ABB DCT880 User manual

DCT880
Service Manual
DCT880 Thyristor power controller (20 A … 4160 A)


3
Safety Instructions
Chapter overview
This chapter contains the safety instructions you must follow when installing, operating and servicing the
thyristor power controller. If ignored, physical injury or death may follow, or damage may occur to the thyristor
power controller or the connected equipment. Read the safety instructions before you work on the unit.
To which products this chapter applies
The information is valid for the whole range of the product DCT880.
Usage of warnings and notes
There are two types of safety instructions throughout this manual: warnings and notes. Warnings caution you
about conditions, which can result in serious injury or death and/or damage to the equipment, and advice on
how to avoid the danger. Notes draw attention to a particular condition or fact, or give information on a
subject. The warning symbols are used as follows:
Dangerous voltage warning warns of high voltage, which can cause physical injury or death
and/or damage to the equipment.
General danger warning warns about conditions, other than those caused by electricity, which
can result in physical injury or death and/or damage to the equipment.
Electrostatic sensitive devices warning warns of electrostatic discharge, which can damage
the equipment.
Installation and maintenance work
These warnings are intended for all who work on the thyristor power controller, the cables or the connected
equipment. Ignoring the instructions can cause physical injury or death and/or damage to the equipment.
WARNING!
Only qualified electricians are allowed to install and maintain the thyristor power
controller!
−
Never work on the thyristor power controller, the cables or the connected equipment when
main power is applied. Always ensure by measuring with a multimeter (impedance at least
1 Mohm) that:
1. Voltage between thyristor power controller input phases U1, V1, W1 and the frame is
close to 0 V.
2. Voltage between thyristor power controller output phas
es U2, V2, W2 and the frame is
close to 0 V.
−
Do not work on the control cables when power is applied to the thyristor power controller or
to the external control circuits. Externally supplied control circuits may cause dangerous
voltages inside the thyristor power controller even when the main power on the thyristor
power controller is switched off.
−
Do not make any insulation resistance or voltage withstand tests on the thyristor power
controller.
−
Isolate the cables to the equipment from the thyristor power controller when testing the
insulation resistance or voltage withstand of the cables or the equipment.
−
When reconnecting the cables to the equipment, always check that the U2, V2 and W2
cables are connected with the proper terminal.
Note
s:
−
The output phase cable terminals on the thyristor power controller are at a dangerously high
voltage when the main power is on.
−
Depending on the external wiring, dangerous voltages (115 V, 220 V or 230 V) may be
present on the relay outputs of the thyristor power controller (e.g. XRO1 … XRO3).
−
DCT880 with enclosure extension: Before working on the thyristor power controller, isolate
the whole thyristor power controller system from the supply.
Safety Instructions
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Grounding
These instructions are intended for all who are responsible for the grounding of the thyristor power controller.
Incorrect grounding can cause physical injury, death and/or equipment malfunction and increase
electromagnetic interference.
WARNING!
−
Ground the thyristor power controller, the connected equipment and adjoining devices to
ensure personnel safety in all circumstances, and to reduce electromagnetic emission and
pick-up.
−
Make sure that grounding conductors are adequately sized and marked as required by safety
regulations.
−
In a multiple thyristor power controller installation, connect each thyristor power controller
separately to protective earth (PE).
−
Minimize EMC emission and make a 360° high frequency grounding (e.g. conductive
sleeves) of screened cable entries at the cabinet lead-through plate.
Note
s:
−
Power cable shields are suitable as equipment grounding conductors only when adequately
sized to meet safety regulations.
−
As the normal leakage current of the thyristor power controller is higher than 3.5 mAAC or
10 mADC (stated by EN 50178, 5.2.11.1), a fixed protective earth connection is required.
Printed circuit boards
These instructions are intended for all who handle the circuit boards. Ignoring the following instructions can
cause damage to the equipment.
WARNING!
The printed circuit boards contain compo
nents sensitive to electrostatic discharge. Wear a
grounding wristband when handling the boards. Touch the boards only when necessary.
ABB order no.: 3ADV050035P0001
Safety Instructions
3ADW000449R0101 DCT880 Service Manual e a

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Mechanical installation
These notes are intended for all who install the thyristor power controller. Handle the unit carefully to avoid
damage and injury.
WARNING!
−
DCT880 sizes T4 and T5: The thyristor power controller is heavy. Do not lift it alone. Do not
lift the unit by the front cover. Place units T4 and T5 only on its back.
−
Make sure that dust from drilling does not enter the thyristor power controller when installing.
Electrically conductive dust inside the unit may cause damage or lead to malfunction.
−
Ensure sufficient cooling.
−Do not fasten the thyristor power controller by riveting or welding.
Operation
These warnings are intended for all who plan the operation of the thyristor power controller or operate the
thyristor power controller. Ignoring the instructions can cause physical injury or death and/or damage to the
equipment.
WARNING!
−
Before adjusting the thyristor power controller and putting it into service, make sure that all
connected equipment is suitable for operation throughout the voltage/current range provided
by the thyristor power controller.
−
Do not control the connected equipment with the disconnecting device (disconnecting
mains); instead, use the control panel keys and , or commands via the I/O board of
the thyristor power controller.
−
Mains connection
You can use a disconnect switch (with fuses) to disconnect the electrical components of the
thyristor power controller from the mains for installation and maintenance work. The type of
disconnect switch used must be as per EN 60947-3, Class B, so as to comply with EU
regulations, or a circuit-breaker type which switches off the load circuit by means of an
auxiliary contact causing the breaker's main contacts to open. The mains disconnect must be
locked in its "OPEN" position during any installation and maintenance work.
−
EMERGENCY POWER OFF buttons must be installed at each control desk and at all other
control panels requiring an emergency off function. Pressing the Stop button on the control
panel of the thyristor power controller will not cause an emergency off by the thyristor power
controller and it will not disconnect the thyristor power controller from any dangerous
potential.
−
To avoid unintentional operating states, or to shut the unit down in case of any imminent
danger according to the standards in the safety instructions it is not sufficient to merely shut
down the thyristor power controller via signals Run or Enable or from control panel or PC
tool.
−
Intended use
The operating instructions cannot take into consideration every possible case of
configuration, operation or maintenance. Thus, they mainly give such advice only, which is
required by qualified personnel for normal operation of the machines and devices in industrial
installations.
If in special cases the electrical machines and devices are intended for use in non-industrial
installations - which may require stricter safety regulations (e.g. protection against contact by
children or similar) - these additional safety measures for the installation must be provided by
the customer during assembly.
Note:
−
When the control location is not set to Local, the Stop key on the control panel will not stop
the thyristor power controller. To stop the thyristor power controller using the control panel,
press the Loc/Rem key and then the Stop key .
Safety Instructions
3ADW000449R0101 DCT880 Service Manual e a

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Table of contents
Safety Instructions 3
Table of contents 6
DCT880 Manuals and Tools 8
List of manuals............................................................................................................................................... 8
Documentation............................................................................................................................................... 9
DCT880 Information....................................................................................................................................... 9
Introduction 10
Chapter overview ..................................................................................................................................... 10
Before You Start ...................................................................................................................................... 10
What this manual contains....................................................................................................................... 10
Target group ............................................................................................................................................ 10
Associated publications ........................................................................................................................... 10
Storage and transport .............................................................................................................................. 10
Name plate................................................................................................................................................... 11
Type code .................................................................................................................................................... 11
Ratings ......................................................................................................................................................... 11
Voltage ratings ......................................................................................................................................... 11
400 V / 525 V units, current and power ratings ....................................................................................... 12
690 V units, current and power ratings .................................................................................................... 12
Fault Tracing Thyristors 14
Tools ............................................................................................................................................................ 14
For commissioning and fault tracing ........................................................................................................ 14
Additionally for service and preventive maintenance .............................................................................. 15
How to detect a faulty thyristor .................................................................................................................... 15
A fuse is blown......................................................................................................................................... 15
Output current measured by an oscilloscope .......................................................................................... 15
Thyristor diagnosis................................................................................................................................... 16
How to find a faulty thyristor ........................................................................................................................ 16
Standard thyristor power controllers size T1 … T4 (20 A ... 740 A), without +S500 ............................... 16
Blown fuses.............................................................................................................................................. 16
Faulty thyristor ......................................................................................................................................... 16
Standard thyristor power controllers size T5 (890 A … 960 A), without +S500 ...................................... 17
Blown fuses.............................................................................................................................................. 17
Faulty thyristor ......................................................................................................................................... 17
Thyristor power controllers size T1 … T4 (20 A ... 740 A), with +S500................................................... 17
Blown fuses.............................................................................................................................................. 18
Faulty thyristor ......................................................................................................................................... 18
Handling the Semiconductors 19
General Instruction how to handle semiconductors..................................................................................... 19
Exchange thyristors sizes T1 … T4 20
Installation of thyristor modules in thyristor power controllers size T1 … T4 (20 A ... 740 A) ..................... 20
Required tools.......................................................................................................................................... 20
Find faulty thyristor modules.................................................................................................................... 20
Remove faulty thyristor modules ............................................................................................................. 21
Install new thyristor modules ................................................................................................................... 26
Thyristor module terminals ...................................................................................................................... 27
Exchange thyristors size T5 29
Installation of thyristor modules in thyristor power controllers size T5 (890 A … 960 A) ............................ 29
Table of contents
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Required tools ..........................................................................................................................................29
Find faulty thyristor modules.....................................................................................................................29
Remove faulty thyristor modules ..............................................................................................................30
Install new thyristor modules ....................................................................................................................39
Thyristor module location in T5 units........................................................................................................40
Thyristor module terminals .......................................................................................................................40
Exchange SDCS-CON-F 41
General .........................................................................................................................................................41
Required Tools .........................................................................................................................................41
Overview SDCS-CON-H exchange ..........................................................................................................41
Service 45
Exchange cooling fans sizes T1 … T3 (two fans) ........................................................................................45
Exchange cooling fans size T3 (four fans) ...................................................................................................48
Exchange cooling fans size T4.....................................................................................................................51
Exchange cooling fans size T5.....................................................................................................................55
Exchange of internal semiconductor fuses in thyristor power controllers size T1 … T4 (20 A ... 740 A) ....56
Required tools ..........................................................................................................................................56
Find blown semiconductor fuses ..............................................................................................................56
Remove blown semiconductor fuses........................................................................................................56
Install new semiconductor fuse(s) ............................................................................................................61
Exchange of internal semiconductor fuses in thyristor power controllers size T5 (890 A … 960 A)............62
Required tools ..........................................................................................................................................62
Find blown semiconductor fuses ..............................................................................................................62
Remove blown semiconductor fuses........................................................................................................62
Install new semiconductor fuse(s) ............................................................................................................69
DCT880 firmware download .........................................................................................................................70
General .....................................................................................................................................................70
Download SDCS-CON-H firmware using the Drive loader 2.x.................................................................70
Set type code................................................................................................................................................75
Preventive Maintenance 76
Recommended regular maintenance ...........................................................................................................77
Maintenance schedule..................................................................................................................................77
Annual preventive maintenance ...................................................................................................................78
3 years preventive maintenance ..................................................................................................................79
6 years preventive maintenance ..................................................................................................................80
9 years preventive maintenance ..................................................................................................................81
Preventive maintenance Checklist DCT880.................................................................................................82
Appendix A: Spare Parts List 84
T1 (20 A … 125 A)........................................................................................................................................84
T2 (160 A … 245 A)......................................................................................................................................85
T3 (325 A … 420 A)......................................................................................................................................86
T4 (550 A … 740 A)......................................................................................................................................87
T5 (890 A … 960 A)......................................................................................................................................88
Table of contents
3ADW000449R0101 DCT880 Service Manual e a

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DCT880 Manuals and Tools
List of manuals
Language
Publication number
E
D
I
ES
F
CN
RU
DCT880 Quick Guide
3ADW000435
x
p
p
p
p
DCT880 Units
DCT880 Flyer
3ADW000429
x
x
x
x
x
x
x
DCT880 Technical Catalog
p
DCT880 Manual
3ADW000431
x
x
DCT880 Power Optimizer Control Manual
3ADW000441
x
DCT880 Multitap Control Manual
3ADW000440
x
ACS-AP-x assistant control panels user’s manual
3AUA0000085685
Option manuals and guides
SDCS-DPI-H01 panel bus adapter module
HW DCT880 0001E
x
DPMP-01 mounting platform for ACS-AP control
panel
3AUA0000100140
x
DPMP-02 mounting platform for ACS-AP control
panel
3AUA0000136205
x
FCAN-01 CANopen adapter module
3AFE68615500
3AUA0000121752
x
x
FDNA-01 DeviceNet™ adapter module
3AFE68573360
x
FECA-01 EtherCAT adapter module
3AUA0000068940
3AUA0000083936
x
x
FENA-01/-11/-21 Ethernet adapter module
3AUA0000093568
x
FEPL-02 Ethernet POWERLINK adapter module
3AUA0000123527
3AUA0000133138
x
x
FPBA-01 PROFIBUS DP adapter module
3AFE68573271
3AFE68989078
x
x
FSCA-01 RS-485 adapter module
3AUA0000109533
x
Drive (IEC61131-3) application programming
manual
3AUA0000127808
x
Tool and maintenance manuals and guides
Drive composer PC tool
3AUA0000094606
x
NETA-21 remote monitoring tool
3AUA00000969391
x
NETA-21 remote monitoring tool installation and
startup guide
3AUA0000096881
x
DCT880 Service Manual
3ADW000449
x
x = existing p = planned
Status 09.2015
DCT880 Manuals list f e.docx
Manuals and Tools
3ADW000449R0101 DCT880 Service Manual e a

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Documentation
The structure of the documentation is according to the following system:
−The DCT880 Technical Catalog contains information to engineer complete thyristor power controller
systems.
−The DCT880 Manual contains information about:
1. Unit dimensions, electronic boards, fans and auxiliary parts.
2. Mechanical and electrical installation.
3. Firmware and parameter settings.
4. Start-up and maintenance of the entire thyristor power controller.
5. Faults, warnings and information for trouble shooting.
−The DCT880 Service Manual contains information for maintenance and repair of the thyristor power
controller.
−Additional information about technical accessories (e.g. hardware extension or fieldbus adapter) are
handled by separate manuals – see table above.
DCT880 Information
All Information on DCT880 is also available on the internet:
−DCT880 documentation.
−PC tool (Drive composer entry) for parameterization, commissioning and service.
−Drive loader 2.x for firmware download.
−DCT880 firmware.
Manuals and Tools
3ADW000449R0101 DCT880 Service Manual e a

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Introduction
Chapter overview
This chapter describes the purpose, contents and the intended use of this manual.
Before You Start
The purpose of this service manual is to provide detailed information on how to service DCT880 thyristor
power controllers. The Safety instructions at the beginning of this manual need to be studied before
attempting any work on or with the thyristor power controller. Read this manual before servicing the thyristor
power controller.
What this manual contains
The Safety instructions are at the beginning of this manual.
Introduction, the chapter you are currently reading, introduces you to this manual and the thyristor power
controller rating plate.
Fault Tracing Thyristors, this chapter describes how to detect and select a faulty thyristor.
Handling the Semiconductors, this chapter describes the handling of thyristors and thyristor modules.
Exchange thyristors sizes T1 … T4, this chapter describes the exchange of thyristors in thyristor power
controllers sizes T1 ... T4.
Exchange thyristors size T5, this chapter describes the exchange of thyristors in thyristor power controllers
size T5.
Exchange of SDCS-CON-H, this chapter describes the exchange of a SDCS-CON-H.
Service, this chapter contains hardware change information, firmware download and technical hints.
Preventive Maintenance, this chapter describes preventive maintenance of thyristor converters.
Appendix A: Spare Parts list, Appendix A contains the spare parts list.
Target group
This manual is designed to help those responsible for planning, installing, starting up and servicing thyristor
power controllers.
These people should possess:
−Basic knowledge of physics, electrical engineering, electrical wiring principles, components as well as
symbols used in electrical engineering.
−Basic experience with thyristor power controllers.
Associated publications
A list of associated publications is published on the inner page of this manual’s cover see List of manuals.
Storage and transport
If the unit has been in storage prior to installation or is transported to another location, care must be taken to
ensure that the environmental conditions are complied with (see DCT880 Manual).
Introduction
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Name plate
For purposes of identification, each thyristor power controller is fitted with name plates, stating the type code
and the serial number, which serve for each unit’s individual identification.
The type code contains information about the characteristics and the configuration of the unit.
Production year
Rated input voltage
Rated output current
2015 and week 07
Rated input current
Rated output power
Rated fan voltage
Type code
The type code contains information on the specifications and configuration of the thyristor power controller:
The thyristor power controller’s basic type code: DCT880-AAB-CCCC-DD-E
Product family:
DCT880
Type:
AA
= W0
Standard
Power part type:
B
= 2
Two-leg anti-parallel circuit
= 3
Three-leg anti-parallel circuit
Unit type:
CCCC
=
Rated AC current (RMS)
Rated AC voltage:
DD
= 04
= 05
= 07
110 V
AC
… 400 V
AC
110 VAC … 525 VAC
315 VAC … 690 VAC
Revision code:
E
= 0
Standard
Ratings
Voltage ratings
Mains voltage
UV1N [VAC]
Output voltage
UV2N [VAC]
Voltage
class
110
110
04
230
230
04
380
380
04
400
400
04
415
415
04
440
440
05
460
460
05
480
480
05
500
500
05
525
525
05
660
660
07
690
690
07
Introduction
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12
400 V / 525 V units, current and power ratings
Three-leg anti-parallel units (W03).
Size
I
[A] (RMS)
P
out
[kW] ①
P
out
[kW] ②
P
loss
W03
[kW]
P
loss
W02
[kW]
Air flow
[m
3
/h]
Auxiliary
voltage
T1
20
13
17
0.13
0.09
no fan
+24 V
DC
, ±10 %
35
24
30
0.19
0.14
55
38
47
0.29
0.21
132
80
55
69
0.32
0.23
100
69
86
0.41
0.28
125
86
108
0.50
0.34
T2
160
110
138
0.67
0.46
200
138
173
0.69
0.47
245
169
212
0.86
0.58
T3
325
225
281
1.01
0.69
360
249
311
1.14
0.78
420
291
363
1.32
0.90
264
T4
550
381
476
1.84
1.25
925
675
467
584
2.06
1.40
740
512
640
2.29
1.55
1860
T5
890
616
770
3.50
-
800
960
-
-
-
2.90
①Power ratings for a 3-phase load in star configuration at 400 VAC (e.g. √3 ∗20 A ∗400 V / 1000 = 13 kW)
②Power ratings for a 3-phase load in star configuration at 500 VAC (e.g. √3 ∗20 A ∗500 V / 1000 = 17 kW)
690 V units, current and power ratings
Three-leg anti-parallel units (W03).
Size
I
[A] (RMS)
P
out
[kW] ③
P
loss
W03
[kW]
P
loss
W02
[kW]
Air flow
[m
3
/h]
Auxiliary
voltage
T1
35
42
0.19
0.14
132
+24 V
DC
, ±10 %
80
95
0.32
0.23
100
120
0.41
0.28
T2
160
191
0.67
0.46
200
-
-
0.47
T3
360
430
1.14
0.78
T4
630
753
2.01
1.33
925
T5
890
1064
3.50
-
800
960
-
-
2.90
③Power ratings for a 3-phase load in star configuration at 690 VAC (e.g. √3 ∗20 A ∗690 V / 1000 = 23 kW)
Introduction
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13
Current ratings with 50 Hz and 60 Hz supplies see below. The current ratings are based on an ambient
temperature of maximum 40°C and an elevation of maximum 1000 m above mean sea level:
Size
I
[A] (RMS)
Thyristor power controller
400 V / 525 V
Thyristor power controller
690 V
T1
20
DCT880-W0x-0020-04/05
-
35
DCT880-W0x-0035-04/05
DCT880-W0x-0035-07
55
DCT880-W0x-0055-04/05
-
80
DCT880-W0x-0080-04/05
DCT880-W0x-0080-07
100
DCT880-W0x-0100-04/05
DCT880-W0x-0100-07
125
DCT880-W0x-0125-04/05
-
T2
160
DCT880-W0x-0160-04/05
DCT880-W0x-0160-07
200
DCT880-W0x-0200-04/05
DCT880-W02-0200-07
245
DCT880-W0x-0245-04/05
-
T3
325
DCT880-W0x-0325-04/05
-
360
DCT880-W0x-0360-04/05
DCT880-W0x-0360-07
420
DCT880-W0x-0420-04/05
-
T4
550
DCT880-W0x-0550-04/05
-
630
-
DCT880-W0x-0630-07
675
DCT880-W0x-0675-04/05
-
740
DCT880-W0x-0740-04/05
-
T5
890
DCT880-W03-0890-04/05
DCT880-W03-0890-07
960
DCT880-W02-0960-04/05
DCT880-W02-0960-07
Note:
Input current = output current
Introduction
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Fault Tracing Thyristors
Tools
For commissioning and fault tracing
Following software tool is mandatory:
−Drive composer pro.
Following tools are mandatory in addition to standard tools:
−An oscilloscope including memory function with either galvanically isolating transformer or isolating
amplifier (probe) for safe measurements. It can also be a hand held (portable) oscilloscope.
−A clamp on current probe.
−A voltmeter (at least CAT III 1000 V).
−1000 V probes and test leads.
−An ESD-field service kit (ABB Service
Finland code 0001ESD / MS-Antistatic).
Make sure that all equipment in use is suitable for the voltage level applied to the power part!
Fault Tracing Thyristors
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Additionally for service and preventive maintenance
Following additional tools are mandatory for cleaning:
−An ESD safe blower / ESD vacuum cleaner
(ABB Service Finland code 0006ESD /
MUNTZ 555-ESD-S-E).
How to detect a faulty thyristor
Thyristor problems can be noticed differently:
A fuse is blown
This is an indication that a strong overcurrent has happened due to one of the following reasons:
−A shorted thyristor.
−A malfunction of the control electronics, e.g. wrong firing pulses (no thyristor defective).
−An external short circuit at the output terminals of the thyristor power controller without sufficient load.
Output current measured by an oscilloscope
Connect an oscilloscope to the output and check for the proper current (e.g. phase angle control):
Fault Tracing Thyristors
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Thyristor diagnosis
In addition, the thyristor diagnosis provided by the firmware can be used:
−Under construction.
How to find a faulty thyristor
If a blown fuse is suspected, the problem is caused most often by a faulty thyristor. To make sure, that a
thyristor is the reason and needs to be exchanged fault tracing must be done.
In general make sure, that all Safety instructions given within this manual or within the
safety instructions, related to the application itself, are obeyed.
Standard thyristor power controllers size T1 … T4 (20 A ... 740 A), without +S500
Standard thyristor power controllers, without +S500. External semiconductor fuses are required.
−The thyristor power controller must be disconnected from the mains.
Blown fuses
−Using the OHM function of a normal multimeter, measurements must be made from both sides of the
semiconductor fuses (e.g. L1 to U1, L2 to V1 and L3 to W1):
Faulty thyristor
−Using the OHM function of a normal multimeter, measurements must be made from both sides of the
thyristor power controller (e.g. U1 to U2, V1 to V2 and W1 to W2).
−Normally, each measurement should show high resistance (> 1 kΩ).
−Target: find a short circuit, indicated by low resistance (< 1 Ω) (destroyed thyristor).
−If the Thyristor power controller is designed with thyristor modules, then a module consists of two
thyristors. In this case, it is sufficient to know which thyristor module has a defective thyristor because the
complete module must be replaced.
−After a thyristor module is replaced, the above-mentioned measurement should be done another time to
make sure that all faulty thyristors have been detected!
Fault Tracing Thyristors
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Note:
The RC / snubber circuit could also cause 0 Ωresult for a short time.
The measurement, showing less resistance than 1 Ωshould be made a second time with test leads applied to
the terminals with opposite polarity; if this measurement shows the same result, one or two thyristors located
in that path are faulty; they need to be replaced.
Standard thyristor power controllers size T5 (890 A … 960 A), without +S500
Standard thyristor power controllers, without +S500. Internal semiconductor fuses are included.
−The thyristor power controller must be disconnected from the mains.
Blown fuses
−Using the OHM function of a normal multimeter, measurements must be made from both sides of the
semiconductor fuses (e.g. U1 to thyristor, V1 to thyristor and W1 to thyristor):
Faulty thyristor
−Make sure, the internal fuses are fine.
−Using the OHM function of a normal multimeter, measurements must be made from both sides of the
thyristor power controller (e.g. U1 to U2, V1 to V2 and W1 to W2).
−Normally, each measurement should show high resistance (> 1 kΩ).
−Target: find a short circuit, indicated by low resistance (< 1 Ω) (destroyed thyristor).
−If the Thyristor power controller is designed with thyristor modules, then a module consists of two
thyristors. In this case, it is sufficient to know which thyristor module has a defective thyristor because the
complete module must be replaced.
−After a thyristor module is replaced, the above-mentioned measurement should be done another time to
make sure that all faulty thyristors have been detected!
Note:
The RC / snubber circuit could also cause 0 Ωresult for a short time.
The measurement, showing less resistance than 1 Ωshould be made a second time with test leads applied to
the terminals with opposite polarity; if this measurement shows the same result, one or two thyristors located
in that path are faulty; they need to be replaced.
Thyristor power controllers size T1 … T4 (20 A ... 740 A), with +S500
Thyristor power controllers, with +S500. Internal semiconductor fuses are included.
−The thyristor power controller must be disconnected from the mains.
Fault Tracing Thyristors
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Blown fuses
−Using the OHM function of a normal multimeter, measurements must be made from both sides of the
semiconductor fuses (e.g. U1 to thyristor, V1 to thyristor and W1 to thyristor):
Faulty thyristor
−Make sure, the internal fuses are fine.
−Using the OHM function of a normal multimeter, measurements must be made from both sides of the
thyristor power controller (e.g. U1 to U2, V1 to V2 and W1 to W2).
−Normally, each measurement should show high resistance (> 1 kΩ).
−Target: find a short circuit, indicated by low resistance (< 1 Ω) (destroyed thyristor).
−If the Thyristor power controller is designed with thyristor modules, then a module consists of two
thyristors. In this case, it is sufficient to know which thyristor module has a defective thyristor because the
complete module must be replaced.
−After a thyristor module is replaced, the above-mentioned measurement should be done another time to
make sure that all faulty thyristors have been detected!
Note:
The RC / snubber circuit could also cause 0 Ωresult for a short time.
The measurement, showing less resistance than 1 Ωshould be made a second time with test leads applied to
the terminals with opposite polarity; if this measurement shows the same result, one or two thyristors located
in that path are faulty; they need to be replaced.
Fault Tracing Thyristors
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Handling the Semiconductors
General Instruction how to handle semiconductors
Thyristor modules, busbars and fuses have to be mounted with the correct torque using a torque screwdriver
or torque wrench.
Always mark suspected damaged components clearly after removing them from the circuit, to avoid confusion
with "good" components.
When removing a damaged semiconductor, write down how and where it was installed (direction, location,
connected gate leads).
Check that the new and old components have the same type designation or that the new component can
replace the old one. A semiconductor can be replaced by different compatible semiconductor according to the
codes in the manufacturers' table.
Semiconductor components are high-precision products. All unnecessary used tools and objects might
damage the easily dented and scratched surfaces of the semiconductors.
1. Keep new semiconductors as long as possible in their original packages.
2. Use protective gloves if possible.
3. Clean work area and hands frequently.
4. Use good illumination.
Handling the Semiconductors
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Exchange thyristors sizes T1 … T4
Installation of thyristor modules in thyristor power controllers size T1 …
T4 (20 A ... 740 A)
All DCT880 size T1 … T4 are equipped with thyristor modules. In order to keep the operating temperature of
the semiconductor module low, the joint between the heat sink and the module should have a good heat
conducting ability. The electrical conductivity of the connectors must also be good. For this reason, the
following instructions must be observed with particular care.
Required tools
Special tools or material needed in addition to standard tools for the exchange of thyristor modules:
−Torx screwdrivers:
TX10, TX20, TX25
−Torque spanner:
Mounting torques for the thyristor modules to heat sink and
electrical connections see table Nominal mounting torque for
thyristor modules.
−Torque spanner for electrical
connections:
13 Nm (M8)
25 Nm (M10)
50 Nm (M12)
−Screws are metric type; use
appropriate nuts.
−Tissue paper.
−Solvent (e.g. ethanol).
−Thermal joint compound (grease):
Type Berulub FZ1 E3
Manufacturer: Carl Bechem GmbH, 58089 Hagen
ABB Service: GHSN 390 011 P 0051
or
−Thermal joint compound:
Type WLPF 20 (10 ml)
ABB Service: GHSN 390 011 P 10
Before the work is started, disconnect the thyristor power controller completely from
the power supply, then check the voltage free condition and make sure, everything is
located in an electrical and mechanical safe condition!
Find faulty thyristor modules
See Fault Tracing Thyristors of this publication.
Exchange thyristors sizes T1 … T4
3ADW000449R0101 DCT880 Service Manual e a