CZ
Vacuum On-Load Tap Changer
Operation Instructions
HM 0.460.1101
Shanghai Huaming Power Equipment Co., Ltd.
Thank you for choosing our vacuum on-load tap
changer!
Prior to operating the vacuum on-load tap changer,
please be sure to read carefully operation instructions
HMO.460.1101
CONTENTS
1
SummaryĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ1
2
Structure of the tap changerĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 3
3
Operation principles of the tap changerĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ4
4
Technical dataĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ6
5
Accessories of the tap changerĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 7
6
Installation onto transformerĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ8
7
Inspection & MaintenanceĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ12
8
Documents attached with the tap changerĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ13
9
Notes for ordering and applicationĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 13
10
SupplementsĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 13
10.1
Drawing of the tap changer structureĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ14
10.2
Installation dimension of the tap changerĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ15
10.3
CZI OLTC overall dimension, 9 operation positionsĂĂĂĂĂĂĂĂĂĂĂĂĂĂ16
10.4
CZI OLTC overall dimension, 7 operation positionsĂĂĂĂĂĂĂĂĂĂĂĂĂĂ17
10.5
CZI OLTC overall dimension, 13 operation positionsĂĂĂĂĂĂĂĂĂĂĂĂĂ 18
10.6
CZ OLTC mounted on supporting frame, MDU on the right side, 9 positionsĂĂĂĂ19
10.7
CZ OLTC mounted on supporting frame, MDU on the left side,9 positionsĂĂĂĂĂ20
10.8
CZ OLTC mounted in enclosure, MDU on the right side, 7 positionsĂĂĂĂĂĂĂ21
10.9
CZ OLTC mounted in enclosure, MDU on the left side, 7 positionsĂĂĂĂĂĂĂĂ22
10.10 CZ OLTC mounted in enclosure, MDU on the right side, 9 positionsĂĂĂĂĂĂĂ23
10.11 CZ OLTC mounted in enclosure, MDU on the left side, 9 positionsĂĂĂĂĂĂĂĂ24
10.12 Disposal drawing of 3 units of single phase CZ OLTCĂĂĂĂĂĂĂĂĂĂĂĂĂ25
10.13 Installation dimension of SHM-1 motor drive unitĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 26
10.14 Installation dimension of CMA7 motor drive unitĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ27
10.15 Installation dimension of bevel gearĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 28
10.16 Operating position diagramĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 29
10.17 Connection diagramĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂĂ 30
1. Summary
CZ type vacuum on-load tap changer is suitable for dry transformer installed indoor, through
which the tap changes can be realized for voltage regulating under the status of transformer on load.
The CZ on-load tap changer, designed in single-phase structure, can be satisfied for any selectable
transformer winding connection. For dry type three-phase transformer,three sets of single-phase
CZ OLTC can be mechanical linked and operated by one unit of motor drive unit.
CZ OLTC consists of diverter switch and tap selector, by applying switching principle of fast
resistsnce transition, selects tapping terminals via tap selector and then switches under the load
through diverter switch in its tapping conversion process.
1.1. Main Characteristics of CZ on-load tap changer
a) Vacuum interrupter is designed to satisfy OLTC operation condition, thus to ensure that
OLTC has reliable quality and long operation life.
b)The vacuum interrupter are fixed completely in the insulation frame, it will not be interfered by the
moving of contact.
c) Vacuum interrupter works as arcing contact, there are special mechanical contacts carry the current
for long in main circuit, thus tap changer has good arc extinguishing capability and can be reliable
operated for long time.
Diverter Switch
d) Adopting double-resistor transition
structure in diverter switch, therefore
it can be used for the transformer
with bigger capacity.
Transmission
Mechanism
e) Energy accumulating system is with
compressed spring and adopting typical
triggering principle, to make tap changer
operation in reliable and stable.
Tap Selector
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HMO.460.1101
1.2 Main Technical Data
No.
On Load Tap Changer
CZ I 500
3 ġ CZ I 500
1
Number of Phase And Application
1
Single Phase
3
Any 3-phase
Connection
2
Max. Rated Through-Current (A)
3
Short-circuit
current test (kA)
500
Thermal (3s)
5
Dynamic (Peak)
12.5
4
Max. Rated Step Voltage (V)
900
5
Rated Step Capacity (kVA)
250
6
Max. Operating Positions
13, in linear regulation
7
Rated Frequency (Hz)
50 or 60
Insulation
8
To Ground
Highest Voltage For Equipment Um (kV)
40.5
Rated separate source AC
85
withstand voltage(kV/50Hz,1min)
Rated lightning impulse
200
withstand voltage (kV,1.2/50µs)
5
Rated separate source AC
Between Tap
In Service And
Pre-Selected
Tap
9
Internal
withstand voltage(kV/50Hz,1min)
20
Rated lightning impulse
withstand voltage (kV,1.2/50µs)
20
Rated separate source AC
Insulation
Across Fine
Tap Winding
withstand voltage(kV/50Hz,1min)
80
Rated lightning impulse
withstand voltage (kV,1.2/50µs)
10
Ambient Temperature of Operation (ņ)
-25ċ+65
11
Ambient Media of Operation
Air
12
Adopted Motor Drive Unit
SHM-III or CMA7
13
Electric Life
Not Less Than 300,000 Operations
14
Mechanical Life
Not Less Than 800,000 Operations
15
OLTC Weight (Excluding Motor Drive Unit, Approx.)
80
240
2
1.3 Designation of the CZ vacuum on-load tap changer
3 h CZ I
500 –
40.5– □
Number of operation positions
Highest voltage for equipment (kV)
Maximum rated through current (A)
Single phase
Type
3 pieces of single-phase OLTC operated by 1 unit of MDU
2. Structure of the tap changer
See supplement 9.1 Drawing of the tap changer structure.
The CZ on-load tap changer is consisted of tap selector and diverter switch. Stationary contacts of
the tap selector and output conductor row are installed respectively on two insulation plates
in parallel each other, and the moving contacts of the tap selector is driven by screw bar to
select tap terminal. Double stationary contacts in parallel connection are adopted for the tap selector,
so it is strong in current-loading capacity.
The output conductor row of the tap selector is linked to diverter switch via conducting wire,
and divided into odd side and even side. If the diverter switch operates on odd side, the moving
contacts of the tap selector on even side can be selected, and the diverter switch is driven by energy
accumulator and converted into even side after the selection completed. Thus, during next tap
conversion, the moving contacts of the selector on odd side can be selected.
Operation sequence of the tap selector and the diverter switch is guaranteed by links of
mechanical parts.
Transmission of the tap changer is realized via drive mechanism that is linked by horizontal
driving shaft and that also drives moving contacts of the tap selector to conduct tap-selection and
stores energy into the energy accumulator. When selection is finished, the energy accumulator releases
energy to drive vacuum interrupter of the diverter switch for performing tap changing
according to specified program “close”, “open”.
The diverter switch consists of four vacuum interrupters, one pair of main mechanical contact,
two sets of transition resistor and energy accumulating mechanism. The vacuum interrupters are
3
HMO.460.1101
fixed inside diverter switch, with many characteristics such as large switching capacity and long
service life. The main contacts are made of pure copper for lower temperature rising in long
term. Transition resistances are made of Ni-Cr alloy with performance of heavy heat resistance. The
energy accumulating mechanism is adopting principle of triggering after pass dead-point, it
is reliability in its operation.
3. Operation principles of the tap changer
3.1 Connection diagram of tap changer
Diverter switch
Tap selector
From the diagram, it can be seen that the tap changer is consisted of tap selector and diverter
switch. The tap changer is operating at position 6 in the drawing above.
3.2 Operation principles of the tap changer
The description below is for the tap changing process from operation position 6 to position 7.
3.2.1
Load current flows from tap terminal 6 via main contact B to terminal X for outputting. The
moving contact of the tap selector on odd side under no load condition moves from position 5
to position 7, shown in drawing below:
Tap selector
3.2.2
Diverter switch
After finishing tap selection, the diverter switch releases via energy accumulator, by which
the main contact of the diverter switch and vacuum interrupter is converted according the
program below.
4
First step:
The main contact B opens and load current IN outputs via vacuum interrupter Vb1.
Second step: Vacuum interrupter Vb1 opens, and load current IN outputs via transition resistance R
and vacuum interrupter Vb2.
Third step: Vacuum interrupter Va2 closes, the diverter switch is in middle-bridging status, load current
outputs via double-resistance and vacuum interrupters Vb2 ,Va2. Step voltage produces loop
current Ic in bridge circuit.
Fourth step: Vacuum interrupter Vb2 opens, load current is out put passing through single resistance R and
vacuum interrupter Va2.
5
HMO.460.1101
Fifth step: Vacuum interrupter Va1 closes, load current outputs via Va1.
Sixth step:
Main contact A closes, tap changing is completed and the tap changer on position 7.
Diverter switch
Tap selector
Whereas, for load current passing through from main contact A to contact B, its switching sequence
is similar to above.
4. Technical data
4.1
Rated switching capacity
The rated switching capacity of the tap changer depends on circuit structure of the tap changer and
switching capacity of the vacuum interrupter. The switching capacity of type CZ on-load tap
changer is shown in the following drawing.
According to requirements of IEC60214-1 (2003), the breaking capacity of the tap changer refers
to the maximum switching capacity of the tap changer for safety conversion of load, which shall
be the double rated switching capacity at least.
Step Voltage (V)
900
500
280
500
Rated Through Current (A)
Rated switching capacity curve of type CZ vacuum OLTC
6
4.2
Ambient temperature
Type CZ on-load tap changer is designed for being suitable to operate under ambient temperature
of –25ć~+65ć, user shall arrange some right measures to avoid condensation and freeze on the
tap changer.
4.3
Insulation grade
Insulation grade of type CZ is including insulation to ground and internal insulation of the tap
changer. The insulation grade to ground is considered as 35 kV insulation grade. The internal
insulation of the tap changer is considered according to the insulation grades satisfied to each part
of a general dry transformer, the values are as follows:
Insulation grade
Rated power frequency
withstand voltage
( kV, 50 Hz, 1min )
Rated lightning impulse
withstand voltage
( kV, 1.2/50 )
Insulation to ground and insulation
between phases
85
200
Between tap in service and
pre-selected tap
5
20
Across fine tap winding
20
80
Note: If the transformer is placed in a cabinet grounded, sufficient insulation space to ground
shall be considered between the conducting parts of the tap changer and the cabinet.
5. Accessories of the tap changer
5.1
Motor drive unit type CMA7
It has all of characteristics for controlling and driving type CZ on-load tap changer. Its operation
manner is a step-operation, that is, one operation order is for finishing one-step operation, then
stopping.
Motor drive unit CMA7 and CZ OLTC is linked by horizotal drive shaft and vertical drive shaft
through bevel gear unit.
For more details please refer to HMO.460.302 <Motor Drive Unit Type CMA7 Operation
Instructions >.
5.2
Intelligence motor drive unit type SHM-1
The tap changer can also be operated and driven by type SHM-1 motor drive unit, which is an
7
HMO.460.1101
intelligent mechanism adopted modular and standardization design principles and computer
program encoder.
For more details please refer to <SHM Intelligence Motor Drive Unit Operation Instructions>.
5.3
Horizontal drive shaft
The horizontal drive shaft is for realizing the mechanical link between tap changer and bevel gear
unit, which is made of insulation materials.
Length of drive shaft is determined according to insulation requirement between two single phases
of tap changers, and between tap changer and MDU.
Please refer to 'Supplement 10.12' which is specified minimum insulation distance between two
single phases of tap changers.
5.4. Vertical drive shaft
The vertical drive shaft is for realizing the mechanical link between motor drive unit and bevel
gear, which is made of steel pipe in square section.
6. Installation onto transformer
Type CZ vacuum on-load tap changer can be installed inside of cabinet or onto supporting shelf of
transformer. Please see the following pictures.
The on load tap changer must be installed with transformer specified in the order. Installation and
test of the on load tap changer shall be conducted by professionals.
Type CZ is installed inside cabinet
Type CZ is installed onto
supporting frame of transformer
Type CZ is installed on supporting frame
separate from the transformer
8
6.1
Shipping list of CZ vacuum on-load tap changer
6.1.1 On-load tap changer type CZ body
6.1.2 Motor drive unit type CMA7 or SHM-1
6.1.3 Bevel gear mechanism
6.1.4 Vertical drive shaft and horizontal drive shafts.
6.1.5 Remote position indicator or automatic voltage regulator.
6.1.6 Other necessary accessories.
6.2
Type CZ is installed onto supporting frame
6.2.1 Mounting & installation of the tap changer
Due to its structure reason, the tap changer must be installed vertically. Use six M12 bolts to fasten
tap changer to the bracket vertically via the six 13 mm holes on the insulating panel locating on the
top of the tap changer. The both end of the flat head socket cap screw should be covered by shielding
cap, please see below installation sketch. Please see supplement 10.12 for recommended insulation
distance between the phases of the tap changer, adequate distance shall also be ensured from
conducting parts of the tap changer to transformer winding, and bottom of the tap changer to the
ground.
Shielding cap
6-M12 Flat head
socket cap screw
A-A
Supporting frame
A↑　－－　]TžXZ
Z`W
↑A
－－
Z]W
tap changer
Installation Sketch
9
HMO.460.1101
6.2.2 Installation of the motor drive unit
The mounting & installation of the motor drive unit includes using four bolts to fasten the motor
drive unit to the support bracket via the four holes at the bottom. After installation, the output
shaft of the motor drive unit shall be lined up with the drive shaft of the tap changer.
6.2.3
Installation of the bevel gear box
Use two M16 bolts to mount the bottom of the bevel gear box to the support bracket. The input &
output shaft shall be lined up with the drive shaft of the motor drive unit & the tap changer.
6.2.4
Installation of the drive shaft
6.2.4.1 Installation of the vertical drive shaft
The vertical drive shaft is a stainless steel pipe with square cross section. It is cut according to the
actual dimension. Both its ends are mounted to the coupling joints which will drive the shaft via
pins.
6.2.4.2 Installation of the horizontal drive shaft
Cut the horizontal insulation drive shaft according to actual length required, the cutting section
should be coated with insulation paint. Connecte horizontal drive shaft to the tap changer via joints.
Keep around 3mm gap in axis direction when doing connection, meanwhile to ensure the axis centre
of the joints should be at the same line, the error should not be over 8mm.
Unit: mm
Note: During the installation, the operating position of the tap changer & the motor drive unit
must be identical.
10
The position of the motor drive unit can be observed through the position indicating window on
the cover of the motor drive unit. The position of the tap changer can be determined by measuring
the connection between the taps of selector & the current take off terminal by using a current meter.
The default position of the tap changer & the motor drive unit is set to the adjustment position.
Please do not change unintentionally.
6.2.5 Adjustment of the tap changer
After connecting the tap changer, motor drive unit & the bevel gear box, adjustment shall be
performed before actual operation.
6.2.5.1 Connection adjustment of the motor drive unit
First, adjust the link between phase A (which is close to the motor drive unit) of the tap changer
and the motor drive unit. Adjust to reach a balance of turns both clockwise and counter clockwise.
Refer to the operation instructions of the motor drive unit for details.
6.2.5.2 Three phase synchronism adjustment of the tap changer
Use Phase A as a reference, adjust Phase B and Phase C of the tap changer to reach consistency.
The synchronism is determined by the total turns of the hand crank of the motor drive unit before
the energy accumulator is released. The degree of asynchronism shall be kept within 3/4 turns.
6.3
Type CZ is installed inside cabinet
We can supply tap changer with cabinet as requirement. In this case, linking and adjusting for tap
changer and motor drive unit have performed before delivery, so it is not necessary to link and
adjust by user.
The tap changer cabinet has to be installed onto plane ground with 4 pieces of proper connection
bolts.
6.4
Electrical connection
Connect transformer windings to tap changer terminals according to connection diagram (please
refer to drawings in clause 10.17). During connection, keep no force of the wires applied on the tap
changers and the connections shall be reliable and fixed after finishing the connection.
6.5
Operation test and ratio measuring.
Conduct two operations for whole cycle. Check if tap changer position is consistent with motor
drive unit position during operation process. In the meantime, it should be measured ratio and
direct current resistance of the transformer. It can be put into operation only if all are confirmed
correct.
11
HMO.460.1101
7
Inspection & Maintenance
General inspection could be carried out by trained personnel; however, all maintenance should be
performed by Huaming-trained personnel.
Interval
Measures
a. Remove dust from surface with a dry rag.
b. Examine all external fasteners whether they
External inspection
are loose, and operate tap changer one full
every year
switching cycle without load, while listen any
abnormal sound emitting from inside.
Lubricate inside parts and check internal
Completion of
fasteners whether they are loose and whether
100,000 switching or
contacts have been worn excessively( points to
after 3 years
be lubricated as in figure 1)
Completion of
200,000 operations
Check vacuum interrupters
Completion of
300,000 operations
Replace vacuum interrupters
Completion of
800,000 operations
Replace on-load tap changer
Personnel
May be performed by
qualified and trained
personnel
Must be performed by
Huaming-trained
personnel
Must be performed by
Huaming-trained
personnel
Must be performed by
Huaming-trained
personnel
1. Energy accumulator mechanism
2. Reversing gear
3. Transmission gear
4. Fixed contacts
5. Moving contacts
6. Screw bar
7. Fixed contacts
8. Main fixed and moving contacts
Figure 1: Points to be lubricated
12
8. Documents attached with the tap changer
8.1 Qualification certificate;
8.2 Routine test report;
8.3 Vacuum on-load tap changer type CZ operating instructions;
8.4 Motor drive unit operating instructions and remote indicator or AVR manual.
9. Notes for ordering and application
9.1
The following data shall be offered by client when send an order:
9.1.1
Capacity of the transformer;
9.1.2
Voltage class of the transformer;
9.1.3
Max. tapping current;
9.1.4
Step voltage in the phase;
9.1.5
Drawing of transformer winding and connection model;
9.1.6
Voltage adjustment accuracy;
9.1.7
Operation positions;
9.2
9.2.1
Application notes
The product shall be stored at a dry place with ventilation, no heavy vibration and no corrosive
gases;
9.2.2
User shall record the tap changer operation during application for future analysis and treatment if
trouble happens;
9.2.3
Guaranteed term is 18 Months after delivery and 12 months after commissioning which ever
comes first.
10. Supplements
13
HMO.460.1101
10.1
Drawing of the tap changer structure
1. Vacuum interrupter
2. Transmission mechanism
3. Axis connected to horizontal drive shaft
4. Fixed contact
5. Moving contact
6. Tap selector
7. Insulation plate
8. Induction row
9. Screw bar
10. Connection lead
11. Main moving contact
12. Main fixed contact
13. Transition resistance
14. Diverter switch
14
10.2 Installation dimension of the tap changer
390
1
6
3
4
192.5
72
2
3
Φ1
135
67
5
7
490
1. Suspended plate for installation
5. Axis connected to horizontal drive shaft
2. Wiring terminals
6. Induction bar
3. Diverter switch
7. Tap selector
4. Transmission mechanism
Unit: mm
15
HMO.460.1101
10.3
CZI OLTC overall dimension, 9 operation positions
Unit: mm
16
10.4
CZI OLTC overall dimension, 7 operation positions
Unit: mm
17
HMO.460.1101
10.5
CZI OLTC overall dimension, 13 operation positions
Unit: mm
18
10.6
CZ OLTC mounted on supporting frame, MDU on the right side, 9 positions
Unit: mm
19
HMO.460.1101
10.7
CZ OLTC mounted on supporting frame, MDU on the left side,9 positions
Unit: mm
20
10.8
CZ OLTC mounted in enclosure, MDU on the right side, 7 positions
Unit: mm
21
HMO.460.1101
10.9
CZ OLTC mounted in enclosure, MDU on the left side, 7 positions
Unit: mm
22
10.10
CZ OLTC mounted in enclosure, MDU on the right side, 9 positions
Unit: mm
23
HMO.460.1101
10.11
CZ OLTC mounted in enclosure, MDU on the left side, 9 positions
Unit: mm
24
10.12
Disposal drawing of 3 units of single phase CZ OLTC
Unit: mm
25
HMO.460.1101
10.13
Installation dimension of SHM-1 motor drive unit
earthing bolt
mounting hole
K view
Unit: mm
26
10.14 Installation dimension of CMA7 motor drive unit
Unit: mm
27
HMO.460.1101
10.15 Installation dimension of bevel gear
Unit: mm
28
10.16 Operating position diagram
5 positions
7 positions
A (B; C)
A (B; C)
9 positions
13 positions
A (B; C)
A (B; C)
X (Y; Z)
X (Y; Z)
X (Y; Z)
X (Y; Z)
A
B
C
star connection
A
B
C
delta connection
29
HMO.460.1101
10.17 Connection diagram
X (Y; Z)
Current output
A (B; C)
Diverter switch
Tap selector
●　Indication position
1 2 3 4 5 6 7 8 9
Position of tap selector
1 2 3 4 5 6 7 8 9
Operating position
Adjusting position ●
9
5
30
SHANGHAI HUAMING POWER EQUIPMENT CO.,LTD.
Address: 977 Tong Pu Road, Shanghai, P.R.China 200333
Tel: +86 21 5270 3965 (direct)
+86 21 5270 8966 Ext.
8688/8123/8698/8158/8110/8658
Fax: +86 21 5270 2715
Web:www.huaming.com
E-mail: export@huaming.com