GE L30 User manual

GE
Grid Solutions
Instruction Manual
Product version: 7.4x
GE publication code: 1601-9050-AE3 (GEK-130983B)
L30
Line Current Differential System
1601-9050-AE3
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Copyright © 2017 GE Multilin Inc. All rights reserved.
L30 Line Current Differential System Instruction Manual for version 7.4x.
L30, FlexLogic, FlexElement, FlexCurve, FlexAnalog, FlexInteger, FlexState, EnerVista,
CyberSentry, HardFiber, Multilin, and GE Multilin are trademarks or registered trademarks
of GE Multilin Inc.
The contents of this manual are the property of GE Multilin Inc. This documentation is
furnished on license and may not be reproduced in whole or in part without the permission
of GE Multilin. The content of this manual is for informational use only and is subject to
change without notice.
Part number: 1601-9050-AE3 (April 2017)

L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL iii
L30 Line Current Differential System
Table of contents
1 INTRODUCTION 1.1 Safety symbols and definitions..................................................................... 1-1
1.1.1 General cautions and warnings .................................................................................... 1-1
1.2 For further assistance .................................................................................... 1-2
2PRODUCT
DESCRIPTION
2.1 Product description......................................................................................... 2-1
2.1.1 Overview................................................................................................................................... 2-1
2.1.2 Features.................................................................................................................................... 2-3
2.2 Pilot channel relaying ..................................................................................... 2-5
2.2.1 Inter-relay communications............................................................................................ 2-5
2.2.2 Channel monitor................................................................................................................... 2-7
2.2.3 Loopback test......................................................................................................................... 2-7
2.2.4 Direct transfer tripping ...................................................................................................... 2-8
2.3 Security.............................................................................................................. 2-8
2.4 Order codes ....................................................................................................2-11
2.4.1 Order codes with enhanced CT/VT modules.........................................................2-12
2.4.2 Order codes with process bus modules ..................................................................2-17
2.4.3 Replacement modules.....................................................................................................2-22
2.5 Signal processing...........................................................................................2-24
2.5.1 UR signal processing ........................................................................................................2-24
2.6 Specifications .................................................................................................2-26
2.6.1 Protection elements..........................................................................................................2-27
2.6.2 User-programmable elements ....................................................................................2-31
2.6.3 Monitoring..............................................................................................................................2-33
2.6.4 Metering..................................................................................................................................2-34
2.6.5 Inputs .......................................................................................................................................2-35
2.6.6 Power supply........................................................................................................................2-36
2.6.7 Outputs....................................................................................................................................2-36
2.6.8 Communication protocols..............................................................................................2-39
2.6.9 Inter-relay communications..........................................................................................2-40
2.6.10 CyberSentry security.........................................................................................................2-41
2.6.11 Environmental......................................................................................................................2-41
2.6.12 Type tests...............................................................................................................................2-42
2.6.13 Production tests..................................................................................................................2-42
2.6.14 Approvals ...............................................................................................................................2-43
2.6.15 Maintenance.........................................................................................................................2-43

iv L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
3 INSTALLATION 3.1 Unpack and inspect.........................................................................................3-1
3.2 Panel cutouts....................................................................................................3-2
3.2.1 Horizontal units......................................................................................................................3-2
3.2.2 Vertical units............................................................................................................................3-3
3.2.3 Rear terminal layout............................................................................................................3-8
3.3 Wiring ..............................................................................................................3-10
3.3.1 Typical wiring.......................................................................................................................3-10
3.3.2 Dielectric strength .............................................................................................................3-11
3.3.3 Control power......................................................................................................................3-11
3.3.4 CT/VT modules ....................................................................................................................3-12
3.3.5 Process bus modules ....................................................................................................... 3-14
3.3.6 Contact inputs and outputs ..........................................................................................3-14
3.3.7 Transducer inputs and outputs...................................................................................3-25
3.3.8 RS232 faceplate port........................................................................................................3-26
3.3.9 CPU communication ports ............................................................................................3-27
3.3.10 IRIG-B.......................................................................................................................................3-29
3.4 Pilot channel communications....................................................................3-30
3.4.1 Fiber: LED and ELED transmitters...............................................................................3-31
3.4.2 Fiber laser transmitters...................................................................................................3-31
3.4.3 G.703 interface....................................................................................................................3-32
3.4.4 RS422 interface...................................................................................................................3-36
3.4.5 Two-channel two-clock RS422 interface................................................................3-38
3.4.6 RS422 and fiber interface ..............................................................................................3-39
3.4.7 G.703 and fiber interface................................................................................................3-39
3.4.8 IEEE C37.94 interface .......................................................................................................3-40
3.4.9 C37.94SM interface...........................................................................................................3-43
3.5 Activate relay .................................................................................................3-46
3.6 Install software ..............................................................................................3-47
3.6.1 EnerVista communication overview ......................................................................... 3-47
3.6.2 System requirements.......................................................................................................3-48
3.6.3 Install software....................................................................................................................3-48
3.7 Add device to software.................................................................................3-49
3.7.1 Set IP address in UR..........................................................................................................3-50
3.7.2 Configure serial connection..........................................................................................3-55
3.7.3 Configure Ethernet connection...................................................................................3-56
3.7.4 Configure modem connection.....................................................................................3-58
3.7.5 Automatic discovery of UR devices...........................................................................3-58
3.8 Connect to the L30 ........................................................................................3-59
3.8.1 Connect to the L30 in EnerVista..................................................................................3-59
3.8.2 Use Quick Connect via the front panel RS232 port............................................3-60
3.8.3 Use Quick Connect via a rear Ethernet port..........................................................3-61
3.9 Set up CyberSentry and change default password.................................3-61
3.10 Import settings...............................................................................................3-62
4 INTERFACES 4.1 EnerVista software interface.........................................................................4-1
4.1.1 Introduction .............................................................................................................................4-1
4.1.2 Settings files ............................................................................................................................4-1
4.1.3 Event viewing..........................................................................................................................4-2
4.1.4 File support ..............................................................................................................................4-3
4.1.5 EnerVista main window .....................................................................................................4-3
4.1.6 Protection summary window..........................................................................................4-4
4.1.7 Settings templates................................................................................................................4-5
4.1.8 Secure and lock FlexLogic equations..........................................................................4-9
4.1.9 Settings file traceability...................................................................................................4-12

TABLE OF CONTENTS
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL v
4.2 Front panel interface ....................................................................................4-15
4.2.1 Front panel display............................................................................................................4-15
4.2.2 Front panel keypad............................................................................................................4-16
4.2.3 Menu navigation.................................................................................................................4-16
4.2.4 Menu hierarchy ...................................................................................................................4-16
4.2.5 Changing settings ..............................................................................................................4-17
4.2.6 Faceplate................................................................................................................................4-19
4.2.7 LED indicators ......................................................................................................................4-20
4.2.8 Custom LED labeling.........................................................................................................4-23
4.2.9 Breaker control....................................................................................................................4-28
4.2.10 Change passwords............................................................................................................4-29
4.2.11 Invalid password entry ....................................................................................................4-30
4.3 Logic diagrams...............................................................................................4-31
4.4 FlexLogic design and monitoring using Engineer....................................4-32
4.4.1 Design logic...........................................................................................................................4-34
4.4.2 Send file to and from device .........................................................................................4-44
4.4.3 Monitor logic.........................................................................................................................4-45
4.4.4 View front panel and print labels................................................................................4-46
4.4.5 Generate connectivity report........................................................................................4-47
4.4.6 Preferences ...........................................................................................................................4-47
4.4.7 Toolbars ..................................................................................................................................4-51
5 SETTINGS 5.1 Settings menu .................................................................................................. 5-1
5.2 Overview ........................................................................................................... 5-4
5.2.1 Introduction to elements .................................................................................................. 5-4
5.2.2 Introduction to AC sources .............................................................................................. 5-5
5.3 Product setup................................................................................................... 5-8
5.3.1 Security ..................................................................................................................................... 5-8
5.3.2 Display properties ..............................................................................................................5-26
5.3.3 Clear relay records.............................................................................................................5-28
5.3.4 Communications ................................................................................................................5-29
5.3.5 Modbus user map ..............................................................................................................5-93
5.3.6 Real-time clock....................................................................................................................5-94
5.3.7 Fault reports .........................................................................................................................5-98
5.3.8 Oscillography.....................................................................................................................5-100
5.3.9 Data logger ........................................................................................................................5-102
5.3.10 User-programmable LEDs ..........................................................................................5-104
5.3.11 User-programmable self-tests .................................................................................5-107
5.3.12 Control pushbuttons......................................................................................................5-107
5.3.13 User-programmable pushbuttons..........................................................................5-109
5.3.14 Flex state parameters...................................................................................................5-114
5.3.15 User-definable displays................................................................................................5-115
5.3.16 Installation..........................................................................................................................5-116
5.4 Remote resources........................................................................................5-117
5.4.1 Remote resources configuration .............................................................................5-117
5.5 System setup................................................................................................5-118
5.5.1 AC inputs .............................................................................................................................5-118
5.5.2 Power system....................................................................................................................5-119
5.5.3 Signal sources...................................................................................................................5-120
5.5.4 87L power system...........................................................................................................5-123
5.5.5 Breakers...............................................................................................................................5-130
5.5.6 Disconnect switches......................................................................................................5-135
5.5.7 FlexCurves...........................................................................................................................5-138
5.5.8 Phasor Measurement Unit ..........................................................................................5-145

vi L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
5.6 FlexLogic........................................................................................................5-165
5.6.1 FlexLogic operands........................................................................................................ 5-165
5.6.2 FlexLogic rules.................................................................................................................. 5-177
5.6.3 FlexLogic evaluation...................................................................................................... 5-177
5.6.4 FlexLogic example..........................................................................................................5-177
5.6.5 FlexLogic equation editor............................................................................................ 5-182
5.6.6 FlexLogic timers............................................................................................................... 5-182
5.6.7 FlexElements ..................................................................................................................... 5-182
5.6.8 Non-volatile latches.......................................................................................................5-187
5.7 Grouped elements .......................................................................................5-188
5.7.1 Overview ............................................................................................................................. 5-188
5.7.2 Setting group 1................................................................................................................. 5-188
5.7.3 Line differential elements............................................................................................ 5-189
5.7.4 Phase current ................................................................................................................... 5-194
5.7.5 Neutral current................................................................................................................. 5-206
5.7.6 Ground current ................................................................................................................ 5-214
5.7.7 Negative sequence current........................................................................................ 5-217
5.7.8 Breaker failure (ANSI 50BF)......................................................................................... 5-219
5.7.9 Voltage elements ............................................................................................................ 5-228
5.7.10 Supervising elements.................................................................................................... 5-235
5.8 Control elements .........................................................................................5-238
5.8.1 Overview ............................................................................................................................. 5-238
5.8.2 Trip bus ................................................................................................................................ 5-238
5.8.3 Setting groups .................................................................................................................. 5-240
5.8.4 Selector switch................................................................................................................. 5-241
5.8.5 Underfrequency (ANSI 81U)........................................................................................ 5-248
5.8.6 Frequency rate of change (ANSI 81R).................................................................... 5-249
5.8.7 Synchrocheck (ANSI 25) ............................................................................................... 5-251
5.8.8 Autoreclose (ANSI 79).................................................................................................... 5-257
5.8.9 Digital elements............................................................................................................... 5-263
5.8.10 Digital counters................................................................................................................ 5-266
5.8.11 Monitoring elements ..................................................................................................... 5-268
5.9 Inputs/outputs .............................................................................................5-282
5.9.1 Contact inputs.................................................................................................................. 5-282
5.9.2 Virtual inputs..................................................................................................................... 5-284
5.9.3 Contact outputs............................................................................................................... 5-285
5.9.4 Virtual outputs.................................................................................................................. 5-288
5.9.5 Resetting ............................................................................................................................. 5-288
5.9.6 Direct inputs and outputs ........................................................................................... 5-289
5.10 Transducer inputs/outputs........................................................................5-290
5.10.1 DCmA inputs...................................................................................................................... 5-290
5.10.2 RTD inputs .......................................................................................................................... 5-291
5.10.3 DCmA outputs .................................................................................................................. 5-292
5.11 Testing ...........................................................................................................5-296
5.11.1 Test mode function ........................................................................................................5-296
5.11.2 Test mode forcing........................................................................................................... 5-297
5.11.3 Phasor Measurement Unit test values.................................................................. 5-297
5.11.4 Force contact inputs ..................................................................................................... 5-298
5.11.5 Force contact outputs .................................................................................................. 5-299
5.11.6 Channel tests .................................................................................................................... 5-299
6 ACTUAL VALUES 6.1 Actual Values menu.........................................................................................6-1
6.2 Front panel........................................................................................................6-3
6.3 Status................................................................................................................. 6-4

TABLE OF CONTENTS
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL vii
6.3.1 Contact inputs ....................................................................................................................... 6-4
6.3.2 Virtual inputs........................................................................................................................... 6-4
6.3.3 RxGOOSE boolean inputs.................................................................................................. 6-4
6.3.4 RxGOOSE DPS inputs .......................................................................................................... 6-4
6.3.5 Contact outputs .................................................................................................................... 6-5
6.3.6 Virtual outputs ....................................................................................................................... 6-5
6.3.7 Autoreclose ............................................................................................................................. 6-5
6.3.8 RxGOOSE status.................................................................................................................... 6-5
6.3.9 RxGOOSE statistics .............................................................................................................. 6-6
6.3.10 Channel tests.......................................................................................................................... 6-6
6.3.11 Digital counters ..................................................................................................................... 6-7
6.3.12 Selector switches.................................................................................................................. 6-8
6.3.13 Flex States................................................................................................................................ 6-8
6.3.14 Ethernet .................................................................................................................................... 6-8
6.3.15 Real time clock synchronizing........................................................................................ 6-8
6.3.16 Direct inputs............................................................................................................................ 6-9
6.3.17 Incipient fault detector ...................................................................................................... 6-9
6.3.18 Remaining connection status.......................................................................................6-10
6.3.19 Parallel Redundancy Protocol (PRP)...........................................................................6-10
6.3.20 TxGOOSE status ..................................................................................................................6-11
6.4 Metering ..........................................................................................................6-11
6.4.1 Metering conventions.......................................................................................................6-11
6.4.2 Differential current ............................................................................................................6-15
6.4.3 Sources....................................................................................................................................6-16
6.4.4 Synchrocheck.......................................................................................................................6-20
6.4.5 Tracking frequency............................................................................................................6-21
6.4.6 Frequency rate of change..............................................................................................6-21
6.4.7 FlexElements.........................................................................................................................6-21
6.4.8 RxGOOSE analogs ..............................................................................................................6-22
6.4.9 Phasor Measurement Unit .............................................................................................6-22
6.4.10 PMU aggregator..................................................................................................................6-23
6.4.11 Transducer inputs and outputs ...................................................................................6-23
6.5 Records............................................................................................................6-24
6.5.1 Fault reports .........................................................................................................................6-24
6.5.2 Event records .......................................................................................................................6-25
6.5.3 Oscillography........................................................................................................................6-26
6.5.4 Data logger ...........................................................................................................................6-26
6.5.5 Phasor Measurement Unit records............................................................................6-27
6.5.6 Breaker maintenance.......................................................................................................6-27
6.6 Product information......................................................................................6-28
6.6.1 Model information..............................................................................................................6-28
6.6.2 Firmware revisions ............................................................................................................6-29
7 COMMANDS AND
TARGETS
7.1 Commands menu ............................................................................................ 7-1
7.1.1 Virtual inputs........................................................................................................................... 7-2
7.1.2 Clear records .......................................................................................................................... 7-2
7.1.3 Set date and time................................................................................................................. 7-3
7.1.4 Relay maintenance.............................................................................................................. 7-3
7.1.5 Phasor Measurement Unit one-shot........................................................................... 7-4
7.1.6 Security ..................................................................................................................................... 7-6
7.2 Targets menu ................................................................................................... 7-6
7.2.1 Target messages .................................................................................................................. 7-6
7.2.2 Relay self-tests ...................................................................................................................... 7-7

viii L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
8 APPLICATION OF
SETTINGS
8.1 CT requirements ..............................................................................................8-1
8.1.1 Introduction .............................................................................................................................8-1
8.1.2 CT saturation analysis tool...............................................................................................8-2
8.2 Current differential (87L) settings ................................................................8-3
8.2.1 Introduction .............................................................................................................................8-3
8.2.2 Current differential pickup................................................................................................8-4
8.2.3 Current differential restraint 1........................................................................................8-4
8.2.4 Current differential restraint 2........................................................................................8-4
8.2.5 Current differential break point......................................................................................8-4
8.2.6 CT tap..........................................................................................................................................8-4
8.3 Channel asymmetry compensation using GPS ..........................................8-6
8.3.1 Introduction .............................................................................................................................8-6
8.3.2 Compensation method 1...................................................................................................8-6
8.3.3 Compensation method 2...................................................................................................8-7
8.3.4 Compensation method 3...................................................................................................8-8
8.4 Instantaneous elements.................................................................................8-9
8.4.1 Instantaneous element error during L30 synchronization................................8-9
9 COMMISSIONING 9.1 Testing ...............................................................................................................9-1
9.1.1 Channel testing......................................................................................................................9-1
9.1.2 Clock synchronization tests .............................................................................................9-2
9.1.3 Current differential...............................................................................................................9-3
9.1.4 Local-remote relay tests....................................................................................................9-4
10 THEORY OF
OPERATION
10.1 Overview .........................................................................................................10-1
10.1.1 L30 design .............................................................................................................................10-1
10.1.2 L30 architecture .................................................................................................................10-2
10.1.3 Removal of decaying offset ..........................................................................................10-2
10.1.4 Phaselet computation ..................................................................................................... 10-2
10.1.5 Disturbance detection .....................................................................................................10-3
10.1.6 Fault detection ....................................................................................................................10-3
10.1.7 Ground differential element..........................................................................................10-5
10.1.8 Clock synchronization......................................................................................................10-6
10.1.9 Frequency tracking and phase locking ...................................................................10-6
10.1.10 Frequency detection.........................................................................................................10-7
10.1.11 Phase detection..................................................................................................................10-8
10.1.12 Phase-locking filter......................................................................................................... 10-10
10.1.13 Matching phaselets........................................................................................................ 10-11
10.1.14 Start-up................................................................................................................................ 10-12
10.1.15 Hardware and communication requirements.................................................. 10-12
10.1.16 Online estimate of measurement errors.............................................................. 10-12
10.1.17 CT saturation detection................................................................................................ 10-13
10.1.18 Charging current compensation ............................................................................. 10-14
10.1.19 Differential element characteristics....................................................................... 10-15
10.1.20 Relay synchronization................................................................................................... 10-16
10.2 Operating condition characteristics........................................................10-17
10.2.1 Description......................................................................................................................... 10-17
10.2.2 Trip decision example................................................................................................... 10-19
10.2.3 Trip decision test ............................................................................................................. 10-19
10.3 Fault locator .................................................................................................10-20
10.3.1 Description......................................................................................................................... 10-20

TABLE OF CONTENTS
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL ix
11 MAINTENANCE 11.1 Monitoring ......................................................................................................11-1
11.1.1 Devices with Site Targets................................................................................................11-1
11.1.2 Data with Modbus Analyzer ..........................................................................................11-1
11.2 General maintenance ...................................................................................11-3
11.2.1 In-service maintenance ..................................................................................................11-3
11.2.2 Out-of-service maintenance.........................................................................................11-3
11.2.3 Unscheduled maintenance (system interruption)...............................................11-3
11.3 Retrieve files...................................................................................................11-3
11.3.1 CyberSentry security event files ..................................................................................11-4
11.4 Copy settings to other device .....................................................................11-5
11.5 Compare settings ..........................................................................................11-5
11.5.1 Compare against defaults .............................................................................................11-5
11.5.2 Compare two devices.......................................................................................................11-6
11.6 Back up and restore settings ......................................................................11-6
11.6.1 Back up settings..................................................................................................................11-7
11.6.2 Restore settings ..................................................................................................................11-9
11.7 Upgrade software........................................................................................11-11
11.8 Upgrade firmware .......................................................................................11-12
11.9 Replace module ...........................................................................................11-13
11.10 Battery...........................................................................................................11-14
11.10.1 Replace battery for SH/SL power supply .............................................................11-14
11.10.2 Dispose of battery...........................................................................................................11-15
11.11 Clear files and data after uninstall ..........................................................11-19
11.12 Repairs...........................................................................................................11-19
11.13 Storage ..........................................................................................................11-20
11.14 Disposal.........................................................................................................11-20
AFLEXANALOG
OPERANDS
A.1 FlexAnalog items .............................................................................................A-1
B RADIUS SERVER
CONFIGURATION
B.1 RADIUS server configuration .........................................................................B-1
C COMMAND LINE
INTERFACE
C.1 Command line interface .................................................................................C-1
D MISCELLANEOUS D.1 Warranty ...........................................................................................................D-1
D.2 Revision history ...............................................................................................D-1
ABBREVIATIONS
INDEX

x L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS

L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 1-1
L30 Line Current Differential System
Chapter 1: Introduction
Introduction
This chapter outlines safety and technical support information.
1.1 Safety symbols and definitions
Before attempting to install or use the device, review all safety indicators in this document to help prevent injury,
equipment damage, or downtime.
The following safety and equipment symbols are used in this document.
1.1.1 General cautions and warnings
The following general safety precautions and warnings apply.
Follow the requirements of this manual, including adequate wiring size and type, terminal torque settings, voltage,
current magnitudes applied, and adequate isolation/clearance in external wiring from high to low voltage circuits.
Use the device only for its intended purpose and application.
Ensure that all ground paths are uncompromised for safety purposes during device operation and service.
Ensure that the control power applied to the device, the AC current, and voltage input match the ratings specified on
the relay nameplate. Do not apply current or voltage in excess of the specified limits.
Indicates a hazardous situation which, if not avoided, will result in death or serious injury.
Indicates a hazardous situation which, if not avoided, could result in death or serious injury.
Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.
Indicates practices not related to personal injury.
Ensure that all connections to the product are correct so as to avoid accidental risk of shock
and/or fire, for example such as can arise from high voltage connected to low voltage terminals.

1-2 L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
FOR FURTHER ASSISTANCE CHAPTER 1: INTRODUCTION
1
Only qualified personnel are to operate the device. Such personnel must be thoroughly familiar with all safety
cautions and warnings in this manual and with applicable country, regional, utility, and plant safety regulations.
Hazardous voltages can exist in the power supply and at the device connection to current transformers, voltage
transformers, control, and test circuit terminals. Make sure all sources of such voltages are isolated prior to
attempting work on the device.
Hazardous voltages can exist when opening the secondary circuits of live current transformers. Make sure that
current transformer secondary circuits are shorted out before making or removing any connection to the current
transformer (CT) input terminals of the device.
For tests with secondary test equipment, ensure that no other sources of voltages or currents are connected to such
equipment and that trip and close commands to the circuit breakers or other switching apparatus are isolated,
unless this is required by the test procedure and is specified by appropriate utility/plant procedure.
When the device is used to control primary equipment, such as circuit breakers, isolators, and other switching
apparatus, all control circuits from the device to the primary equipment must be isolated while personnel are working
on or around this primary equipment to prevent any inadvertent command from this device.
Use an external disconnect to isolate the mains voltage supply.
Personal safety can be affected if the product is physically modified by the end user. Modifications to the product
outside of recommended wiring configuration, hardware, or programming boundaries is not recommended end-use
practice. Product disassembly and repairs are not permitted. All service needs to be conducted by the factory.
1.2 For further assistance
For product support, contact the information and call center as follows:
GE Grid Solutions
650 Markland Street
Markham, Ontario
Canada L6C 0M1
Worldwide telephone: [phone]
Europe/Middle East/Africa telephone: [phone]
North America toll-free: 1 800 547 8629
Fax: [phone]
Worldwide e-mail: multilin.t[email protected]
Europe e-mail: multilin.tech.[email protected]
Website: http://www.gegridsolutions.com/multilin
When contacting GE by e-mail, optionally include a device information file, which is generated in the EnerVista software by
clicking the Service Report button.
LED transmitters are classified as IEC 60825-1 Accessible Emission Limit (AEL) Class 1M. Class 1M
devices are considered safe to the unaided eye. Do not view directly with optical instruments.
This product is rated to Class A emissions levels and is to be used in Utility, Substation Industrial
environments. Not to be used near electronic devices rated for Class B levels.

CHAPTER 1: INTRODUCTION FOR FURTHER ASSISTANCE
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 1-3
1
Figure 1-1: Generate service report

1-4 L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
FOR FURTHER ASSISTANCE CHAPTER 1: INTRODUCTION
1

L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 2-1
L30 Line Current Differential System
Chapter 2: Product description
Product descript ion
This chapter outlines the product, order codes, and specifications.
2.1 Product description
2.1.1 Overview
The L30 Line Current Differential System is part of the Universal Relay (UR) series of products. It is a digital current
differential relay system with an integral communications channel interface.
The L30 is intended to provide complete protection for transmission lines of any voltage level. Both three phase and single
phase tripping schemes are available. Models of the L30 are available for application on both two and three terminal lines.
The L30 uses per phase differential at 64 kbps transmitting two phaselets per cycle. The current differential scheme is
based on innovative patented techniques developed by GE. The L30 algorithms are based on the Fourier transform–
phaselet approach and an adaptive statistical restraint. The restraint is similar to a traditional percentage differential
scheme, but is adaptive based on relay measurements. When used with a 64 kbps channel, the innovative phaselets
approach yields an operating time of 1.0 to 1.5 cycles (typical). The adaptive statistical restraint approach provides both
more sensitive and more accurate fault sensing. This allows the L30 to detect relatively higher impedance single line to
ground faults that existing systems may not. The basic current differential element operates on current input only. Long
lines with significant capacitance can benefit from charging current compensation if terminal voltage measurements are
applied to the relay. The voltage input is also used for some protection and monitoring features, such as directional
elements, fault locator, metering, and distance backup.
The L30 is designed to operate over different communications links with various degrees of noise encountered in power
systems and communications environments. Since correct operation of the relay is completely dependent on data
received from the remote end, special attention must be paid to information validation. The L30 incorporates a high
degree of security by using a 32-bit CRC (cyclic redundancy code) inter-relay communications packet.
Several options are available for communication. A faceplate RS232 port can be used to connect to a computer for the
programming of settings and the monitoring of actual values. The rear RS485 port allows independent access by operating
and engineering staff. It can be connected to system computers with baud rates up to 115.2 kbps. All serial ports use the
Modbus RTU protocol. The IEC 60870-5-103 protocol is supported on the RS485 interface. IEC 60870-5-103, DNP, and
Modbus cannot be enabled simultaneously on this interface. Also only one of the DNP, IEC 60870-5-103, and IEC 60870-5-
104 protocols can be enabled at any time on the relay. When the IEC 60870-5-103 protocol is chosen, the RS485 port has a
fixed even parity and the baud rate can be either 9.6 kbps or 19.2 kbps. The 100Base-FX or 100Base-T Ethernet interface
provides fast, reliable communications in noisy environments. The Ethernet port supports IEC 61850, IEC 61850-90-5,
Modbus/TCP, TFTP, and PTP (according to IEEE Std. 1588-2008 or IEC 61588), and it allows access to the relay via any

2-2 L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
PRODUCT DESCRIPTION CHAPTER 2: PRODUCT DESCRIPTION
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standard web browser (L30 web pages). The IEC 60870-5-104 protocol is supported on the Ethernet port. The Ethernet port
also supports the Parallel Redundancy Protocol (PRP) of IEC 62439-3 (clause 4, 2012) when purchased as an option.
Secure Routable GOOSE (R-GOOSE) is supported with software options.
In addition to current differential protection, the relay provides multiple backup protection for phase and ground faults. For
overcurrent protection, the time overcurrent curves can be selected from a selection of standard curve shapes or a
custom FlexCurve™ for optimum co-ordination.
The L30 incorporates charging current compensation for applications on very long transmission lines without loss of
sensitivity. The line capacitive current is removed from the terminal phasors.
For breaker-and-a-half or ring applications, the L30 design provides secure operation during external faults with possible
CT saturation.
Voltage, current, and power metering is built into the relay as a standard feature. Current parameters are available as total
waveform RMS magnitude, or as fundamental frequency only RMS magnitude and angle (phasor).
The L30 uses flash memory technology that allows field upgrading as new features are added. Firmware and software are
upgradable.
The following single-line diagram illustrates the relay functionality using American National Standards Institute (ANSI)
device numbers.
Table 2-1: ANSI device numbers and functions supported
Device number Function Device number Function
25 Synchrocheck 51_2 Negative-sequence time overcurrent
27P Phase undervoltage 52 AC circuit breaker
27X Auxiliary undervoltage 59N Neutral overvoltage
49 Thermal overload protection 59P Phase overvoltage
50BF Breaker failure 59_2 Negative-sequence overvoltage
50DD Current disturbance detector 59X Auxiliary overvoltage
50G Ground instantaneous overcurrent 67N Neutral directional overcurrent
50N Neutral instantaneous overcurrent 67P Phase directional overcurrent
50P Phase instantaneous overcurrent 79 Automatic recloser
50_2 Negative-sequence instantaneous overcurrent 81R Rate of change frequency
51G Ground time overcurrent 81U Underfrequency
51N Neutral time overcurrent 87L Segregated line current differential
51P Phase time overcurrent 87LG Line ground current differential

CHAPTER 2: PRODUCT DESCRIPTION PRODUCT DESCRIPTION
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 2-3
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Figure 2-1: Single-line diagram
Table 2-2: Other device functions
2.1.2 Features
2.1.2.1 Line current differential
• Phase segregated, high-speed digital current differential system
• Overhead and underground AC transmission lines, series compensated lines
• Two-terminal and three-terminal line applications
Function Function Function
Breaker arcing current (I2t) Event recorder Oscillography
Breaker control Fault locator and fault reporting Setting groups (6)
Channel tests FlexElements™ (8) Stub bus
Contact inputs (up to 96) FlexLogic equations Synchrophasor (PMU)
Contact outputs (up to 64) IEC 60870-5-103 communications Time synchronization over IRIG-B or IEEE
1588
Control pushbuttons IEC 61850 communications Time synchronization over SNTP
CT failure detector IEC 62351-9 data and communications
security Transducer inputs and outputs
CyberSentry™ security Incipient cable fault detection User-definable displays
Data logger Metering: Current, voltage, power,
frequency, power factor, 87L current, local
and remote phasors, harmonics, THD
User-programmable LEDs
Digital counters (8) Modbus communications User-programmable pushbuttons
Digital elements (48) Modbus user map User-programmable self-tests
Direct inputs (8 per pilot channel) Non-volatile latches Virtual inputs (64)
Disconnect switches Non-volatile selector switch Virtual outputs (96)
DNP 3.0 or IEC 60870-5-104 protocol Open pole detector VT fuse failure

2-4 L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
PRODUCT DESCRIPTION CHAPTER 2: PRODUCT DESCRIPTION
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• Zero-sequence removal for application on lines with tapped transformers connected in a grounded wye on the line
side
• GE phaselets approach based on the Discrete Fourier Transform with 64 samples per cycle and transmitting two time-
stamped phaselets per cycle
• Adaptive restraint approach improving sensitivity and accuracy of fault sensing
• Accommodates in-zone transformer with a magnitude and phase compensation and second harmonic inhibit during
transformer magnetizing inrush
• Continuous clock synchronization via the distributed synchronization technique
• Increased transient stability through DC decaying offset removal
• Accommodates up to five times CT ratio differences
• Peer-to-peer (master-master) architecture changing to master-slave via DTT (if channel fails) at 64 kbps
• Charging current compensation
• Interfaces direct fiber, multiplexed RS422, IEEE C37.94, and G.703 connections with relay ID check
• Per-phase line differential protection direct transfer trip plus eight user-assigned pilot signals via the communications
channel
• Secure 32-bit CRC protection against communications errors
• Channel asymmetry (up to 10 ms) compensation using GPS satellite-controlled clock
2.1.2.2 Backup protection
• DTT provision for pilot schemes
• Two-element time overcurrent and two-element instantaneous overcurrent directional phase overcurrent protection
• Two-element time overcurrent and two-element instantaneous overcurrent directional zero-sequence protection
• Two-element time overcurrent and two-element instantaneous overcurrent negative-sequence overcurrent
protection
• Undervoltage and overvoltage protection
2.1.2.3 Additional protection
• Breaker failure protection
• Stub bus protection
• VT and CT supervision
• GE Multilin sources approach allowing grouping of different CTs and VTs from multiple input channels
• Open pole detection
• Breaker trip coil supervision and seal-in of trip command
• FlexLogic allowing creation of user-defined distributed protection and control logic
2.1.2.4 Control
• One and two breaker configuration for breaker-and-a-half and ring bus schemes, pushbutton control from the relay
• Auto-reclosing and synchrochecking
• Breaker arcing current
2.1.2.5 Monitoring
• Oscillography of current, voltage, FlexLogic operands, and digital signals (1 ×128 cycles to 31 ×8 cycles configurable)
• Events recorder: 1024 events
• Fault locator

CHAPTER 2: PRODUCT DESCRIPTION PILOT CHANNEL RELAYING
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 2-5
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2.1.2.6 Metering
• Actual 87L remote phasors, differential current, channel delay, and channel asymmetry at all line terminals of line
current differential protection
• Line current, voltage, real power, reactive power, apparent power, power factor, and frequency
2.1.2.7 Communications
• Front panel RS232 port: 19.2 kbps
• Rear RS485 port: up to 115 kbps
• Rear 100Base-FX Ethernet port supporting the IEC 61850 protocol
2.2 Pilot channel relaying
2.2.1 Inter-relay communications
Dedicated inter-relay communications can operate over 64 kbps digital channels or dedicated fiber optic channels.
Available interfaces include:
• RS422 at 64 kbps
• G.703 at 64 kbps
• Dedicated fiber optics at 64 kbps, including
– 820 nm multimode fiber with an LED transmitter
– 1300 nm multimode fiber with an LED transmitter
– 1300 nm single-mode fiber with an ELED transmitter
– 1300 nm single-mode fiber with a laser transmitter
– 1550 nm single-mode fiber with a laser transmitter
– IEEE C37.94 820 nm multimode fiber with an LED transmitter
All fiber optic options use an ST connector. L30 models are available for use on two or three terminal lines. A two terminal
line application requires one bidirectional channel. However, in two terminal line applications, it is also possible to use an
L30 relay with two bidirectional channels. The second bidirectional channel provides a redundant backup channel with
automatic switchover if the first channel fails.
The L30 current differential relay is designed to function in a peer-to-peer or master-to-master architecture. In the peer-to-
peer architecture, all relays in the system are identical and perform identical functions in the current differential scheme. In
order for every relay on the line to be a peer, each relay must be able to communicate with all of the other relays. If there is
a failure in communications among the relays, the relays revert to a master-to-peer architecture on a three-terminal
system, with the master as the relay that has current phasors from all terminals. Using two different operational modes
increases the dependability of the current differential scheme on a three-terminal system by reducing reliance on
communications.
The main difference between a master and a slave L30 is that only a master relay performs the actual current differential
calculation, and only a master relay communicates with the relays at all other terminals of the protected line.
At least one master L30 relay must have live communications to all other terminals in the current differential scheme; the
other L30 relays on that line operate as slave relays. All master relays in the scheme are equal, and each performs all
functions. Each L30 in the scheme determines if it is a master by comparing the number of terminals on the line to the
number of active communication channels.
The slave terminals only communicate with the master; there is no slave-to-slave communications path. As a result, a
slave L30 cannot calculate the differential current. When a master L30 relay issues a local trip signal, it also sends a direct
transfer trip (DTT) signal to all of the other L30 relays on the protected line.
If a slave L30 issues a trip from one of its backup functions, it can send a transfer trip signal to its master and other slave
relays if such option is designated. Because a slave cannot communicate with all the relays in the differential scheme, the
master then “broadcasts” the direct transfer trip (DTT) signal to all other terminals.

2-6 L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
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The slave L30 performs the following functions:
• Samples currents and voltages
• Removes DC offset from the current via the mimic algorithm
• Creates phaselets
• Calculates sum of squares data
• Transmits current data to all master L30 relays
• Performs all local relaying functions
• Receives current differential DTT and Direct Input signals from all other L30 relays
• Transmits direct output signals to all communicating relays
• Sends synchronization information of local clock to all other L30 clocks
The master L30 relay performs the following functions:
• Performs all functions of a slave L30
• Receives current phasor information from all relays
• Performs the current differential algorithm
• Sends a current differential DTT signal to all L30 relays on the protected line
In the peer-to-peer mode, all L30 relays act as masters.