Resonating Inductor User Guide
Resonating Inductor User Guide
Rev. B
December 2002
High-Voltage Equipment
Read the entire manual before operating.
PO Box 9007
Valley Forge, PA 19485-1007 U.S.A.
610-676-8500
Shipping Address:
Valley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403 U.S.A.
Resonating Inductor
Instruction Manual
1 Introduction ................................................................................................................... 1
Receiving Instructions ....................................................................................................................... 1
General Information.......................................................................................................................... 1
2 Safety.............................................................................................................................. 3
3 Specifications................................................................................................................. 5
Electrical .............................................................................................................................................. 5
Physical Characteristics ..................................................................................................................... 5
Environmental Conditions ............................................................................................................... 6
Noise .................................................................................................................................................... 6
Accessories Supplied.......................................................................................................................... 6
5 Use of the Resonating Inductor with the DELTA-2000 10-kV Automated Insulation
Test Set (Cat. No. 672001) .......................................................................................... 13
Setup................................................................................................................................................... 13
Operation .......................................................................................................................................... 15
6 Service .......................................................................................................................... 17
Periodic Maintenance ...................................................................................................................... 17
Repair ................................................................................................................................................. 17
Glossary ............................................................................................................................ 21
Warranty ........................................................................................................................... 23
List of Illustrations
Introduction
Receiving Instructions
Check the equipment received against the packing list to ensure that all materials are
present. Notify Megger of any shortage. Telephone 1-800-723-2861 or 610-676-8578
and ask for the Customer Service Department.
Examine the equipment for damage received in transit. If damage is discovered, file a
claim with the carrier at once and notify Megger, giving a detailed description of the
damage.
The Resonating Inductor has been thoroughly tested and inspected to meet rigid
specifications before being shipped. It is ready for use when set up as indicated in this
manual.
General Information
The Resonating Inductor (Fig. 1) is an accessory for use with the Extended-Range
Capacitance and Dissipation Factor Test Set (Cat. No. 670070) and the DELTA-2000
10-kV Automated Insulation Test Set (Cat. No. 672001). The Resonating Inductor is
connected in parallel with the internal power supply of the test set and will extend its
capability to test larger test samples, particularly for the motor, generator, and cable test
market. The use of the Resonating Inductor extends the short time rating of the power
supply of the test set from 200 mA to 3.77 A. This capacity is suitable for testing
capacitance loads up to 1 µF at 10 kV. A manual tuning wheel varies the inductance to
tune the parallel circuit for minimum load current.
Safety
The Resonating Inductor, the test set, and the specimen to which it is connected are a
source of high-voltage electrical energy and all persons making or assisting in tests must
use all practical safety precautions to prevent contact with energized parts of the test
equipment and related circuits. Persons actually engaged in the test must stand clear of
all parts of the complete high-voltage circuit, including all connections, unless the test
set is de-energized and all parts of the test circuit are grounded. Persons not directly
involved with the work must be kept away from test activities by suitable barriers,
barricades, or warnings. An interlock circuit is provided on the control unit of the test
set to enable the operator to enclose all parts of the complete high-voltage circuit within
a secure area. The interlock circuit should be used to shut off input power automatically
upon unauthorized entry into the high-voltage area.
Treat all terminals of high-voltage power equipment as a potential electric shock hazard.
There is always the potential of voltage being induced at these terminals because of
proximity to energized high-voltage lines or equipment. Always use a safety ground stick
to ground the high-voltage conductor. A safety ground jumper must then be installed
between the terminals of the specimen under test and ground. Always disconnect test
leads from power equipment before attempting to disconnect them at the test set. The
ground connection must be the first made and the last removed. Any interruption of the
grounding connection can create an electric shock hazard.
Megger has made formal safety reviews of the initial design and any subsequent
changes. This procedure is followed for all new products and covers areas in addition to
those included in applicable ANSI standards. Regardless of these efforts, it is not
possible to eliminate all hazards from electrical test equipment. For this reason, every
effort has been made to point out in this instruction manual the proper procedures and
precautions to be followed by the user in operating the tester and to mark the tester
itself with precautionary warnings where appropriate. However, it is not possible to
foresee every hazard which may occur in various applications of this tester. It is
therefore essential that the USER, in addition to following the safety rules in this
manual, also carefully consider all safety aspects of the test before proceeding.
If the test equipment is operated properly and all grounds correctly made, test personnel
need not wear rubber gloves. 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 the controls. Megger considers this an
excellent safety practice.
Specifications
Electrical
Voltage rating: 10 kV ac
Current rating: 3.77 A at 50/60 Hz
15 minutes on, 2 hours off
Maximum capacitive load: 1 µF @ 60 Hz, 1.2 µF @ 50 Hz
Note: At maximum capacitive load, test set may reach its maximum output current rating at less than
full output voltage depending on dissipation factor of specimen.
Minimum capacitive load: 0.05 µF, 50 or 60 Hz
Tuning: By manual tuning wheel
Test modes: UST (ungrounded specimen test) and GST (grounded
specimen test); in both these test configurations, the
Resonating Inductor does not affect the accuracy
specification of the test set.
Physical Characteristics
Noise
Accessories Supplied
Setup
WARNING
Testing high-voltage power equipment can be dangerous if improperly
performed. Read and understand all safety information in this
instruction manual as well as the instruction manual for the test set.
Ensure test specimen is de-energized, grounded, and safety ground
jumpers have been applied before making connections. Read and
understand all details of setup and operation in both instruction
manuals.
The following steps are a general guide for setting up the Resonating Inductor for use
with the Extended Range Capacitance and Dissipation Factor Test Set
(Cat. No. 670070). Figure 2 shows the setup for testing ungrounded capacitance
specimens; Figure 3 shows the setup for grounded capacitance specimens.
1. Locate the test set and Resonating Inductor on a sturdy level surface at least 6 ft
(1.8 m) from the specimen to be tested.
2. Connect the wing thumb-nut ground terminal of the test set to a low-impedance
earth ground using the 15 ft (4.6 m) ground lead supplied.
4. Connect the test set control unit interconnection receptacles to the corresponding
high-voltage unit receptacles using the two 5 ft (1.52 m) interconnecting cables
(supplied with the test set). Make sure the bayonet type plugs are fully locked on the
receptacles.
5. If making a UST test, connect the low-voltage lead with red colored boot to the
CxL RED receptacle of the test set. Make sure the connector locks to the
receptacle.
8. Using the 8 ft (2.4 m) high-voltage lead, connect the end with pigtail lead to the HV
receptacle on the high-voltage unit of the test set. Connect the pigtail lead to the
black binding post adjacent to the HV receptacle. Connect the other end of the
high-voltage lead to the high-voltage receptacle on the Resonating Inductor labeled
HIGH VOLTAGE IN. Insert the plug shells fully into the receptacles.
9. Connect the 70 ft (21.4 m) high-voltage cable (supplied with the test set) to the
high-voltage terminal of Resonating Inductor labeled HIGH VOLTAGE OUT.
Insert the plug shell fully into the receptacle. Connect the pigtail lead of this cable to
the wing thumb-nut ground terminal.
Note: The crocodile clip for the high-voltage lead should be used instead of the hook assembly since test
current levels will be considerably higher than use of the test set without Resonating Inductor.
10. If making a UST test, connect the crocodile clip of the low-voltage lead to the
low-voltage terminal of the test specimen.
11. Connect the crocodile clip of the high-voltage lead to the desired high-voltage
terminal of the test specimen.
12. With the test set main breaker OFF, plug the input power cord into the test set
power receptacle and into a three-wire grounded power receptacle having the
appropriate voltage and current ratings.
Operation
Proceed only after fully understanding Section 2, Safety, and setting up the test set and
Resonating Inductor as described. The following instructions are the normal procedures
for conducting a test.
2. Remove all safety ground jumpers from the specimen terminals (not housing).
CAUTION
Observe the following precautions (different from normal test set
operating procedures) to prevent damage to the test set:
Do not change the setting of the UST/GST test mode switch while
testing.
Use only normal voltage polarity when making measurements.
Do not change the setting of the capacitance and dissipation
factor interference suppressor controls from OFF.
When initially energizing the test specimen, always set the
capacitance multiplier dial to SHORT and the measuring dials to
“0.” This will prevent possible damage to the test set in the
event of a specimen breakdown.
4. Check for proper selection of the mode of operation on the UST/GST selector
switch.
6. Set the HV ON/OFF switch to ON. The red lamp should light when the
VOLTAGE CONTROL is set to “0.”
7. Advance the VOLTAGE CONTROL gradually while observing both the test
voltage and the test current. The initial voltage level should not exceed 20 percent of
the desired test voltage and the initial current level should not exceed 50 mA.
Note: Circuit breaker trip-out will occur if the current level exceeds 200 mA.
8. Using the manual tuning wheel on the Resonating Inductor, tune for a minimum
current reading. The graph of Figure 4 shows the approximate gap opening versus a
tuned load.
10. Adjust the "C" multiplier dial and the "C" measuring dials in the normal way to
bring the null indicator to zero. The first "C" measuring dial should have at least
one step in circuit for full accuracy.
CAUTION
Use only the 1K, 2K and 10K capacitance multiplier ranges to prevent
overcurrent damage to the bridge circuit windings. Always initially
balance the bridge on the highest capacitance multiplier range.
Once balanced, a lower multiplier of 1K or 2K may be selected if
appropriate. The following is the final capacitance multiplier range
for capacitance measurements.
Capacitance Multiplier Capacitance Value
10K 0.2 to 1.1µF
2K 0.1 to 0.2 µF
1K 0.04 to 0.1 µF
11. Read the capacitance value from the sum of “C” dial settings multiplied by the
setting of the “C” multiplier dial.
12. Read the % DF value from the digital panel meter. Note the sign of reading (+ or -).
Note: Watt readings are direct readings of equivalent 10 kV watt values. However, when using the 10
K capacitance multiplier, the reading must be multiplied by a factor of 10 to obtain the correct watt
value. The % DF value is a direct reading on all capacitance multiplier ranges.
13. When the tests have been completed, gradually reduce the test voltage to zero,
switch the HV ON/OFF switch to OFF, then switch the main breaker to OFF.
14. Set the Capacitance Multiplier dial to SHORT and the Capacitance Measuring dials
to their respective “0” positions.
15. Discharge the specimen with a safety ground stick, then apply safety ground
jumpers to the specimen terminals while the safety ground stick is still in place.
17. Disconnect the leads from the test set and the Resonating Inductor. The ground
leads should be disconnected last.
Setup
WARNING
Testing high-voltage power equipment can be dangerous if improperly
performed. Read and understand all safety information in this
instruction manual as well as the instruction manual for the test set.
Ensure test specimen is de-energized, grounded, and safety ground
jumpers have been applied before making connections. Read and
understand all details of setup and operation in both instruction
manuals.
The following steps are a general guide for setting up the Resonating Inductor for use
with the DELTA-2000 Test Set (Cat. No. 672001). Figure 5 shows the setup for testing
ungrounded capacitance specimens; Figure 6 shows the setup for grounded capacitance
specimens.
1. Locate the test set and the Resonating Inductor on a sturdy level surface at least 6 ft
(1.8 m) from the specimen to be tested.
2. Connect the wing thumb-nut ground terminal of the test set to a low-impedance
earth ground using the 15 ft (4.6 m) ground lead supplied.
3. Connect the wing thumb-nut ground terminal of the Resonating Inductor to a low-
impedance earth ground using the 15 ft (4.6 m) ground lead supplied.
4. Connect the test set control unit interconnection receptacles to the corresponding
high-voltage unit receptacles using the two 5 ft (1.52 m) interconnecting cables
(supplied with the test set). Make sure the bayonet type plugs are fully locked on the
receptacles.
5. If making a UST (MEASURES RED, GROUNDS BLUE) test, connect the low-
voltage lead to the LOW VOLTAGE RED receptacle of the test set. Make sure that
the connector locks to the receptacle.
6. Connect the external interlock cables to the INTERLOCK receptacles of the test
set. Make sure the bayonet type plugs are fully locked on the receptacle.
8. Using the 8 ft (2.4 m) high-voltage lead, connect the end with pigtail lead to the HV
receptacle on the high-voltage unit of the test set. Connect the pigtail lead to the
thumb nut ground terminal adjacent to the HV receptacle. Connect the other high-
voltage connector of the cable to the high-voltage receptacle on the Resonating
Inductor labeled HIGH VOLTAGE IN. Insert the plug connectors fully into the
receptacles.
9. Connect the 70 ft (21.4 m) high-voltage cable (supplied with the test set) to the
high-voltage terminal of the Resonating Inductor labeled HIGH VOLTAGE OUT.
Insert the plug connector fully into the receptacle. Connect the pigtail lead of this
cable to the wing thumb-nut ground terminal.
Note: The crocodile clip for the high-voltage lead should be used instead of the hook assembly since test
current levels will be considerably higher than use of the test set without Resonating Inductor.
10. If making a UST (MEASURES RED, GROUNDS BLUE) test, connect the
crocodile clip of the low-voltage lead to the low-voltage terminal of the test
specimen.
11. Connect the crocodile clip of the high-voltage lead to the desired high-voltage
terminal of the test specimen.
12. With the test set main breaker OFF, plug the input power cord into the test set
power receptacle and into a three-wire grounded power receptacle having the
appropriate voltage and current ratings.
Operation
Proceed only after fully understanding Section 2, Safety, and setting up the test set and
Resonating Inductor as described. The following instructions are the normal procedures
for conducting a test.
1. Remove all safety ground jumpers from the specimen terminals (not housing).
3. See Figures 19 and 20 in the DELTA-2000 Instruction Manual AVTM 672001 for
sample test screens.
6. Press the HIGH VOLTAGE ON button. The red lamp should light when the
HIGH VOLTAGE CONTROL is set to “0.”
7. Advance the HIGH VOLTAGE CONTROL gradually while observing both the
test voltage and test current. The initial voltage level should not exceed 20 percent
of the desired test voltage and the initial current level should not exceed 50 mA.
Note: Circuit breaker trip-out will occur if the current level exceeds 200 mA.
8. Using the manual tuning wheel on the Resonating Inductor, tune for a minimum
current reading. The graph of Figure 4 shows the approximate gap opening versus a
tuned load.
EMERGENCY SHUTDOWN
Press the HIGH VOLTAGE OFF button, open any of the external
interlocks, or switch main breaker OFF.
11. When the measurement is completed, observe the test results on the LCD screen.
Readings may be printed out or stored as desired.
12. When the tests have been completed, gradually reduce the test voltage to zero and
press the HIGH VOLTAGE OFF button.
13. Discharge the specimen with a safety ground stick, then apply safety ground
jumpers to the specimen terminals while the safety ground stick is still in place.
15. Disconnect the leads from the test set and the Resonating Inductor. The ground
leads should be disconnected last.
Service
Periodic Maintenance
Maintenance should be performed only by qualified persons familiar with the hazards
involved with high-voltage test equipment. Read and understand Section 2, Safety,
before performing any service. To maintain the Resonating Inductor in maximum
operating condition, perform the following periodic maintenance:
After every 50 hours of operation, grease the fitting situated under the tuning wheel
using a petroleum oil base grease with lithium thickening agent. The grease should be of
medium soft consistency (NLGI No. 2) with a temperature rating of -10 to 250°F.
Annually, remove panel above wheels, being careful not to damage guard wire
connection to panel shield. Disconnect guard wire connection by unscrewing retaining
nut. Set the panel aside. Using an air compressor, blow out the inside to remove
accumulated dirt, dust and debris. Reconnect guard wire to panel shield and reinstall
panel.
Periodically, check all nuts and bolts to ensure that they are properly secured. Tighten as
necessary.
Repair
Megger offers a complete repair service and recommends that its customers take
advantage of this service in the event of any equipment malfunction. Please indicate all
pertinent information including problem symptoms and attempted repairs. The catalog
number and serial number of the equipment should be specified. Equipment returned
to the factory for repair must be shipped prepaid and insured and marked for the
attention of the Repair Department.
V High-voltage warning.