Omicron CP SB1 User manual

CP SB1
TRANSFORMER SWITCH BOX
FOR MEASURING RATIO AND
WINDING RESISTANCE AND
TESTING THE TAP CHANGER
OF POWER TRANSFORMERS
User Manual

CP SB1 User Manual
2
Manual Version: CPSB1.AE.1
© OMICRON electronics 2009. All rights reserved.
This manual is a publication of OMICRON electronics GmbH.
All rights including translation reserved. Reproduction of any kind, for example, photocopying,
microfilming, optical character recognition and/or storage in electronic data processing systems,
requires the explicit consent of OMICRON electronics. Reprinting, wholly or in part, is not permitted.
The product information, specifications, and technical data embodied in this manual represent the
technical status at the time of writing and are subject to change without prior notice.
We have done our best to ensure that the information given in this manual is useful, accurate and
entirely reliable. However, OMICRON electronics does not assume responsibility for any inaccuracies
which may be present.
The user is responsible for every application that makes use of an OMICRON product.
OMICRON electronics translates this manual from the source language English into a number of other
languages. Any translation of this manual is done for local requirements, and in the event of a dispute
between the English and a non-English version, the English version of this manual shall govern.

3
Contents
Contents
Using This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Operator Qualifications and Safety Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Conventions and Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Related Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Safety Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Operating the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
DC Output to Test Objects with a High Inductance . . . . . . . . . . . . . . . . . . . . . . . 9
High-Voltage Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Static Charges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Orderly Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1 Hardware Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.2 Circuit Diagram of the CP SB1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.3 Functional Components of the CP SB1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.4 CP SB1 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
2.1 Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 Operating Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.3 Test Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
3.1 Safety Instructions for Connecting the CP SB1 to Power Transformers . . . . . . 21
3.1.1 Before Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1.2 Connecting the Measurement Setup to Power Transformers . . . . . . . . . . . . 21
3.2 Template Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3 Test Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4 TRRatio Test Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.4.1 Test Settings for TRRatio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.4.2 Performing Measurements with TRRatio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4.3 Trouble-Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.5 TRTapCheck Test Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.5.1 Test Settings for the Winding Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.5.2 Performing Winding Resistance Measurements . . . . . . . . . . . . . . . . . . . . . . 49
3.5.3 Trouble-Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

CP SB1 User Manual
4
4 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.1 Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.2 Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.2.1 Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.2.2 Shock and Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.3 Mechanical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.4 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.2.5 Safety Standards, Electromagnetic Compatibility (EMC). . . . . . . . . . . . . . . . 55
5 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.1 Transformer Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.1.2 Fault Localization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.1.3 Winding Resistance Measurement and On-Load Tap Changer Test. . . . . . . 59
5.1.4 Four-Wire Connection for Transformer Winding Resistance Measurement. . 63
5.1.5 Safety Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.1.6 Delta-Connected Windings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.1.7 Winding Resistance Measurement of a 100 MVA Transformer . . . . . . . . . . . 65
5.1.8 Dynamic Behavior of the Diverter Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.1.9 Turns Ratio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.2 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Contact Information / Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

5
Using This Manual
Using This Manual
This User Manual provides detailed information on how to use the CP SB1
transformer switch box safely, properly and efficiently. The CP SB1 User Manual
contains important safety instructions for working with the CP SB1, gets you
familiar with operating the CP SB1, and provides typical application examples.
Following the instructions in this User Manual will help you to prevent danger,
repair costs and possible down time due to incorrect operation.
The CP SB1 User Manual always has to be available at the site where the
CP SB1 is used. It must be read and observed by all users of the CP SB1.
Reading the CP SB1 User Manual alone does not release you from the duty of
complying with all national and international safety regulations relevant to
working with the CPC 100 and CP SB1. The regulation EN 50191 "The Erection
and Operation of Electrical Test Equipment" as well as all the applicable
regulations for accident prevention in the country and at the site of operation has
to be fulfilled.
Operator Qualifications and Safety Standards
Working on overhead lines is extremely dangerous. Testing and measuring with
the CP SB1 must be carried out only by qualified, skilled and authorized
personnel. Before starting to work, clearly establish the responsibilities.
Personnel receiving training, instructions, directions, or education on the
CP SB1 must be under constant supervision of an experienced operator while
working with the equipment.
Testing and measuring with the CP SB1 must comply with the relevant national
and international safety standards listed below:
• EN 50191 (VDE 0104) "Erection and Operation of Electrical Equipment"
• EN 50110-1 (VDE 0105 Part 100) "Operation of Electrical Installations"
• IEEE 510 "IEEE Recommended Practices for Safety in High-Voltage and
High-Power Testing"
Moreover, additional relevant laws and internal safety standards have to be
followed.

CP SB1 User Manual
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Conventions and Symbols Used
In this manual, the following symbols indicate paragraphs with special safety
relevant meaning:
Related Documents
The following documents complete the information covered in the CP SB1 User
Manual:
Symbol Description
Equipment damage or loss of data
possible.
Personal injury or severe damage to
objects possible.
Title Description
CPC 100 User Manual Contains information on how to use
the CPC 100 test system and
relevant safety instructions.
CPC 100 Reference Manual Contains detailed hardware and
software information on the CPC 100
including relevant safety instructions.

7
Safety Rules
Safety Rules
Before operating the CP SB1 transformer switch box, read the following safety
rules carefully. If you do not understand some safety rules, contact OMICRON
electronics before proceeding. The CP SB1 is designated for use with the
CPC 100 test system. Therefore, observe the safety rules both in this User
Manual and in the CPC 100 User/Reference Manual when working with the
CP SB1.
Depending on the application and the device under test, specific safety
instructions must be observed. Very often, the danger coming from the device
under test is even higher than the danger from the CP SB1 itself. For
application-specific safety instructions, see 3.1 "Safety Instructions for
Connecting the CP SB1 to Power Transformers" on page 21.
Maintenance and repair is only permitted by qualified experts either at the
factory or certifeid external repair centers.
General
Always observe the five safety rules:
• Disconnect completely
• Secure against re-connection
• Verify that the installation is dead
• Carry out grounding and short-circuiting
• Provide protection against adjacent live parts
Operating the Measurement Setup
Only personnel qualified in electrical engineering and trained by OMICRON
electronics are authorized to operate the CP SB1. Before starting the work,
clearly establish the responsibilities.
Personnel receiving training, instructions, directions, or education on the
CPC 100 or CP SB1 must be under constant supervision of an experienced
operator while working with the equipment.
The operator is responsible for the safety requirements during the whole test.

CP SB1 User Manual
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In principle, the safety instructions that apply to the CPC 100 and its accessories
(refer to "Safety Instructions for CPC 100 and its Accessories" in the CPC 100
Reference Manual) also apply to the CP SB1. Following, only safety instructions
that exclusively apply to the CP SB1 are listed. Before performing tests using
high voltage, please read the following:
• Do not use the test equipment without a good connection to substation
ground.
• Keep clear from zones in which high voltages may occur. Set up a barrier or
establish similar adequate means.
• Make sure to position the CP SB1 in a safe area.
• Pay attention to the national and the international standards for the safe
operation of high-voltage test equipment (EN 50191, IEEE 510).
• Never touch any terminal without a visible ground connection!
• Before connecting or disconnecting test objects and/or cables, turn off the
CPC 100 by either the POWER ON/OFF switch or the Emergency Stop
button. Never connect or disconnect a test object while the outputs are
active.
Note: Even if you switched off the CPC 100, wait until the red I/O warning
light is fully extinguished. As long as this warning light is lit, there is still
voltage and/or current potential on one or more of the outputs.
• Make sure that the test object's terminals that are to be connected to the
CP SB1 or CPC 100 do not carry any voltage potential. During a test, the only
power source for a test object may be the CPC 100.
• Do not insert objects (for example screwdrivers, etc.) into any input/output
socket.
• When measuring the ratio of power transformers make sure that the test
voltage is connected to the corresponding high-voltage winding, and the
voltage of the low-voltage winding is the one that is measured. Accidentally
mixing up the windings can generate life-threatening voltages within the
transformer.

9
Safety Rules
For example: feeding a voltage of 300 V to the low-voltage winding of a
power transformer that has a ratio of 400000 V : 30000 V, induces a voltage
of 4000 V in the transformer's primary winding.
• Do not operate the CP SB1 under ambient conditions that exceed the
temperature and humidity limits listed in 4 "Technical Data" on page 53.
• Make sure to position the test equipment on dry, solid ground.
• Do not operate the CP SB1 in the presence of explosives, gas or vapors.
• Opening the CP SB1 invalidates all warranty claims.
•IftheCP SB1 or any add-on device or accessory does not seem to function
properly, do not use it anymore. Please call the OMICRON electronics
hotline.
• Before handling the CP SB1 or CPC 100 in any way, connect them with a
solid connection of at least 6 mm2cross-section to equipotential ground.
Ground the CP SB1 as close as possible to the CPC 100.
DC Output to Test Objects with a High
Inductance
When using the DC Output to test power transformers with a high inductance,
observe the following safety instructions:
•UsetheTRTapCheck (tap changer winding resistance and on-load tap
changer interruption check) test card only.
• As long as the CPC 100 software shows the on-screen message "Switch off
in progress", NEVER connect or disconnect test objects and/or cables.
• The message "Switch off in progress" notifies you that, while the CPC 100 is
deactivating, the connected external inductance (this means the test object)
still "feeds" voltage potential back into the 6 A DC output.
Note: The existence of this voltage potential at the 6 A DC output is also
indicated by a lit LED - even if the CPC 100 is switched off.
• If a test object with a high inductance was connected to the CPC 100, short-
out the test object additionally before disconnecting any cables.
High-Voltage Outputs
All AC and DC output sockets of the CP SB1 can carry life-hazardous voltage
potential and provide life-hazardous currents. Therefore:
• While connecting cables to the CP SB1 outputs or other conducting parts
that are not protected against accidental contact, press the Emergency Stop

CP SB1 User Manual
10
button on the CPC 100 front panel, and keep it pressed as long as an output
signal is not absolutely necessary for the test.
• When connecting cables to the front panel input/output sockets, use wires
with 4 mm safety "banana" connectors and plastic housing.
• For the connection between the CPC 100 and CP SB1 only use the specially
manufactured cables supplied by OMICRON electronics (see 1.4 "CP SB1
Accessories" on page 17).
Note: One end of the high-voltage cable has a coaxial safety plug that is
certified for a voltage level of 2 kV AC. The other end is equipped with a
safety banana plug that is insulated with a shrink tube.
• When the CPC 100 is activated, consider this part of the cable to be a hazard
of electric shock.
• Do not stand right next to or directly underneath a connection point because
the clamps may fall off and touch you. This is a physical and an electrical
hazard.
• The red warning light on the CPC 100 front panel indicates hazardous
voltage and/or current levels at the CPC 100 outputs (red light "I" on or
flashing). The green warning light indicates that the CPC 100 outputs are not
activated.
Note: If none or both warning lights are on, the unit is defective and must not
be used anymore.
Static Charges
Static charges on transformer windings may be induced by test potentials. While
the voltage may not be significant enough to cause any damage, it can be a
source for serious accidents due to falls caused by reflex action.
Connect the windings to ground as described in the CPC 100 Reference
Manual.
Orderly Measures
The CP SB1 User Manual or alternatively the e-book in PDF format has always
to be available on site where the CP SB1 is being used. It must be read and
observed by all users of the CP SB1.
The CP SB1 may be used only as described in 3 "Application" on page 21. Any
other use is not in accordance with the regulations. The manufacturer and/or
distributor is not liable for damage resulting from improper usage. The user
alone assumes all responsibility and risk.

11
Safety Rules
Following the instructions provided in this User Manual is also considered part
of being in accordance with the regulations.
Disclaimer
If the equipment is used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired.

CP SB1 User Manual
12

13
Hardware Information
1 Hardware Information
1.1 Overview
The CP SB1 is a transformer switch box designated for automatically measuring
the ratio and winding resistance, and testing the tap changer of three-phase
power transformers. It is an accessory to the CPC 100. Automatic control of the
On-Load Tap Changer (OLTC) is included. Testing of power transformers over
all taps and all phases is fully automated. Therefore, no rewiring is required. The
CP SB1 is controlled from the CPC 100 via its serial interface. The results are
recorded in the CPC 100 with the ratio and tap changer test cards, and can be
analyzed with the computer tool set (CPC 100 Excel File Loader).

CP SB1 User Manual
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1.2 Circuit Diagram of the CP SB1
Figure 1-1 Circuit diagram of the CP SB1
AC / DC Input V1 AC / V DC
Output
Serial
Equipo-
tential
ground
terminal
Beeper
Control unit
Overcurrent protection
To Tap Changer
To Transformer
Power Relays
Matrix
Measurement
Relays Matrix
Up Down
To Transformer
High
Voltage
Low
Voltage
Surge arrestor
Source (S)
High
Voltage
Low
Voltage
Measure (M)
Discharge
circuit

15
Hardware Information
1.3 Functional Components of the CP SB1
The front panel of the CP SB1 provides the following functional components:
• Transformer High Voltage:
– Outputs (Source) for the input of current or voltage on the individual
phases of the transformer
– Inputs (Measure) for the voltage measurement
Note: The inputs and outputs of the respective connections (U/H1, V/H2,
W/H3, N/H0) are connected to the transformer using Kelvin clamps.
• Transformer Low Voltage:
– Outputs (Source) for the input of current or voltage on the individual
phases of the transformer
– Inputs (Measure) for the voltage measurement
Note: The inputs and outputs of the respective connections (u/X1, v/x2,
w/x3, n/X0) are connected to the transformer using Kelvin clamps.
• Tap Changer: Two potential-free contacts for switching the tap changer
• AC input for connection to the 2 KV AC output of the CPC 100
• DC input for connection to the 6 A DC output and I AC/DC input of the
CPC 100
• AC output for connection to the V1 AC input of the CPC 100
• DC output for connection to the V DC input of the CPC 100
• Serial interface for the CPC 100 (TRRatio and TRTapCheck test cards) to
control the CP SB1
• Equipotential ground terminal for grounding the CP SB1 close to the position
of the operating staff

CP SB1 User Manual
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Figure 1-2 Front panel
AC Input DC Input V1 AC Output V DC Output Serial
connection
Transformer High
Voltage
Tap Changer
Up Down
Equipotential
ground
terminal
Transformer Low
Voltage
LEDs
Read the
manual

17
Hardware Information
1.4 CP SB1 Accessories
The following accesories are delivered with the CP SB1 tranformer switch box:
Table 1-1 CP SB1 Accessories
Accessories Description
1x Transport case To transport the entire
equipment
Coax. cables
15 m/2.5 mm2
3x red, 3x blue, 2x
green, 2x yellow
supplied in cable drums
Connection from the
CP SB1 to the
transformer via Kelvin
clamps and the tap
changer via flexible
terminal adapter
1x Grounding cable Connection from the
CP SB1’s equipotential
ground terminal to the
substation ground
Banana cables
2m
4x red and 4x black
Connection from the
CPC 100 to the
CP SB1’s DC input, V1
AC output and V DC
output

CP SB1 User Manual
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8 Kelvin clamps
black
Connection to bushings
6x Flexible terminal
adapter
Connection to tap
changer
1x Data cable
3m
grey
Connection from the
CP SB1 to the CPC 100
1x Backpack To transport the cable
drums and Kelvin
clamps
Table 1-1 CP SB1 Accessories (continued)
Accessories Description

19
Operation
2 Operation
2.1 Measurement Setup
The measurement setup consists of the CPC 100 test system and the CP SB1
transformer switch box. Figure 2-1 "Measurement setup" shows the functional
setup.
Figure 2-1 Measurement setup

CP SB1 User Manual
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2.2 Operating Principle
The CP SB1 is a transformer switch box whose relays are controlled by the
serial interface of the CPC 100 test system. Potential-free relay contacts control
the AC tap changer of the transformer under test. With the switch box, you can
measure the winding resistance (current up to 6 A) and ratio on three-phase
transformers (output voltage limited to 300 V/150 V). Automatic control of the
OLTC is included. The CP SB1 consists of a relay switching matrix with which
you can conduct automatic testing.
An integrated logic which is controlled by the CPC 100 controls the relays and
the OLTC. The CP SB1 has two outputs to operate the tap changer together with
an optimized "Auto Keep Result" algorithm within the TRTapCheck test card.
Both TRRatio and TRTapCheck test cards can record the results of all three
phases with a single test card. The switch box automatically switches to the next
phase after testing of a phase is completed.
You can conduct the transformer ratio test and the time-consuming tap changer
resistance test over all taps and all three phases without rewiring. For special
measurements and single-phase transformers, the operation mode can be set
to manual. In this case, use banana cables between the connections to the
transformer and the CPC 100 of the CP SB1.
An acoustic signal (intermittent beep) indicates if the discharge is in progress. A
double beep informs the user when a correct connection has been established.
An intermittent beep with a longer interval sounds in case of firmware download.
For the ratio measurement, the voltage is always injected into the high-voltage
side of the transformer. The winding resistance can be measured on the high-
or low-voltage side. Manual mode is possible for both TRTapCheck and
TRRatio.
Note: For detailed information about the ratio measurement, as well as winding
resistance and tap changer test, refer to the CPC 100 User Manual.
2.3 Test Cards
The CP SB1 comprises two test cards: TRRatio to measure the ratio, and
TRTapCheck to test the tap changer of power transformers and the winding
resistance.
Note: The license is indicated on the nameplate with the option "advanced". If
your CP SB1 has a license, the tap check runs in automatic mode by default.
Otherwise (without license), the tap changer has to be tested in manual mode.
Note: For detailed information about further test cards, test procedures and
templates refer to the CPC 100 User Manual.