ROOTECH ACCURA 7500 User manual

Notice
Accura 7500 User Guide
Page 2
ⓒ2006 Rootech Inc. All Rights Reserved
Notice
Symbols
Caution
Indicates the presence of dangerous voltage which can cause severe injury or death if
proper precautions are not followed.
Caution
Alerts users of the presence of hazards which can cause injury to persons, property
damage or damage to the device if proper precautions are not followed.
Note
Indicates major instructions for the installation, operation, and maintenance of the
product.
Indicates alternative voltage or current.
Indicates direct voltage or current.
Installation Considerations
The installation, operation, and maintenance of the product should be performed only by qualified,
competent personnel that have received appropriate training for high voltage and current devices.
Caution
If hazardous voltages are mishandled while installing and operating the product in the field, it can
cause serious injury or death.
◼During normal operation of the product, hazardous voltages are present on the terminals that
connect PTs/CTs, digital inputs, power, and external I/O circuits. The PT/CT secondary can produce
lethal voltage or current caused by the energy of the primary.
◼Standard safety precautions should be followed during the installation and maintenance of the
product, including removing PT fuses and shorting CT secondaries.
◼Install the product in enclosures or a similar cabinet to prevent access to the terminal strips of the
product after wiring.

Accura 7500 User Guide
Notice
ⓒ2006 Rootech Inc. All Rights Reserved
Page 3
Caution
Observe the following instructions, or it may cause permanent damage to the product.
◼Do not apply voltages and currents that exceed the input ratings of the PT and CT to the product.
◼Using the device for other purposes not specified by the manufacturer can cause severe damage to
the product.
◼Connect the chassis ground terminal of the product to the earth ground to protect the device
from noise and surge. Failure to properly connect the chassis ground will void the warranty of the
product.
◼The maximum screw tightening torque is as follows.
-Barrier-type voltage/current input port: 1.35 N∙m (14 kgf∙cm = 1.00 lbf∙ft) max.
-Barrier-type digital input and output ports: 0.90 N∙m (9 kgf∙cm = 0.66 lbf∙ft) max.
About the Manual
Rootech, Inc. reserves the right to make changes in the product specifications shown in this User Guide
without prior notice. We recommend that customers should obtain the latest information on product
specifications and the manual before making orders.
In the absence of written agreements, Rootech, Inc. assumes no liability for applications assistance,
customer’s system design, or infringement of patents or copyrights induced by third parties arising from
the use of the products described herein.
We endeavor to provide accurate information in the document. However, we are not responsible for any
errors which may appear here and reserves the right to make changes without prior notice.
Limitation of Liability
Where applicable law allows and does not prohibit or restrict such limitation, Rootech, Inc’s liability for
this product shall be limited to the amount actually paid by customers for the product.

Warranty
Accura 7500 User Guide
Page 4
ⓒ2006 Rootech Inc. All Rights Reserved
Warranty
Rootech Inc. provides warrants for two years from the product receipt date only to the original purchaser
of the products and software that are sold or licensed by the company.
To obtain warranty service, the purchased products should be free from serious defects in material and
workmanship.
The software is provided in an up-to-date version, thus we do not offer any warranty for the software
product.
In order to make a product claim under the warranties described above, the original purchaser should
immediately contact Rootech headquarters. Upon receiving claims, Rootech will check out the product
either at where the purchaser is or at the company after receiving the product from the customer, who is
responsible for the cost of shipping the product. After inspecting the product, we will provide repair or
replacement services for the product.
Rootech will decide at its discretion whether to repair or replace it or give a refund for the product for
when the warranty period for the product expired or issues related to the product are not applicable for
warranty terms and conditions.
Limitation of Warranty
The Warranty does not apply to uninterrupted or error-free operation of the product or cover normal
wear and tear of the product or costs caused by the removal, installation, or troubleshooting of the
customer's electrical systems.
◼Defects caused by any of the following factors are not covered under the warranty.
◼Improper use(alteration, accident, misuse, abuse) or failure to act in accordance with installation,
operation or maintenance instructions
◼Unauthorized modifications, changes or repair attempts
◼Failure to comply with applicable safety standards & regulations
◼Damages coming from when transporting or storing the product
◼Damages caused by the force majeure event, including fire, flood, earthquakes, storm damage,
overvoltage & lightning
◼If the original identification marks(trade-mark, serial number, etc.) have been defaced, altered, or
removed

Accura 7500 User Guide
Warranty
ⓒ2006 Rootech Inc. All Rights Reserved
Page 5
Rootech shall not be liable for any other claims except the claims made by customers, including the
original purchaser, his employees, agents, or contractors for any loss, damage, or expense incurred
related to the purchased product when the above warranty terms and conditions are not fulfilled.
Any technical assistance with system design provided by Rootech's personnel or representatives shall be
deemed to be a suggestion. The original purchaser is responsible for determining the feasibility of such
suggestions and should conduct tests to prove their feasibility.
It is the original purchaser’s responsibility to determine the suitability of the product and associated
documentation. The original purchaser should acknowledge that 100 % up time is not realizable because
of possible hardware or software defects. The original purchaser should recognize that such defects and
failures may cause inaccuracies or malfunctions.
No agency, corporate entity, or employee of Rootech or other companies has authority to amend,
modify or extend the terms and conditions of this warranty in any way without express written
authorization from Rootech, Inc.
Standard Compliance
Process Control Equipment
E324900
MSIP-REM-RTE-Accura7500

Revision History
Accura 7500 User Guide
Page 6
ⓒ2006 Rootech Inc. All Rights Reserved
Revision History
The following versions of Accura 7500 User Guide have been released.
Revision
Date
Description
Revision 1.0
2006. 5. 02
Initial release
Revision 1.1
2007. 3. 06
Revision
Revision 1.2
2007. 7. 01
Wiring diagram changed
Revision 1.3
2008. 12. 30
Applied from Relay Ver2.11
DI input is connected to output as DO
Revision 3.0
2010. 3. 03
OVGR, UVR, SGR multi-stage configuration possible
Revision 5.0
2010. 12. 01
Motor Protection element added
Manual revision number is same as Protection Relay Software version
For Software Version 5.0 or less, please refer to User Guide Revision 3.0.
Revision 5.1
2012. 7. 09
Table 9.2

value added
Revision 5.2
2013. 2. 27
Table 9.1 Change of K value of LI Curve and accordingly Table 9.6 Timetable
contents changed
Revision 5.3
2013. 3. 08
Cautions related to SGR MTA configuration added(page 123)
Revision 5.4
2013. 3. 15
Wiring diagram changed(page 45 –47)
Inverse time LI characteristic table error changed(page 182)
Revision 5.5
2014. 3. 17
F/W Ver. From 5.07 Motor Protection function Added explanation about
changing Ip reflection method of THR(page 28, 110, 191)
CB ON, OFF Cautions when wiring control signal(page 44, 204)
Revision 5.6
2016. 3. 22
Inverse time LI characteristic curve error correction(page 183)
Revision 5.9
2016. 10. 24
Added description of F/W Version reflecting inverse time LI characteristic
curve change(Table 9.1 Note)
Revision 6.0
2019. 5. 27
Changed the overall format
Revision 6.1
2019. 10. 10
Rated current 1 A model removed from current input specification
Revision 6.2
2022. 6.14
Modified the setup ranges of protection relay elements
Modified content on standard compliance
Modified wiring diagrams

Accura 7500 Guide
Contents
ⓒ2006 Rootech Inc. All Rights Reserved
Page 7
Contents
Chapter 1 Product Introduction .........................................................................................................................19
Overview ....................................................................................................................................................... 19
Applications ................................................................................................................................................... 20
Product Features............................................................................................................................................. 21
Chapter 2 Technical Specifications ....................................................................................................................22
Protection Relays............................................................................................................................................. 22
Measurements................................................................................................................................................ 29
Measurement Test........................................................................................................................................... 30
Device Reliability Test ...................................................................................................................................... 31
Control .......................................................................................................................................................... 32
Input & Output ............................................................................................................................................... 33
Communication ............................................................................................................................................. 34
User Interface................................................................................................................................................. 34
Additional Features......................................................................................................................................... 35
Standard Compliance..................................................................................................................................... 35
Chapter 3 Product Installation...........................................................................................................................36
Installation Conditions .................................................................................................................................... 36
Before Installation........................................................................................................................................... 36
Dimensions ............................................................................................................................................ 37
Step 1: Panel Mounting................................................................................................................................... 39
Detachment and Assembly of the Unit for Repair ...................................................................................... 41
Step 2: External Wiring ................................................................................................................................... 42
Wiring Diagram Example (3P4W with 3 PTs and 3CTs).............................................................................. 43
Wiring Diagram Example (3P3W with 3 PTs and 3 CTs)............................................................................. 44
Wiring Diagram Example (3P3W with 2 PTs and 2 CTs)............................................................................. 45
Port Layout on the Rear Panel .................................................................................................................. 46
Description of Rear Panel Ports................................................................................................................. 47
Block Diagram........................................................................................................................................ 49
Chapter 4 Meter Operation/Setup.....................................................................................................................50

Contents
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ⓒ2006 Rootech Inc. All Rights Reserved
Display Mode................................................................................................................................................. 51
Setup Mode.................................................................................................................................................... 55
Reset Mode .................................................................................................................................................... 57
System Mode.................................................................................................................................................. 58
Reactive Power Calculation ...................................................................................................................... 59
Chapter 5 Operating the Protection Relay ..........................................................................................................63
LED Indicators ................................................................................................................................................ 64
Button Control................................................................................................................................................ 65
Unlocking the Device...................................................................................................................................... 66
LCD Display and Changing Setup Values......................................................................................................... 68
Chapter 6 Protection Relay Setup and Analysis of Faults........................................................................................71
OCR Setup..................................................................................................................................................... 72
Inverse-time OCR ................................................................................................................................... 73
Instantaneous OCR................................................................................................................................. 76
NSOCR Setup ................................................................................................................................................ 77
Inverse-time NSOCR ............................................................................................................................... 78
Instantaneous NSOCR............................................................................................................................. 81
OCGR Setup .................................................................................................................................................. 82
Inverse-time OCGR................................................................................................................................. 82
Definite-time OCGR................................................................................................................................ 86
Instantaneous OCGR .............................................................................................................................. 87
OVR Setup ..................................................................................................................................................... 88
Definite-time OVR................................................................................................................................... 89
Instantaneous OVR ................................................................................................................................. 92
NSOVR Setup................................................................................................................................................. 93
Definite-time NSOVR............................................................................................................................... 94
POR Setup...................................................................................................................................................... 97
Definite-time POR ................................................................................................................................... 98
UVR Setup.................................................................................................................................................... 101
Definite-time UVR ................................................................................................................................. 102

Accura 7500 Guide
Contents
ⓒ2006 Rootech Inc. All Rights Reserved
Page 9
Etc. Setup of the UVR............................................................................................................................. 105
Motor Protection Elements Setup.................................................................................................................... 106
THR...................................................................................................................................................... 107
Lock ..................................................................................................................................................... 111
Motor Starting....................................................................................................................................... 112
Undercurrent ........................................................................................................................................ 114
OVGR Setup................................................................................................................................................. 115
Definite-time OVGR .............................................................................................................................. 116
Instantaneous OVGR............................................................................................................................. 119
SGR Setup.................................................................................................................................................... 120
Definite-time SGR ................................................................................................................................. 121
Fault Reset.................................................................................................................................................... 124
Record (Event Record) ................................................................................................................................... 124
Chapter 7 Checking the Status of Relays..........................................................................................................126
Voltage ........................................................................................................................................................ 127
Current ........................................................................................................................................................ 128
DI Status ...................................................................................................................................................... 128
DO Status .................................................................................................................................................... 129
Event Record ................................................................................................................................................ 130
CB Operation Counter.................................................................................................................................. 131
Program Version........................................................................................................................................... 131
Chapter 8 General Setup of Relay Functions.....................................................................................................132
Passcode...................................................................................................................................................... 133
Record Deletion............................................................................................................................................ 135
DIN Setup .................................................................................................................................................... 138
DO Setup..................................................................................................................................................... 141
DOs Associated with Relays........................................................................................................................... 145
DO Control.................................................................................................................................................. 149
LCD Setup.................................................................................................................................................... 151
PT Fault Detection Function ........................................................................................................................... 154
CB Fault Detection........................................................................................................................................ 157
Disabling the Protection Function................................................................................................................... 160
Date and Time Setup .................................................................................................................................... 164

Contents
Accura 7500 Guide
Page 10
ⓒ2006 Rootech Inc. All Rights Reserved
DO Associated with DI.................................................................................................................................. 166
Chapter 9 Characteristics of Protection Relays ..................................................................................................169
Inverse-time Characteristics........................................................................................................................... 169
IEC Curves ........................................................................................................................................... 169
KEPCO Curves...................................................................................................................................... 170
Characteristics of Selective Ground Relay (SGR) ............................................................................................. 182
Instantaneous and Definite-time Characteristics ............................................................................................. 183
THR Characteristic ........................................................................................................................................ 184
Motor Starting Characteristics ....................................................................................................................... 194
Chapter 10 Setup Examples ...........................................................................................................................195
Setup for Automatic Power Recovery Function................................................................................................. 195
UVR Setup ............................................................................................................................................ 195
DIN Setup............................................................................................................................................. 197
Precautions........................................................................................................................................... 198
Appendix A Wiring Examples.........................................................................................................................199
3-Phase 4-Wire ............................................................................................................................................ 199
3-Phase 3-Wire : 3 PTs & 2 CTs ..................................................................................................................... 200
3-Phase 3-Wire : Open-Delta, 2 CTs ............................................................................................................. 201
Sequence Diagram....................................................................................................................................... 202

Accura 7500 Guide
Figures
ⓒ2006 Rootech Inc. All Rights Reserved
Page 11
Figures
Figure 3.1 Accura 7500 Front................................................................................................................... 37
Figure 3.2 Accura 7500 Rear ................................................................................................................... 37
Figure 3.3 Accura 7500 Side.................................................................................................................... 38
Figure 3.4 Assembly Structure................................................................................................................... 39
Figure 3.5 Panel Assembly Method ........................................................................................................... 40
Figure 3.6 Panel Cutouts .......................................................................................................................... 40
Figure 3.7 Detachment of the Unit from the Chassis .................................................................................. 41
Figure 3.8 Wiring Diagram(3P4W with 3 PTs and 3 CTs) ............................................................................ 43
Figure 3.9 Wiring Diagram (3P3W with 3 PTs and 3 CTs) ........................................................................... 44
Figure 3.10 Wiring Diagram (3P3W with 2 PTs and 2 CTs: 3P3O) .............................................................. 45
Figure 3.11 Rear Panel Port Layout Diagram ............................................................................................. 46
Figure 3.12 Block Diagram ...................................................................................................................... 49
Figure 4.1 Front Panel for Display and Control.......................................................................................... 50
Figure 4.2 Display Group......................................................................................................................... 51
Figure 4.3 Power Signs............................................................................................................................. 60
Figure 4.4 Apparent Power Vector Diagram............................................................................................... 61
Figure 5.1 Front Panel for Display and Control.......................................................................................... 63
Figure 5.2 Passcode Input Screen.............................................................................................................. 67
Figure 5.3 Typing the Passcode ................................................................................................................. 67
Figure 5.4 Initial OCR Setup Screen .......................................................................................................... 68
Figure 5.5 Inverse-time OCR Setup Screen ................................................................................................ 69
Figure 5.6 Screen Showing the Cursor Appearing in the Row Where the Setup Item is Selected .................... 69
Figure 5.7 Screen Showing the Cursor Appearing Partially with a Numerical Set Value ................................ 69

Figures
Accura 7500 Guide
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ⓒ2006 Rootech Inc. All Rights Reserved
Figure 5.8 Screen Asking Whether to Apply Changes................................................................................. 70
Figure 5.9 Screen Notifying that Changes Have Been Made....................................................................... 70
Figure 5.10 Screen Notifying that Changes Have Been Undone ................................................................. 70
Figure 6.1 Protection Relay Part................................................................................................................. 71
Figure 6.2 Initial OCR Setup Screen .......................................................................................................... 72
Figure 6.3 Inverse-time OCR Setup Screen ................................................................................................ 73
Figure 6.4 Status Where the Cursor Appears Partially and Changes Can be Made...................................... 74
Figure 6.5 Status Where the ENTER Button Is Pressed after Changing Setup Items ....................................... 74
Figure 6.9 Instantaneous OCR Setup Screen.............................................................................................. 76
Figure 6.10 Initial NSOCR Setup Screen.................................................................................................... 77
Figure 6.11 Inverse Time NSOCR Setup Screen ......................................................................................... 78
Figure 6.12 Status Where the Cursor Appears Partially and Changes Can be Made .................................... 79
Figure 6.13 Status Where the ENTER Button Is Pressed after Changing Setup Items ..................................... 79
Figure 6.14 Screen Asking Whether to Apply Changes............................................................................... 80
Figure 6.15 Screen Notifying that Changes Have Been Made..................................................................... 80
Figure 6.16 Screen Notifying that Changes Have Been Undone ................................................................. 80
Figure 6.17 Instantaneous NSOCR Setup Screen ....................................................................................... 81
Figure 6.18 Initial OCGR Setup Screen ..................................................................................................... 82
Figure 6.19 Inverse-time OCGR Setup Screen ........................................................................................... 83
Figure 6.20 Status Where the Cursor Appears Partially and Changes Can be Made .................................... 84
Figure 6.21 Status Where the ENTER Button Is Pressed after Changing Setup Items ..................................... 84
Figure 6.22 Screen Asking Whether to Apply Changes............................................................................... 85
Figure 6.23 Screen Notifying that Changes Have Been Made..................................................................... 85
Figure 6.24 Screen Notifying that Changes Have Been Undone ................................................................. 85
Figure 6.25 Definite-time OCGR Setup Screen .......................................................................................... 86

Accura 7500 Guide
Figures
ⓒ2006 Rootech Inc. All Rights Reserved
Page 13
Figure 6.26 Instantaneous OCGR Setup Screen......................................................................................... 87
Figure 6.27 Initial OVR Setup Screen......................................................................................................... 88
Figure 6.28 Definite-time OVR Setup Screen.............................................................................................. 89
Figure 6.29 Status Where the Cursor Appears Partially and Changes Can be Made .................................... 90
Figure 6.30 Status Where the ENTER Button Is Pressed after Changing Setup Items ..................................... 90
Figure 6.31 Screen Asking Whether to Apply Changes............................................................................... 91
Figure 6.32 Screen Notifying that Changes Have Been Made..................................................................... 91
Figure 6.33 Screen Notifying that Changes Have Been Undone ................................................................. 91
Figure 6.34 Instantaneous OVR Setup Screen ............................................................................................ 92
Figure 6.35 Initial NSOVR Setup Screen .................................................................................................... 93
Figure 6.36 Definite-time NSOVR Setup Screen ......................................................................................... 94
Figure 6.37 Status Where the Cursor Appears Partially and Changes Can be Made .................................... 95
Figure 6.38 Status Where the ENTER Button Is Pressed after Changing Setup Items ..................................... 95
Figure 6.39 Screen Asking Whether to Apply Changes............................................................................... 96
Figure 6.40 Screen Notifying that Changes Have Been Made..................................................................... 96
Figure 6.41 Screen Notifying that Changes Have Been Undone ................................................................. 96
Figure 6.42 Initial POR Setup Screen......................................................................................................... 97
Figure 6.43 Definite-time POR Setup Screen.............................................................................................. 98
Figure 6.44 Status Where the Cursor Appears Partially and Changes Can be Made.................................... 99
Figure 6.45 Status Where the ENTER Button Is Pressed after Changing Setup Items ..................................... 99
Figure 6.46 Screen Asking Whether to Apply Changes............................................................................. 100
Figure 6.47 Screen Notifying that Changes Have Been Made................................................................... 100
Figure 6.48 Screen Notifying that Changes Have Been Undone ............................................................... 100
Figure 6.49 Initial UVR Setup Screen....................................................................................................... 101
Figure 6.50 Definite-time UVR setup screen............................................................................................. 102

Figures
Accura 7500 Guide
Page 14
ⓒ2006 Rootech Inc. All Rights Reserved
Figure 6.51 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 103
Figure 6.52 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 103
Figure 6.53 Screen Asking Whether to Apply Changes............................................................................. 103
Figure 6.54 Screen Notifying that Changes Have Been Made................................................................... 104
Figure 6.55 Screen Notifying that Changes Have Been Undone ............................................................... 104
Figure 6.56 Etc. Settings Screen .............................................................................................................. 105
Figure 6.57 Initial Setup Screen of MOTOR Protection Elements................................................................ 106
Figure 6.58 Initial THR Setup Screen ....................................................................................................... 107
Figure 6.59 Screen Displaying the Last Setup Item of THR ........................................................................ 107
Figure 6.60 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 108
Figure 6.61 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 109
Figure 6.62 LCD Screen Displaying Content in the Fifth Row .................................................................... 109
Figure 6.63 Screen Asking Whether to Apply Changes............................................................................. 110
Figure 6.64 Screen Notifying that Changes Have Been Made................................................................... 110
Figure 6.65 Screen Notifying that Changes Have Been Undone ............................................................... 110
Figure 6.66 Initial Lock Setup Screen....................................................................................................... 111
Figure 6.67 Initial Setup Screen of Motor Starting Protection Elements ...................................................... 112
Figure 6.68 Initial Setup Screen of Undercurrent Protection Element ......................................................... 114
Figure 6.69 Initial OVGR Setup Screen.................................................................................................... 115
Figure 6.70 Definite-time OVGR Setup Screen......................................................................................... 116
Figure 6.71 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 117
Figure 6.72 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 117
Figure 6.73 Screen Asking Whether to Apply Changes............................................................................. 118
Figure 6.74 Screen Notifying that Changes Have Been Made................................................................... 118
Figure 6.75 Screen Notifying that Changes Have Been Undone ............................................................... 118

Accura 7500 Guide
Figures
ⓒ2006 Rootech Inc. All Rights Reserved
Page 15
Figure 6.76 Instantaneous OVGR Setup Screen ....................................................................................... 119
Figure 6.77 Initial SGR Setup Screen....................................................................................................... 120
Figure 6.78 Definite-time SGR Setup Screen............................................................................................ 121
Figure 6.79 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 122
Figure 6.80 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 122
Figure 6.81 Screen Asking Whether to Apply Changes............................................................................. 123
Figure 6.82 Screen Notifying that Changes Have Been Made................................................................... 123
Figure 6.83 Screen Notifying that Changes Have Been Undone ............................................................... 123
Figure 6.84 Initial Event Record Screen ................................................................................................... 124
Figure 6.85 Screen with Event Record Number Decreased by 1 Compared to the Previous Screen.............. 125
Figure 6.86 Screen Appearing after Pressing the ENTER Button On the Event Record Screen ...................... 125
Figure 6.87 Screen Appearing when Using the 󰵍Button On the Event Record Screen ............................... 125
Figure 7.1 Initial Status Screen................................................................................................................ 126
Figure 7.2 Voltage Display Screen........................................................................................................... 127
Figure 7.3 Current Display Screen .......................................................................................................... 128
Figure 7.4 DI Status Display Screen......................................................................................................... 129
Figure 7.5 DO Status Display Screen....................................................................................................... 129
Figure 7.6 Event Record Display Screen................................................................................................... 130
Figure 7.7 CB Operation Counter Display Screen.................................................................................... 131
Figure 7.8 Program Version Display Screen ............................................................................................. 131
Figure 8.1 Initial Setup Screen ................................................................................................................ 132
Figure 8.2 Passcode Setup Screen........................................................................................................... 133
Figure 8.3 Screen Asking Whether to Change the Passcode With the Cursor Appearing Partially ................ 133
Figure 8.4 Passcode Entry Screen Showing the Cursor Appearing Partially................................................. 133
Figure 8.5 Passcode Mismatch Message Screen....................................................................................... 134

Figures
Accura 7500 Guide
Page 16
ⓒ2006 Rootech Inc. All Rights Reserved
Figure 8.6 Passcode Change Completed! Message Screen....................................................................... 134
Figure 8.7 Record Deletion Menu Screen................................................................................................. 135
Figure 8.8 Status Where Resetting Menu Items Can Be Performed ............................................................ 136
Figure 8.9 Status Where the ENTER Button is Pressed after Selecting the Item to Delete.............................. 136
Figure 8.10 Screen Asking Whether to Apply Setup Data.......................................................................... 137
Figure 8.11 Screen Notifying that Changes Have Been Made................................................................... 137
Figure 8.12 Screen Notifying that Changes Have Been Undone ............................................................... 137
Figure 8.13 DIN Setup Screen ................................................................................................................ 138
Figure 8.14 Status Where Changes Can be Made with the Cursor Appearing Partially............................... 139
Figure 8.15 Status Where the ENTER key is Pressed After Changing Setup Items........................................ 140
Figure 8.16 Screen Asking Whether to Apply Changes............................................................................. 140
Figure 8.17 Screen Notifying that Changes Have Been Made................................................................... 140
Figure 8.18 Screen Notifying that Changes Have Been Undone ............................................................... 141
Figure 8.19 DO Setup Screen................................................................................................................. 141
Figure 8.20 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 143
Figure 8.21 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 143
Figure 8.22 Screen Asking Whether to Apply Changes............................................................................. 144
Figure 8.23 Screen Notifying that Changes Have Been Made................................................................... 144
Figure 8.24 Screen Notifying that Changes Have Been Undone ............................................................... 144
Figure 8.25 Setup Screen for DOs Associated with Relays ........................................................................ 145
Figure 8.26 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 147
Figure 8.27 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 147
Figure 8.28 Screen Asking Whether to Apply Changes............................................................................. 148
Figure 8.29 Screen Notifying that Changes Have Been Made................................................................... 148
Figure 8.30 Screen Notifying that Changes Have Been Undone ............................................................... 148

Accura 7500 Guide
Figures
ⓒ2006 Rootech Inc. All Rights Reserved
Page 17
Figure 8.31 DO Control Menu Screen..................................................................................................... 149
Figure 8.32 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 150
Figure 8.33 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 151
Figure 8.34 LCD Setup Screen................................................................................................................ 151
Figure 8.35 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 152
Figure 8.36 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 152
Figure 8.37 Screen Asking Whether to Apply Changes............................................................................. 153
Figure 8.38 Screen Notifying that Changes Have Been Made................................................................... 153
Figure 8.39 Screen Notifying that Changes Have Been Undone ............................................................... 153
Figure 8.40 PT Fault Detection Function Setup Screen .............................................................................. 154
Figure 8.41 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 155
Figure 8.42 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 155
Figure 8.43 Screen Asking Whether to Apply Changes............................................................................. 156
Figure 8.44 Screen Notifying that Changes Have Been Made................................................................... 156
Figure 8.45 Screen Notifying that Changes Have Been Undone ............................................................... 156
Figure 8.46 CB Fault Detection Function Setup Screen ............................................................................. 157
Figure 8.47 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 158
Figure 8.48 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 158
Figure 8.49 Screen Asking Whether to Apply Changes............................................................................. 159
Figure 8.50 Screen Notifying that Changes Have Been Made................................................................... 159
Figure 8.51 Screen Notifying that Changes Have Been Undone ............................................................... 159
Figure 8.52 Protection Function Setup Item.............................................................................................. 160
Figure 8.53 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 162
Figure 8.54 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 162
Figure 8.55 Screen Asking Whether to Apply Changes............................................................................. 163

Figures
Accura 7500 Guide
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ⓒ2006 Rootech Inc. All Rights Reserved
Figure 8.56 Screen Notifying that Changes Have Been Made................................................................... 163
Figure 8.57 Screen Notifying that Changes Have Been Undone ............................................................... 163
Figure 8.58 Date Setup Screen ............................................................................................................... 164
Figure 8.59 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 165
Figure 8.60 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 165
Figure 8.61 Setup Screen for the DO Associated with the DI..................................................................... 166
Figure 8.62 Status Where the Cursor Appears Partially and Changes Can be Made .................................. 167
Figure 8.63 Status Where the ENTER Button Is Pressed after Changing Setup Items ................................... 167
Figure 8.64 Screen Asking Whether to Apply Changes............................................................................. 168
Figure 8.65 Screen Notifying that Changes Have Been Made................................................................... 168
Figure 8.66 Screen Notifying that Changes Have Been Undone ............................................................... 168
Figure 9.1 IEC Curve A .......................................................................................................................... 171
Figure 9.2 IEC Curve B........................................................................................................................... 173
Figure 9.3 IEC Curve C .......................................................................................................................... 175
Figure 9.4 IEC Curve LI .......................................................................................................................... 177
Figure 9.5 KEPCO Normal Inverse.......................................................................................................... 179
Figure 9.6 KEPCO Very Inverse............................................................................................................... 181
Figure 9.7 Operating Characteristic of the SGR ....................................................................................... 183
Figure 9.8 THR Thermal Curve ............................................................................................................... 185
Figure 10.1 Initial UVR Setup Screen ....................................................................................................... 195
Figure 10.2 Definite-time UVR Setup Screen ............................................................................................ 196
Figure 10.3 DIN Setup Screen ................................................................................................................ 197
Figure 10.4 Input Setup Screen for CB Operation In the Event of Power Recovery ...................................... 197

Accura 7500 User Guide
Chapter 1 Product Introduction
ⓒ2006 Rootech Inc. All Rights Reserved
Page 19
Chapter 1 Product Introduction
Overview
Protection Relay Supporting Essential Relay Elements
Accura 7500 provides protection for both extra-high voltage feeders and motors. With separate
operation keys for individual relay functions, Accura 7500 allows for easy device operation and setup.
Multifunctional Device with Metering and Protection Functions
Accura 7500 provides the functions of not only power meters, but also protection relays. However, these
functions are provided separately from each other in terms of the device’s design and structure. The
metering functions are available on the left side of the device while the protective relay functions are
available on the right side. Separate operation keys are available in the two sections. Thus, it allows for
easy and safe device controls.
Easy Controls
The metering functions of Accura 7500 can be controlled in the same way as those of other Accura
meters such as Accura 3300/3500. Thus, it makes it possible for users to control it with ease. Data on
protection relay functions are displayed on the LCD screen in Korean so that users can easily check
related data and control the functions. The product comes with a separate selection key for each relay
element. Thus, users can get easy access to setup menus with a single press of each key.
Proven Safety and Reliability
Accura 7500 features redundant DSPs(Digital Signal Processors) for the metering and protection
functions in order to effectively monitor device malfunctions. It meets the requirements of IEC 60255-22
and IEC 61010 standards to ensure the reliability and safety of the product.
Accurate Measurements and Various Power Quality Parameters Available
Accura 7500 performs highly accurate voltage/current measurements with an accuracy of ±0.2 % of
reading. It meets IEC 62053-22 Class 0.5S standards for power/energy measurements. It also provides a
variety of data for power quality analysis, including voltage/current THD, harmonics, and K-factor.

Chapter 1 Product Introduction
Accura 7500 User Guide
Page 20
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Applications
Specially Designed for Use in Extra-high Voltage Panels
Accura 7500 performs general feeder and motor protection for high-voltage consumers.
Metering Function Available with a Protection Relay
Accura 7500 is equipped with the functions of both power meters and protection relays. However, these
functions are provided separately in terms of the device’s design and structure. Metering functions are
available on the left side of the device while protection relay functions are available on the right side of
the device. It allows for convenient device controls and also helps users to easily use the metering
function of a protection relay without worrying about the maloperation of the device.
Accurate Measurements
Accura 7500 is equipped with CTs for protection relays and CTs for measurements for enhanced
measurement accuracy. This helps address problems with reduced accuracy arising from using only one
CT with the existing protection relays for protection and measurement purposes.
True RMS Measurements
Nonlinear loads mainly used in the field, including rectifiers, electronic devices, and electric furnaces
cause harmonics that involve severe voltage and current waveform distortion. Accura 7500 performs true
RMS measurements for voltage and current waveforms distorted due to harmonics.
Power Quality Analysis
Accura 7500 allows for power quality analysis by providing data, including voltage/current THD and K-
factor. It enables analysis of harmonics up to the 31st order.
Highly Reliable Energy Management
Energy management includes monitoring energy consumption, managing energy costs and energy
demand, replacing energy facilities, and performing energy planning. Measurement accuracy is a key
factor that determines the reliability of energy management systems. Accura 7500 provides highly
accurate measurements of voltage and current (±0.2% of reading) and meets IEC 62053-22 Class 0.5S
standards for power and energy measurements. It allows for efficient energy management through
accurate measurements.