify Megger:
Megger
Valley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403 U.S.A.
of any shortage of materials.
Examine the instruments for damage received in transit. If any
damage is discovered, file a claim with the carrier at once and
notify Megger or its nearest authorized sales representative,
giving a detailed description of the damage observed.
This instrument has been thoroughly tested and inspected to
meet rigid inspection specifications before being shipped. It is
ready for use when set up as indicated in Section 7.
A qualified person should become familiar with this entire
Manual and make a test run. This pre-test serves both to
familiarize the user with the Test Set and to check that the set
is operating properly.

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SPECIFICATIONS
POWER SUPPLY: Catalog No. 210415
Voltage (rms): 105-130 Volts
Recommended
Source: NEC 15 Ampere, 120 Volts, single-phase branch circuit (3 wire:line, neutral and
ground).
Current (rms): 1.5 Amps, maximum continuous.
Frequency: 60 Hz, full rating. 50 Hz, reduced rating.
Basis of Rated
Performance: 120 Volt 60 Hz supply with stabilizer out.
OPTIONAL SUPPLY: Catalog No. 210415-47
Voltage (rms): Specify nominal voltage on order.
NOMINAL RANGE
MAXIMUM
CURRENT
210V 208 to 225V 0.80A
230V 225 to 240V 0.83A
250V 240 to 265V 0.85A
Recommended
Source:10-Ampere, nominal voltage, single-phase branch circuit.
Frequency: 60 Hz, full rating;50 Hz, reduced rating
Basis of Rated
Performance: 230 Volt 60 Hz supply with stabilizer out.

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OUTPUT TEST
VOLTAGE: 0-15 kV dc, negative with respect to ground.
OUTPUT CURRENT:
With Stabilizer Out
at 60 Hz: 2 mAcontinuous; 5 mA for 12 minutes.
at 50 Hz: 1.67 mA continuous; 4.17 mA for 12
minutes.
With Stabilizer In at
50 or 60 Hz: At 15 kV, 50 µA continuous.
Short Circuit: 12 mA maximum, limited by circuit breaker.
RIPPLE VOLTAGE
(rms) 1% at 3 MΩresistive load
OUTPUT VOLTAGE
REGULATION:
Internal Stabilizer
Out: 13% no load to 7.5 MΩload
±% percent change in line voltage
Internal Stabilizer In: 0.1% no load to 300 MΩload including
±10% line voltage change
METERING:
Kilovoltmeter: 4½ inch (11.4 cm) Taut-Band.3 color-coded
scales:0-7.5 kV (red), 0-15 kV (black) and 0-
1.5 reference (green). Accuracy: ±2% full
scale.
Megohmmeter: 4½ inch (11.4 cm) Taut-Band.
2 scales: 1-100 Megohms (red), 2-200
Megohms (black). Accuracy: ±2% of full
scale length at any marking, better near high
resistance end.
Ranges: 8 ranges, 4 per scale, as described in
following Table.

SPECIFICATIONS
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AVTM21-415Ja Rev. A June 2005
MEGOHMMETER SPAN, MEGOHMS
VOLTMETER
RANGE
SETTING
VOLTAGE
kV RANGE SWITCH
at x 1
RANGE
SWITCH
at x 10
RANGE
SWITCH
at x 100
RANGE
SWITCH
at x 1K
15 10 2-200 20-2000 200-
20,000 2000- 200,000
7.5 51-100 10-1000 100-
10,000 1000- 100,000
EITHER ANY up to
300 up to 3000 up to 30,000 up to 300,000
CONTROLS
Power OFF-ON switch (Circuit Breaker) with green lamp
indicator.
High Voltage OFF-ON switch (Circuit Breaker) with red lamp
indicator.
Voltage control with Zero-Start interlock, 0-100 reference dial.
Stabilizer selector switch: IN-OUT.
Voltmeter Range Switch: 7.5-15 kV.
Megohmmeter multiplier switch, 4-position: x1, x10, x100,
x1K

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CABLES AND CONNECTORS
Input Cable: Attached; 5 feet (1.5 meters), 3-wire with plug.
Output Cable: Attached; shielded with GUARD terminal, high
voltage clip and boot; 15 feet (4.6 meters) long.
Ground Cable: Separate, 10 feet (3.3 meters) with positive action
clamp at outboard end.
Ground Terminal: ¼inch stud with wing nut.
External
Instrument Jack: Accepts ¼-inch 2-wire phone plug for connecting external recorder or current meter to read current
in test item.
PHYSICAL
Case: High-impact structural foam,
polycarbonate plastic with metal control
panel and removable hinged lid
Size: Overall
Width Depth Height
20 1/8 12 13 inches
52 20.5 33 cm
Weight:
Cat.No. 210415: 35 lbs.(15.9 kg)
Cat. No. 210415-47: 37 lbs.(16.8 kg)
Instruction Card: Permanently attached inside lid.
Cable & Manual Storage: Fits in compartment case.

SPECIFICATIONS
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AVTM21-415Ja Rev. A June 2005
ENVIRONMENT
Temperature: 0°F (-17.7°C) to 122°F (50°C)
maximum operating.
Altitude: 10,000 feet, (3,048 meters)
maximum operating.
Relative Humidity: Non-condensingconditions.
Shock and Vibration: Will withstand normal shock and
vibration encountered in field use
and transportation.
PROTECTIVE FEATURES
§Dual overload protection for all overload conditions by two
separate circuit breakers.
§Metering protected against overload and transient conditions.
SAFETY FEATURES
§"Zero start" interlock: Voltage Control must be at zero to
enable the output voltage circuit to be energized (started).
§Grounded metal control panel.
§Separate visible panel ground cable.
§Permanently attached shielded output cable.
§Separate switches for control power and high voltage output.

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DESCRIPTION
GENERAL
The portable Megohmmeter Test Set measures the electrical
quantities of applied voltage and resistance of the apparatus to
which it is connected. Designed for field or shop use, the
complete Test Set (including all leads) is housed in a rugged
structural foam, polycarbonate case that includes a sturdy
protective lid and carrying strap. For safety in operation, the
control panel of the Test Set is of grounded metal.
ELECTRICAL
The Test Set consists of a variable dc power supply with
metering of the output voltage and current passing between
the high voltage output terminal and ground.
Figure 2 is the schematic diagram of this Test Set.
The high voltage dc power supply is contained within an
internal guard shield. The output of the step-up transformer
T101 supplies a full-wave voltage-doubling rectifier consisting
of protective resistors R107 and R108, the silicon rectifiers
CR101 and CR102 and the output filter capacitors C101 and
C102. For safety the power supply is discharged by the bleeder
resistors R101 and R102. Resistor R104 limits the output
current if the apparatus being tested breaks down. Resistor
R103 is the kilovoltmeter multiplier and capacitor C103
protects the voltmeter from transients. The negative terminal