Thursday, December 26, 2013
Thursday, December 19, 2013
Monday, December 9, 2013
Circuit breaker accessories - Service releases
Shunt opening release
This allows circuit-breaker opening by
means of an electric command. Release
operation is guaranteed for a voltage
between 70% and 110% of the rated
power supply voltage Un, both in AC and
in DC. It is always fitted with an auxiliary
limit contact.
Under voltage release
This opens the circuit-breaker due to a
power supply failure to the release, or
voltage drops to minimum values of 0.7
x Un with a trip range from 0.7 to 0.35 x Un.
After tripping, the circuit-breaker can be
closed again, starting with a voltage
higher than 0.85 x Un. With the undervoltage
release de-energised, neither
circuit-breaker nor main contact closure
is possible.
Time-delayed undervoltage release
The undervoltage release can be combined
with an external electronic power
supply time-delay device, which allows
circuit-breaker opening to be delayed in
the case of a power cut to the release
itself, according to fixed time-delays of
0.5-1-2-3 [s], so as to avoid unwarranted
trips caused by temporary malfunctions.
It is available for the SACE S3, S4, S5,
S6, and S7 circuit-breakers with power
supply voltages at 110-220 V (50-60 Hz)
only coupled with an undervoltage release
at 310 V DC.
Shunt closing release
This allows circuit-breaker closure by
means of an electric command. Operation
of the release is guaranteed for a
voltage between 80% and 110% of the
rated power supply voltage Un, both in
AC and in DC.
ABB SASE
Friday, November 29, 2013
IEC standards
IEC 60038 Standard voltages
IEC 60076-2 Power transformers - Temperature rise
IEC 60076-3 Power transformers - Insulation levels, dielectric tests and external clearances in air
IEC 60076-5 Power transformers - Ability to withstand short-circuit
IEC 60076-10 Power transformers - Determination of sound levels
IEC 60146 Semiconductor convertors - General requirements and line commutated convertors
IEC 60255 Electrical relays
IEC 60265-1 High-voltage switches - High-voltage switches for rated voltages above 1 kV and less than 52 kV
IEC 60269-1 Low-voltage fuses - General requirements
IEC 60269-2 Low-voltage fuses - Supplementary requirements for fuses for use by unskilled persons (fuses mainly for household and similar applications)
IEC 60282-1 High-voltage fuses - Current-limiting fuses
IEC 60287-1-1 Electric cables - Calculation of the current rating - Current rating equations (100% load factor) and calculation of losses - General
IEC 60364 Electrical installations of buildings
IEC 60364-1 Electrical installations of buildings - Fundamental principles
IEC 60364-4-41 Electrical installations of buildings - Protection for safety - Protection against electric shock
IEC 60364-4-42 Electrical installations of buildings - Protection for safety - Protection against thermal effects
IEC 60364-4-43 Electrical installations of buildings - Protection for safety - Protection against overcurrent
IEC 60364-4-44 Electrical installations of buildings - Protection for safety - Protection against electromagnetic and voltage disrurbance
IEC 60364-5-51 Electrical installations of buildings - Selection and erection of electrical equipment - Common rules
IEC 60364-5-52 Electrical installations of buildings - Selection and erection of electrical equipment - Wiring systems
IEC 60364-5-53 Electrical installations of buildings - Selection and erection of electrical equipment - Isolation, switching and control
IEC 60364-5-54 Electrical installations of buildings - Selection and erection of electrical equipment - Earthing arrangements
IEC 60364-5-55 Electrical installations of buildings - Selection and erection of electrical equipment - Other equipments
IEC 60364-6-61 Electrical installations of buildings - Verification and testing - Initial verification
IEC 60364-7-701 Electrical installations of buildings - Requirements for special installations or locations - Locations containing a bath tub or shower basin
IEC 60364-7-702 Electrical installations of buildings - Requirements for special installations or locations - Swimming pools and other basins
IEC 60364-7-703 Electrical installations of buildings - Requirements for special installations or locations - Locations containing sauna heaters
IEC 60364-7-704 Electrical installations of buildings - Requirements for special installations or locations - Construction and demolition site installations
IEC 60364-7-705 Electrical installations of buildings - Requirements for special installations or locations - Electrical installations of agricultural and horticultural premises
IEC 60364-7-706 Electrical installations of buildings - Requirements for special installations or locations - Restrictive conducting locations
IEC 60364-7-707 Electrical installations of buildings - Requirements for special installations or locations - Earthing requirements for the installation of data processing equipment
IEC 60364-7-708 Electrical installations of buildings - Requirements for special installations or locations - Electrical installations in caravan parks and caravans
IEC 60364-7-709 Electrical installations of buildings - Requirements for special installations or locations - Marinas and pleasure craft
IEC 60364-7-710 Electrical installations of buildings - Requirements for special installations or locations - Medical locations
IEC 60364-7-711 Electrical installations of buildings - Requirements for special installations or locations - Exhibitions, shows and stands
IEC 60364-7-712 Electrical installations of buildings - Requirements for special installations or locations - Solar photovoltaic (PV) power supply systems
IEC 60364-7-713 Electrical installations of buildings - Requirements for special installations or locations - Furniture
IEC 60364-7-714 Electrical installations of buildings - Requirements for special installations or locations - External lighting installations
IEC 60364-7-715 Electrical installations of buildings - Requirements for special installations or locations - Extra-low-voltage lighting installations
IEC 60364-7-717 Electrical installations of buildings - Requirements for special installations or locations - Mobile or transportable units
IEC 60364-7-740 Electrical installations of buildings - Requirements for special installations or locations - Temporary electrical installations for structures, amusement devices and booths at fairgrounds, amusement parks and circuses
IEC 60427 High-voltage alternating current circuit-breakers
IEC 60439-1 Low-voltage switchgear and controlgear assemblies - Type-tested and partially type-tested assemblies
IEC 60439-2 Low-voltage switchgear and controlgear assemblies - Particular requirements for busbar trunking systems (busways)
IEC 60439-3 Low-voltage switchgear and controlgear assemblies - Particular requirements for low-voltage switchgear and controlgear assemblies intended to
be installed in places where unskilled persons have access for their use - Distribution boards
IEC 60439-4 Low-voltage switchgear and controlgear assemblies - Particular requirements for assemblies for construction sites (ACS)
IEC 60446 Basic and safety principles for man-machine interface, marking and identification - Identification of conductors by colours or numerals
IEC 60439-5 Low-voltage switchgear and controlgear assemblies - Particular requirements for assemblies intended to be installed outdoors in public places - Cable distribution cabinets (CDCs)
IEC 60479-1 Effects of current on human beings and livestock - General aspects
IEC 60479-2 Effects of current on human beings and livestock - Special aspects
IEC 60479-3 Effects of current on human beings and livestock - Effects of currents passing through the body of livestock IEC 60529 Degrees of protection provided by enclosures (IP code)
IEC 60644 Spécification for high-voltage fuse-links for motor circuit applications
IEC 60664 Insulation coordination for equipment within low-voltage systems
IEC 60715 Dimensions of low-voltage switchgear and controlgear. Standardized mounting on rails for mechanical support of electrical devices in switchgear and controlgear installations.
IEC 60724 Short-circuit temperature limits of electric cables with rated voltages of 1 kV (Um = 1.2 kV) and 3 kV (Um = 3.6 kV)
IEC 60755 General requirements for residual current operated protective devices
IEC 60787 Application guide for the selection of fuse-links of high-voltage fuses for transformer circuit application
IEC 60831 Shunt power capacitors of the self-healing type for AC systems having a rated voltage up to and including 1000 V - General - Performance, testing and rating - Safety requirements - Guide for installation and operation
IEC 60947-1 Low-voltage switchgear and controlgear - General rules
IEC 60947-2 Low-voltage switchgear and controlgear - Circuit-breakers
IEC 60947-3 Low-voltage switchgear and controlgear - Switches, disconnectors, switch-disconnectors and fuse-combination units
IEC 60947-4-1 Low-voltage switchgear and controlgear - Contactors and motor-starters - Electromechanical contactors and motor-starters
IEC 60947-6-1 Low-voltage switchgear and controlgear - Multiple function equipment - Automatic transfer switching equipment
IEC 61000 Electromagnetic compatibility (EMC)
IEC 61140 Protection against electric shocks - common aspects for installation and equipment
IEC 61557-1 Electrical safety in low-voltage distribution systems up to 1000 V AC and 1500 V DC - Equipment for testing, measuring or monitoring of protective measures - General requirements
IEC 61557-8 Electrical safety in low-voltage distribution systems up to 1000 V AC and 1500 V DC - Equipment for testing, measuring or monitoring of protective measures
IEC 61557-9 Electrical safety in low-voltage distribution systems up to 1000 V AC and 1500 V DC - Equipment for insulation fault location in IT systems
IEC 61557-12 Electrical safety in low-voltage distribution systems up to 1000 V AC and 1500 V DC - Equipment for testing, measuring or monitoring of protective measures. Performance measuring and monitoring devices (PMD)
IEC 61558-2-6 Safety of power transformers, power supply units and similar - Particular requirements for safety isolating transformers for general use
IEC 62271-1 Common specifications for high-voltage switchgear and controlgear standards
IEC 62271-100 High-voltage switchgear and controlgear - High-voltage alternating-current circuit-breakers
IEC 62271-102 High-voltage switchgear and controlgear - Alternating current disconnectors and earthing switches
IEC 62271-105 High-voltage switchgear and controlgear - Alternating current switch-fuse combinations
IEC 62271-200 High-voltage switchgear and controlgear - Alternating current metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up toand including 52 kV
IEC 62271-202 High-voltage/low voltage prefabricated substations
Thursday, November 28, 2013
A hipot tester
A hipot tester is an electronic device used to verify the electrical insulation in a device or other wired assembly that could subject someone to a shock if it failed. It generally consists of:
1. A source of high voltage,
2. A current meter,
3. A switching matrix used to connect the high voltage source and the current meter to all of the contact points in a cable.
Hipot testers may also have a microcontroller and a display to automate the testing process and display the testing results.
A hipot tester can be very similar to a cable tester and often the two are combined into a single device.
In a typical wired assembly a hipot test should connect all circuits in common to ground. Then, one by one the tester will disconnect a given circuit from ground and connect that circuit to high voltage . The current that flows is monitored to verify that it is low enough.
MILLIVOLT DROP TEST
The millivolt drop test is generally associated with
testing for weld quality on the armature. It is the
best test for verifying armature weld quality.
The millivolt drop test is the ultimate electrical test
for detecting bad welds. Unfortunately, it is
difficult to make on armatures with large diameter
wire and nearly impossible to make on armatures
with small wires.
The difficulty is breaking through the insulation on
the wire as it exits the tang or commutator bar
contact. The one testing contact, usually a sharp
knife edged probe, from the KOM (Kelvin Ohm
Meter) can cut through small wires and destroy
the armature. Contact with the knife-edge probe
needs to be made on each bar. Since this is such
a difficult test to perform, it is only practical as a
laboratory test.
Various test methods have been developed over
the last twenty years that come close to making
this test. These tests make it possible to test
100% of the armatures. However, none of these
tests are as accurate or repeatable as the Millivolt
Drop Test.
ESW's weld test, which uses techniques that have
been developed over the past 20 years, comes
very close to the Millivolt Drop Test. The
repeatability and speed of the test using a
stationary armature test fixture assures that a
reliable test has been performed.
Thursday, October 24, 2013
Methods of explosion protection for electrical equipment
METHODS OF EXPLOSION PROTECTION
Method Type of Protection
Designed to prevent any means of ignition arising Ex e Increased Safety
Ex n or Ex N Non Sparking
Designed to limit the ignition energy of the circuit Ex I Intrinsic Safety
Designed to prevent the flammable mixture reaching Ex m Encapsulation
a means of ignition Ex p Pressurisation
Ex o Oil Immersion
Ex nR or Ex N Restricted Breathing
Designed to prevent any ignition from spreading Ex d Flameproof Enclosure
Ex q Powder Filling
Friday, October 18, 2013
Minimum terminal capacity for copper protective conductors (PE, PEN)
CROSS-SECTIONAL AREA OF PHASE CONDUCTORS S
MM2 |
MINIMUM CROSS-SECTIONAL AREA OF THE CORRESPONDING PROTECTIVE CONDUCTOR (PE, PEN) SPA
MM2 |
S ≤ 16
|
S
|
16 < S ≤ 35
|
16
|
35 < S ≤ 400
|
S/2
|
400 < S ≤ 800
|
200
|
800 < S
|
S/4
|
a Current in the neutral may be influenced where there are significant harmonics in the load.
| |
Minimum terminal capacity for copper protective conductors (PE, PEN)
| |
Source: IEC 61439-1 2011 Table 5
Tuesday, October 15, 2013
Friday, October 11, 2013
Guide to migration from IEC 60439 to IEC 61439 (XL3 Confugurable Assemblies IEC 60439 >>> IEC 61439)
This document only deals with distribution enclosures for advanced users (authorised persons), i.e. parts 1 and 2 of the new standard. Part 3 of standard IEC 61439 discusses DBO (Distribution Boards intended to be operated by Ordinary persons) only up to 250 A. One of the new features of this standard is that the table in appendix D (checking the design) covered laterin this document does not apply in 61439-3.
In addition in its new version, standard 61439-3 takes account of domestic normative references.
DOWNLOAD :
http://www.export.legrand.com/files/fck/pdf-EN/EXB12074_GUIDE_TABLEAUTIERS_EN.pdf
Saturday, September 14, 2013
Measurement of the insulation resistance
- the insulation resistance must be measured with amegohmmeter (external or with standalone source) at
a minimum voltage of 500 VDC
- the assembly being tested must be turned off and there must be no receiver devices connected
- all the breaking devices must be in position i (on)
- the voltage is applied between each circuit and the exposed conductive part
- it is possible to link all the poles: phases and neutral,except in tnC layout in which the pen conductor is considered to be linked to the exposed conductive part
of the assembly.Devices (measurement windings, instruments) which would not withstand the test voltage must have their supply terminals short-circuited.
the measurement conditions can influence the results obtained. measurements should not be carried out temperatures below dewpoint (condensation will
dampen the surfaces).
the insulation resistance decreases with the temperature.if repeated measurements have to be taken,the environmental conditions must be recorded. the period for which the voltage is applied also has a major influence, and measurement can be considered to consist of three sequences. at the start of measurement, the device charges the capacitor which represents the installation in relation to earth and the leakage current is at its highest.
LEGRAND POWER GUIDE
Friday, September 13, 2013
Automation Solution guide 2008 (Schneider electric)
Automation Solution guide 2008 (Schneider electric)
1 Automation solution guide 8
1.1 Introduction 10
1.2 The automation equipment 10
1.3 Automation architectures 12
1.4 Architecture definition 14
1.5 Choice of automated equipment 17
2 Electrical power supply 28
2.1 Introduction 30
2.2 Power supply to machinery 30
2.3 Standards and conventions 30
2.4 Power supply functions 32
2.5 Power supply to the control circuit 33
3 Motors and loads 36
3.1 Three phase asynchronous motors 38
3.2 Single-phase motors 42
3.3 Synchronous motors 43
3.4 Direct current motors commonly named DC motors 45
3.5 Operating asynchronous motors 47
3.6 Electric motor comparison 50
3.7 Types of loads 51
3.8 Valves and electric jacks 56
4 Starting and protection of motors 60
4.1 Asynchronous motor starting systems 62
4.2 Electrical braking of 3-phase asynchronous motors 69
4.3 Multifunction motor starter units 74
4.4 Motors protection 76
4.5 Motor losses and heating 77
4.6 Causes of faults and their effects 77
4.7 Protection functions 83
5 Motor starter units 82
5.1 Forward 84
5.2 The basic functions of motor starter units 84
5.3 Constitution and operation of contactor 95
5.4 Choosing a contactor 97
5.5 Motor starter and coordination 98
5.6 Advanced starter 103
5.7 Speed controllers 105
5.8 Structure and components of starters and electronic speed controllers 109
5.9 Power components 109
5.10 Controller – regulator for DC motors 113
5.11 AC drives for asynchronous motors 115
5.12 Voltage controller for asynchronous motors 121
5.13 Synchronous motor-speed controller 122
5.14 Stepper motor controllers 123
5.15 Additional functions of speed controllers 124
5.16 Speed controllers and energy assessment 126
5.17 Speed controllers and savings in power and maintenance 128
5.18 Choice table for motor starters 129
6 Data acquisition: detection 132
6.1 Introduction 134
6.2 Electromechanical limit switches 135
6.3 Inductive proximity detectors 136
6.4 Capacitive proximity detectors 138
6.5 Photoelectric detectors 140
6.6 Ultrasonic detectors 142
6.7 RFID -Radio Frequency IDentification-detection 144
6.8 Vision 147
6.9 Optical encoders 151
6.10 Pressure switches and vacuum switches 156
6.11 Conclusion 159
6.12 Technology selection guide 160
7 Personnal and machines safety 162
7.1 Introduction 164
7.2 Safety scope and definition 164
7.3 Industrial accidents 166
7.4 European legislation 178
7.5 Standard to be applied according design selected for the machine control 170
7.6 Standard EN/ISO 13849-1 Machinery safety - Safety-related parts 172
7.7 Standard EN 62021 Machinery safety - Functional safety 176
7.8 Certification and marking 180
7.9 Consideration of hazardous atmospheres 182
8 Human-machine interface 186
8.1 Human-machine interface setup 188
8.2 User needs specification 190
8.3 Choosing a solution 192
8.4 Discrete control and indicator units 194
8.5 Schneider Electric Discrete Control and Indicator Unit offer 197
8.6 Graphis screen display and terminal 198
8.7 Industrial and supervision PCs 200
8.8 The human/machine dialogue and supervision software 201
8.9 Control panels incorporated in the products 203
8.10 Conclusion 204
9 Industrial networks 206
9.1 Introduction 208
9.2 History 208
9.3 Market requirements and solutions 209
9.4 Network technologies 211
9.5 Networks recommended by Schneider Electric 213
9.6 Ethernet TCP/IP 214
9.7 Web services and Transparent Ready 217
9.8 Canopen bus 224
9.9 Ethernet and CANopen synergy 232
9.10 AS-Interface (AS-I) Bus 232
9.11 Conclusion 239
10 Data treatment and software 240
10.1 Définition 242
10.2 Introduction 242
10.3 Programming, configuration and languages 243
10.4 Application categories 244
10.5 UAG: Application generators 258
10.6 Definition of the main abbreviations used 262
11 Equipment manufacturing 264
11.1 Equipment design 266
11.2 Choice of supplier 267
11.3 Drafting diagrams and programs 268
11.4 Programming methodology 270
11.5 Choice of technology 271
11.6 Equipment design 272
11.7 Building an equipment 273
11.8 Mounting 276
11.9 Device fitting tools 277
11.10 Platform tests 278
11.11 Equipment commissioning 281
11.12 Equipment maintenance 283
12 Eco-design 286
12.1 Foreword 288
12.2 Concepts and main directives 289
12.3 Standards 290
12.4 Eco-design 291
12.5 Lifecycle 291
12.6 Main rules of eco-design 292
12.7 Conclusion 295
12.8 Applications 295
M Memorandum 298
M.1 Quantities and units of measurement 300
M.2 Average full-load currents of asynchronous squirrel cage motors 301
M.3 Electrical formulae 302
M.4 Calculation of starting resistances 304
M.5 Mechanical formulae 305
M.6 Fundamental formulae 306
M.7 Neutral connections 307
M.8 Driving machines 308
M.9 Conversion tables for standard units 310
7
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Wednesday, September 4, 2013
Electrical codes
Electrical codes are sets of rules established by governing bodies which state:
• Type of equipment to be used in a given situation
• Appropriate use
• Installation procedures,
including how and where it should be installed
Codes usually carry mandatory compliance, and can apply nationally or to a
more limited area, such as a single local municipality. In any case, such codes can
be used to facilitate the successful installation of equipment, or stop it dead in its
tracks. Codes are powerful, and there must be a keen awareness of the various
codes and their applications.
One of the best known set of codes is the NEC (National Electrical Code), which
works in conjunction with UL requirements. The NEC is a set of electrical installation
standards published by the National Fire Protection Agency (NFPA). The
NEC is the most widely adopted electrical code in the United States and regulates
all electrical equipment used in power distribution systems, from the source to private
residences, and even to the configuration of the circuits within homes.
As you learn about different types of electrical equipment, you will become very
aware of the standards and codes that are most relevant to that particular type of
equipment. For now, just be aware of their existence and importance.
Here is a list of the most common standards and codes (but it is far from all-inclusive):
• ANSI (American National Standards Institute)
• BSI (British Standards Association)
• CE Mark (Certified European Mark)
• CEC (Canadian Electric Code)
• CSA (Canadian Standards Association)
• IEC (International Electrotechnical Commission)
• IEEE (Institute of Electrical and Electronic Engineers)
• ISO (International Standards Organization)
• NEC (National Electrical Code)
• NEMA (National Electrical Manufacturers Association)
• UL (Underwriters Laboratories, Inc.)
EATON
Tuesday, September 3, 2013
Wednesday, August 28, 2013
Basics of Circuit Breakers (Rockwell Automation)
Basics of Circuit Breakers
Content:
1. Design, function and types of
circuit breakers 1.1
1.1. Summary 1.1
1.2. Types of switches 1.2
1.2.1. Manual motor starter and protector or
circuit breaker with motor protective characteristics 1.2
1.2.2. Circuit breaker 1.2
1.2.3. Load break switch 1.6
1.2.4. Disconnector 1.6
1.2.5. Main switch 1.7
1.2.6. Emergency OFF-switch 1.8
1.2.7. Summary: Circuit breaker as load break switch 1.8
1.3. Design of a circuit breaker 1.9
1.3.1. The current path of the circuit breaker 1.9
1.3.2. Thermal overload release 1.10
1.3.3. Electromagnetic overcurrent release 1.10
1.3.4. Main contact system 1.12
1.3.5. Auxiliary contacts 1.15
1.3.6. Operating mechanism 1.15
1.4. Functions of a circuit breaker 1.15
1.4.1. Interrupting short-circuit current 1.16
1.4.2. Reliable protection of motors 1.17
1.4.3. Protection of leads and its optimum utilisation 1.18
1.4.4. Protection of installations 1.19
1.4.5. Integration in the control circuit 1.19
1.4.6. Switching under normal service conditions 1.20
1.4.7. Disconnecting function 1.20
1.4.8. Locking out with a padlock 1.20
2. Circuit breaker technology 2.1
2.1. Summary 2.1
2.2. Short-circuit current in supply systems 2.2
2.2.1. Types of short-circuit 2.2
2.2.2. The peak value of the short-circuit current 2.3
2.2.3. Calculation of the short-circuit current close to the transformer 2.4
2.2.4. Calculation of the short-circuit current in radial supply systems 2.7
2.2.5. Dynamic stress on the connecting leads
in the case of a short-circuit 2.16
2.3. Short-circuit protection 2.18
2.3.1. The principle of current limitation 2.18
2.3.2. Breaking capacity 2.26
2.3.3. Electrical life (durability) of
circuit breakers 2.26
2.4. Short-circuit co-ordination 2.28
2.4.1. Definitions in accordance with
the IEC 947-4-1 2.28
2.4.2. Conclusions drawn from the
definitions for the user 2.28
2.4.3. Physical significance of the short-circuit
co-ordination 2.30
2.4.4. Requirements of a circuit breaker for a simple
co-ordination of type "2" 2.33
3. Fields of application of circuit breakers 3.1
3.1. General procedure for the selection of
correctly rated circuit breakers 3.1
3.2. Circuit breakers for motor protection 3.2
3.2.1. Protection of motors with direct-on-line starting 3.3
3.2.2. Protection of motors with star-delta starting 3.4
3.2.3. Protection during heavy-duty starting 3.8
3.2.4. Circuit breaker with a motor protective
device connected downstream 3.8
3.2.5. Protection of motors in explosive environments 3.12
3.2.6. Protection of motors with phase controlled
starting (soft starter) 3.13
3.2.7. Protection of frequency controlled motors
(frequency converter) 3.14
3.3. Circuit breakers for the protection of
connecting leads and for group protection 3.16
3.3.1. Protection of the connecting leads 3.16
3.3.2. Group protection 3.16
3.4. Circuit breakers for capacitors 3.17
3.5. Circuit breakers for transformers 3.18
3.5.1. Protection of transformer: primary side 3.18
3.5.2. Protection of transformer: secondary side 3.18
3.6. Circuit breakers for generators 3.18
3.7. Circuit breakers for special supply frequencies 3.19
3.7.1. Breaking capacity at frequencies below 50/60Hz 3.19
3.7.2. Breaking capacity at frequencies above 50/60Hz 3.20
3.8. Interruption of direct current 3.20
3.9. Breaking capacity at higher supply voltages 3.21
3.10. Selectivity (discrimination) 3.21
3.10.1. Selectivity between circuit breakers 3.21
3.10.2. Selectivity between circuit breaker and fuse 3.24
3.10.3. Selectivity between fuses 3.25
4. Arguments in favor of the circuit breaker 4.1
4.1. Summary 4.1
4.2. Comparison of the functions:
circuit breaker / fuse 4.2
4.2.1. Time-current characteristics 4.2
4.2.2. Comparison of Joule-integrals 4.3
4.2.3. Comparison of the ultimative tripping current 4.4
4.2.4. Table of comparison 4.4
4.3. Arguments in favour of the circuit breaker 4.6
4.3.1. Prevention of accidents with the help of
circuit breakers 4.6
4.3.2. Ready to be switched on again without delay 4.8
4.3.3. All pole interruption 4.9
4.3.4. No ageing 4.9
4.3.5. Reduction of the conductor cross-section 4.10
4.3.6. Simplified planning of installations 4.14
4.3.7. Reduction of costs of installations and
optional costs 4.14
iii
Circuit
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Tuesday, August 13, 2013
Friday, August 2, 2013
Electrical Panel Board Final Inspection and Testing
Final Inspection and Testing
QCI Carry out ROUTINE TESTS as per IEC 60439-1 standards. The following minimum tests
must be performed:
Visual inspection test – Checking of the complete switchboard in accordance with IEC
60439-1 standards and approved drawings. Checking of Integrity of Wiring, Tightness of all
joints, and Torque test on all bus connections, etc.
Di-electric Test – Done using a MEGGER (verification of Insulation resistances between
phases, phase-neutral, phase-earth and neutral-earth). This test is also verified by a HIPOT
test using a 2.5kV test between phases for 1min.
Mass Continuity Test – To check if there is proper earth continuity from end of the
switchboard to the other. This test can be checked
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