Warnings, Cautions, and Notes as used in this publication
Warnings
WARNING!Warning notices are used in this publication to emphasize that hazardous voltages,
currents, or other conditions that could cause personal injury exist in this equipment or may be
associated with its use.
Warning notices are also used for situations in which inattention or lack of equipment knowledge
could cause either personal injury or damage to equipment.
Cautions
CAUTION:Caution notices are used for situations in which equipment might be damaged if care is
not taken.
Notes
NOTE:Notes call attention to information that is especially significant to understanding and
operating the equipment.
This document is based on information available at the time of its publication. While efforts have been
made to ensure accuracy, the information contained herein does not cover all details or variations in
hardware and software, nor does it provide for every possible contingency in connection with
installation, operation, and maintenance. Features may be described in here that are not present in all
hardware and software systems. GE Consumer & Industrial assumes no obligation of notice to holders
of this document with respect to changes subsequently made.
GE Consumer & Industrial makes no representation or warranty, expressed, implied, or statutory, with
respect to, and assumes no responsibility for the accuracy, completeness, sufficiency, or usefulness of
the information contained herein. No warrantees of merchantability or fitness for purpose shall apply.
Entellisys™, EntelliGuard™, and FlexLogic™ are trademarks of the General Electric Company.
Modbus RTU is a registered trademark of AEG Schneider Automation.
Please have your Entellisys System Summary # and Sub # ready when calling. This information can be
found on the Entellisys HMI on the System Health screen by clicking the Job Info button.
Post Sales Service
GE Switchgear
510 Agency Road
West Burlington, IA 52655
The Entellisys™ Low-Voltage Switchgear architecture is unique. The central processor unit (CPU)
is the basis of this new protection-and-control architecture. The CPU provides protection and
control functions over the entire low-voltage switchgear system.
The key advantage of this architecture is that the CPU has all the information from all circuit
breakers simultaneously. The architecture also has built in redundancy to increase system
availability.
Current transformers (CTs) and potential transformers (PTs) measure current and voltage and
transmit the analog information to the EntelliGuard™. The Messenger digitizes and sends the
information over the Messenger communication network to two redundant CPUs.
The CPUs make protection decisions, capture events, process waveform data, and provide
status information. For example, if the CPUs identify a trip condition at a circuit breaker, the CPU
alerts the EntelliGuard Messenger at that circuit breaker, which then actuates the circuit breaker
and returns the circuit breaker status to the CPU.
Modbus
external components such as the Entellisys HMI, SCADA, or other Building Automation Systems.
The Human Machine Interface (HMI) is the central user interface for the system. HMIs are
touchscreen computers located in-gear or near-gear (see Touchscreen HMI on page 22
Remote HMIs are available for desktop users who want to view the switchgear from their office.
®
communication, an open industry standard protocol, is provided as an interface to
) and
Description of operation11
Digital I/O is provided for customer-specific inputs and outputs. This equipment is resident in the
1
switchgear and is connected through the CPUs. Digital I/O and custom control schemes will run
in the CPUs if enabled.
In summary, Entellisys changes the protection paradigm from individual circuit protection to
system protection.
CAUTION:Users that have been assigned Group Permissions by the System Administrator for
features that allow the changing of settings and/or access to control functions must be
established as qualified personnel only. See Chapter 4 in DEH-230, Entellisys Low Voltage
Switchgear System Administrator Manual, for more information about programming user
permissions. As a reminder, users with such privileges will be presented with the following
screen upon initial login:
Figure 1-2 Initial login Caution screen
1.2 Switchgear installations
There are two primary installation methods in the switchgear:
• Standard
• Split-redundant
With standard installation, redundant components such as the CPUs, Messenger switches, and
UPSs are installed together in the equipment. This method optimizes footprint and convenience
of maintenance.
With split-redundant installation, redundant components such as the CPUs, Messenger
switches, and UPSs are split-up with at least one switchgear stack separating them. This
method optimizes system availability.
For more information, see DEH-237 Entellisys Low Voltage Switchgear Installation and
Maintenance Instruction Guide.
System architecture12
1.3 System components
Following are brief descriptions of each component in the Entellisys system.
1.3.1 EntelliGuard circuit breaker
EntelliGuard low-voltage power circuit breakers control and protect power circuits up to
600 volts. They will safely switch loads and automatically clear circuits when abnormal
conditions occur. These include short circuits, sustained overloads, ground faults, and other
programmable conditions.
The EntelliGuard circuit breakers are available in 800 ampere, 1,600 ampere, 2,000 ampere,
3,200 ampere, 4,000 ampere, and 5,000 ampere frame sizes. These values represent the
maximum continuous-current rating of each frame.
Circuit breakers may be equipped with a combination of accessories and interlocking devices.
Figure 1-3 EntelliGuard small frame circuit breaker
1
•The network interlock accessory selectively prevents the closing of specific circuit
breakers in the electrical distribution network. The CPU sets and resets network interlock
devices remotely while continuously monitoring their status. For example, in a
double-ended substation, these devices could be used to interlock the main and tie
circuit breakers to prevent connecting two unsynchronized power sources.
•The bell alarm lockout accessory prevents a circuit breaker from closing after receiving
a trip command from the EntelliGuard Messenger. Closing of the circuit breaker is
permitted only after the lockout is reset manually at the front of the circuit breaker.
For more information, see the following EntelliGuard Circuit Breaker Instruction Books:
Current transformers (CTs) are sensors that measures current. Each circuit breaker requires
input from three CTs (one per phase) and an optional neutral CT. Unlike traditional switchgear,
this single set of CTs provides the necessary current sensing for all needs including protection,
metering, and control.
The CTs are attached to the power bus behind the circuit breaker in the circuit breaker
compartment. Only Entellisys CTs may be used with the Entellisys system.
CTs either come in a 3-pack (shown in Figure 1-4) or as single CTs.
Figure 1-4 CT 3-pack
System architecture14
1.3.3 Potential transformers
Potential or voltage transformers (PTs) are sensors that measure voltage. Unlike traditional
switchgear, only the main (or source) circuit breakers in the system require PTs. This hardware
and wiring reduction is possible because of the central processor architecture and the sampling
synchronization maintained by the system.
Three PTs, one for each phase, are required on the main circuit breakers in the system. The
remaining circuit breakers reference one circuit breaker with physical PTs and use that source's
voltage readings for metering calculations. This source reference may change as the system
topology changes.
The PTs are located outside the circuit breaker compartments in auxiliary compartments.
Figure 1-5 Entellisys PT
1
System components15
1
1.3.4 EntelliGuard Messenger
The EntelliGuard Messenger electronic device provides the interface between the circuit
breakers and the CPUs in the Entellisys system.
Following is a summary of the Messenger’s functionality:
• Digitizes all switchgear signals
• Communicates the raw samples to CPUs via the Messenger network
• Controls the circuit breaker
• Performs independent backup trip capability at all times
• Powered by dual 120v control power sources or self-powered from the current sensors
• Provides LED illumination of circuit breaker status, power status, communication status, and
GE “Locator” information
• Provides seal-able switches to set CT rating, and (long time) multiplier setting
• Provides a test connector for trip curve testing using the Entellisys System Test Kit
1.3.4.1 Messenger User Interface
The Messenger User Interface, as show in Figure 1-6, is described below.
Figure 1-6 Messenger front
LED Indicator Lights
• Locate: LED blinks for 10 or 30 seconds on command from the HMI to help operator
physically locate a circuit breaker in the switchgear lineup.
• Com1, Com2: Illuminates when Ethernet communication is plugged in and ready to
communicate.
• Power: Illuminates when either Control Power A or Control Power B sources are powering the
node.
• Circuit Breaker Status Open: Illuminates when the circuit breaker is Open. This sensor is
independent of the circuit breaker Close sensor.
• Circuit Breaker Status Closed: Illuminates when the circuit breaker is Closed. This sensor is
independent of the circuit breaker Open sensor.
Switches
• Rating: Ampere rating of the circuit in use. Maximum value is the CT Rating.
• Setting: Multiplier setting for Long Time Overcurrent Protection, specified as X times the
Rating switch value.
Rating Label
• Frame: Circuit breaker frame size, in Amperes, represents the maximum continuous-current
rating.
• CT: Maximum Ampere rating of the CTs.
System architecture16
Test Connector
Connection point between the Entellisys System Test Kit and the Messenger.
Figure 1-7 EntelliGuard Messenger
The Messenger is located directly above the circuit breaker compartment.
1.3.5 Compartment ID button
The Compartment ID button stores compartment configuration information in non-volatile
memory. It informs the system about the circuit breaker residing in the cubicle.
The Compartment ID button is shipped inserted into the EntelliGuard Messenger, tethered to the
equipment, and does not require any user interface during normal operation. It remains within
the switchgear cubicle at all times.
1
WARNING!Compartment ID buttons are set at the factory and are not interchangeable
between compartments. Failure to utilize the correct compartment ID button can result in
personal injury and damage to equipment.
The ID button provides the system with necessary information such as circuit breaker frame
size, CT size, and overcurrent protection capabilities as follows:
• Ground fault protection always on
• Ground fault protection always off
• Ground fault protection switchable (enabled/disabled) in the HMI
If the ground fault protection options need to change, a replacement ID button must be ordered
(GE CAT# ETSCOMPID).
System components17
Figure 1-8 Compartment ID Button un-tethered from switchgear
1
1.3.6 Messenger communications network
The Messenger communications networks are closed, dedicated LANs for transmitting
information between the Messengers and the CPUs in the system. The LANs are for the
Entellisys system only and should never be connected to other networks.
CAUTION:Failure to maintain a dedicated LAN will result in the EntelliGuard Messenger
reverting to back-up Overcurrent protection.
A Messenger switch is required to route information appropriately. The communication wiring
required is 100BaseT, CAT5 cables.
Each CPU resides on a separate network, providing redundant communications.
1.3.7 Messenger switch
The Messenger switch enables the communication network between the Messengers and
corresponding CPU. A Messenger switch is required for each of the two redundant networks. The
number of ports provided is determined by the number of circuit breakers in the system. Each
circuit breaker requires its own port in the switch.
The largest switch provides only 24 ports. If the number of circuit breakers in the system
exceeds 22, a pyramid switch scheme, utilizing multiple switches, is required.
System architecture18
1.3.8 CPU
1
The CPU is a rack-mount industrial computer running a real-time operating system. The CPU
provides the processing capability to support all switchgear functions. Two redundant CPUs
(CPU A and CPU B) are used per lineup, supporting up to 30 circuit breakers.
The CPUs run simultaneously. If one CPU has an issue, the other continues to run providing
redundancy. One CPU should be running at all times to maintain the highest level of protection.
In the event that the Messenger-to-CPU communication network is down or power to the CPU is
not available, the EntelliGuard Messenger will provide back-up overcurrent protection
functionality.
The redundant CPUs are synchronized by a common connection to a synch clock. Each CPU has
a slot for synch clock, although only one synch clock is used per system. The synch clock is
programmed for either 60 Hertz or 50 Hertz frequency operation.
Each CPU has two slots for optional digital I/O cards.
Figure 1-9 Redundant CPUs with synch clock connection
1.3.9 Synch clock
To maintain system synchronization, a mechanism exists to provide a single sampling time
source. This time source is provided on a separate hardware card, called the Synch Clock. The
Synch Clock sits in CPU A and has a connection to CPU B.
In the event of an issue with the Synch Clock or its connections, the CPUs fall-back to software
synch functionality. When this occurs CPU A maintains full functionality. As time drifts, CPU B
may suspend advanced multi-source protection and may not be able to provide metering
information for the circuit breakers without PTs. If CPU A is powered down to provide
maintenance, CPU B will run full functionality.
System components19
1
1.3.10 Digital I/O
The Digital I/O equipment provides programmable input and output logic for customer-specific
requirements.
Examples include the following:
• Sound a horn when a circuit breaker is open
• Trigger an output when voltage exceeds a value
The redundant digital I/O option provides signal processing to/from either CPU. One CPU (the
Master) processes the information and responds. The other provides a backup of the Master
fails. Redundant digital I/O is recommended if any of the signals are critical to the operation of
the system. Critical I/O examples include the following:
• Inputs to automatic throw-over schemes
• Inputs that must trip circuit breaker (such as high transformer pressure)
For more information on Digital I/O, see Digital I/O on page 127
1.3.10.1 CPU digital I/O cards
The input and output signals from the CPU are transferred through the CPU digital I/O Cards.
Each card supports 64 bi-directional points that range from 0 to 5 volts. A maximum of two
cards may be inserted for a total of 128 I/O points. The cards come installed in the CPU upon
purchase.
1.3.10.2 Digital I/O cable
This cable connects the CPU digital I/O card to the terminal block. Each cable transmits 64 I/O
points.
1.3.10.3 Terminal block
The terminal block accepts 64 I/O signals from the CPU digital I/O card through a single cable
and breaks out the individual signals into 64 terminals for wiring.
1.3.10.4 “OR” boards
These boards are only required for redundant digital I/O. The output signals from both CPUs
must be “Horde” together, between the terminal blocks and the relay blocks, to prevent
increased voltages from damaging the relays. Each “OR” board supports 16 output signals.
.
1.3.10.5 Relay blocks
The relay blocks hold solid state input and output relays (16 per block).
Relay blocks are configured as all inputs or all outputs. Unused digital I/O points may have
relays left off.
1.3.10.6 Relays
The input relays transform the customer input (120 Vac or 24-125 Vdc) to 5V inputs for the
Entellisys system.
The output relays are either opened or closed based on programmable logic in the Entellisys
system.
System architecture20
1.3.10.7 Digital I/O customer interface wiring
The customer interface to the digital I/O is provided at the I/O module relay blocks. These relay
blocks and the customer wire termination points are mounted in the digital I/O cubicle and are
accessed from the front of the switchgear. Control conduits are terminated in the rear cable
compartment and the digital I/O wiring is routed to the front of the switchgear through an
opening in the digital I/O cubicle rear barrier.
1.3.11 System interface Ethernet communication network
The system interface Ethernet communication network is a 10/100 Mbps Ethernet LAN that
provides an interface into the Entellisys system for systems such as the Entellisys HMI, SCADA
systems, building automation, HVAC systems or other. The system interface Ethernet
communication network provides information and control of all circuit breakers in the system.
The external communications network will use 100BaseT (copper twisted pair) CAT5 or better
cabling. A fiber optic connection is available as an option.
1.3.12 System interface Ethernet switch
The interface between the Entellisys system and the external world is through the system
interface Ethernet switch, an industrial hardened 10/100 Mbps Ethernet switch. An 8-port
copper model is standard. Optionally customers may choose a 9-port model with an additional
fiber port for external gear communication. The fiber port supports 100FL connections only.
1
Figure 1-10 Ethernet switch, 8-port
System components21
1
1.3.13 Touchscreen HMI
The system interface for the Entellisys switchgear will be through one or more touchscreen
computer displays. The display is driven by a separate computer and communicates to the
CPUs through an Ethernet connection. The System Interface Ethernet Switch provides the
physical interface.
The HMI communicates primarily with one of the CPUs but can switch to the other in event of a
failure. Functionality provided by the HMI includes:
• Programmable user login to grant/deny access to specific features
• Animated one-line that shows the current status of the entire system
• Circuit breaker status, circuit breaker control
• Metering, demand logging, harmonics
• User settings for overcurrent protection, relay protection, advanced multi-source protection.
This may be writable or read-only depending on permissions granted.
• Customer-specific discrete I/O programming and status
• Customer-specific control scheme programming and status
• Sequence of events
• System health – showing the health of the Entellisys equipment
NOTE:The HMI is not critical to the protection functionality of the system. The HMI can be
brought down for service with no loss of protection in the system.
1.3.13.1 In-gear HMI
Typically a touchscreen HMI is installed in the switchgear. This is deemed an “in-gear” HMI.
A redundant in-gear HMI is available as an option. The redundant HMI is also a touchscreen HMI
located in the gear.
1.3.13.2 Near-gear HMI
Optionally, a touchscreen HMI may be installed near the switchgear equipment, but away from
the hazardous arc flash zone. This can be in a separate stack or in a wall-mount box up to
250 feet from the switchgear. This is deemed a “near-gear” HMI.
System architecture22
1.3.14 Remote HMI
The Entellisys system offers desktop access to the switchgear with the same HMI software
installed in the gear. The remote HMI software can be installed on any Windows 2000 desktop
computer and requires an intranet connection to the switchgear. The intranet connection is
connected to the system interface Ethernet switch.
Two versions of remote HMI are offered:
• User Interactive
Permissions are programmable and can be set for full Administrator access down to Guest
access.
• Viewer
Allows read-only access to the system.
1.3.15 VPN firewall device
Virtual Private Network (VPN) firewall device provides business-class network security providing
Denial of Service (DoS) protection and intrusion detection using Stateful Packet Inspection (SPI),
URL access and content filtering, logging, reporting, and real-time alerts. Up to eight users can
access the system simultaneously.
1
It is strongly recommended that anytime an Entellisys system is connected to the intranet, a
VPN firewall be installed to protect the Entellisys system from network threats.
For more information, see DEH-230 Entellisys Low Voltage Switchgear System Administrator
Manual.
1.3.16 Control power
Control Power is 120 Vac, 50 and 60 Hz only. Uninterruptible power is provided standard with
each system. The control power scheme is specific to each installation and constructed from
standard elements using defined practices for Entellisys control power distribution.
1.3.17 UPS
Two Universal Power Supplies are installed in the switchgear to provide backup power to the
control power network. The UPSs are powered from the primary power buses (utility or
generator) and are redundant.
The UPS serves all 120 Vac control power network devices. It does not power the charging
motors of electrically operated circuit breakers.
For more information on the Control Power Network, see Control power and UPS configuration
on page 183.
For more information on the UPS, see the “GE Digital Energy GT Series™ - UL, Product
Description” at www.gedigitalenergy.com
.
System components23
1
1.3.18 UPS to HMI connection
The Entellisys system provides event/alarm/e-mail information when the UPS A has gone on
battery backup and when the batteries are low. When the batteries are low, the HMI safely shuts
down to avoid abrupt power interruption. To enable this communication, a link between UPS A
and the primary touchscreen HMI is established. This link is a serial connection between the
DB-9 serial port connection on the UPS and the DB-9 serial port connection on the HMI. Since
distances between the HMI and UPS may exceed serial cable distances, a pair of RS-232 to
RS-485 converters are installed at each end to accommodate the cabling distance through the
switchgear.
1.3.19 RS-232 to RS-485 converter
This device converts RS-232 signals to RS-485 signals. This is required to support the cable
lengths in the switchgear. RS-232 imposes a distance limitation of only 15 meters. RS-485 can
transmit data over distances up to 1.2 km.
1.3.20 Entellisys System Test Kit
The Entellisys System Test Kit is a portable test instrument designed for field testing of the
Entellisys Low-Voltage Switchgear system.
The test kit includes the following features:
• Simulate power-line characteristics for a single circuit breaker in the Entellisys Low-Voltage
System
• Verify the function/operation of the protection system
• Overcurrent protection tests – long time, short time, instantaneous and ground fault
protection tests
• Single point relay protection tests (overvoltage, undervoltage, over frequency, under
frequency, power reversal and phase loss, high current test)
• Verify the calibration of the trip time current curve
• Verify the operation of the circuit breaker actuation in “Trip mode”
• Perform tests without trips in “No Trip mode”
• Ground Fault Defeat function provides temporarily suspension of all ground fault protection
in the system
• Automatically retrieves system configuration for increased productivity
• Displays a summary of all protection configuration
• Saves test results to be reviewed later
• Windows Interface for ease of use
• Operation from 120 Vac
For more information, see DEH-233 Entellisys Low Voltage Switchgear System Test Kit User
Manual.
1.3.21 Clamp circuit
The clamp circuit is an intermediary device between the CTs with 150ampere and 400ampere
ratings only. The clamp circuit protects the Messenger from large current outputs from the CTs.
The clamp circuit is installed in the circuit breaker compartment on the left-hand side sheet.
System architecture24
2Specifications
2.1 Environmental
Storage/shipping temperatures
–40 to 85° C
Operating temperatures
0 to 40° C ambient, indoor use
Humidity
5% to 95%, non-condensing, indoor use
2.2 Type tests
Tests are split into two categories:
• EntelliGuard Messenger Tests – the primary protection control element
UL Listed – Low Voltage AC Power Circuit Breaker Trip Unit - E-48428
FCC Class A listed
Specifications26
3Basic control
Entellisys allows users to control EntelliGuard circuit breakers from the HMI. A circuit breaker
may be commanded to open, close or trip. To locate or confirm the circuit breaker shown on the
HMI screen matches the physical circuit breaker, the locator LED on each EntelliGuard
Messenger can be set to flash for 10 or 30 seconds.
3.1 Controlling circuit breakers
To control a circuit breaker, navigate to the Breaker Status screen and click Control as shown in
Figure 3-1. The Breaker Control screen appears. The Breaker Control screen resembles
Figure 3-2 when the circuit breaker is open. The Breaker Control screen resembles Figure 3-3
when the circuit breaker is closed.
Figure 3-1 Breaker Status screen
3
Controlling circuit breakers27
Figure 3-2 Breaker Control screen for open circuit breaker
3
Figure 3-3 Breaker Control screen with closed circuit breaker
Basic control28
3.2 Block other HMIs
Any HMI that is designated as a Local HMI can block other HMIs from operating circuit breakers.
To designate an HMI as local, click the Modbus Security tab under the Maintenance menu.
When the check box on that screen is checked, the HMI is the Local HMI.
To block other HMIs from the local HMI, click the Control button under the Breaker Status
screen. In the Breaker Control screen there is a check box to Block Other HMIs.
Only Local HMIs have the ability to block other HMIs. If the Block Other HMIs check box is grayed
out, it is not setup as a Local HMI.
CAUTION:When controlling circuit breakers through a local HMI it is recommended that users
block all HMIs to prevent remote circuit breaker control. This step is in addition to normal
lock-out tag-out procedures when applicable.
3.3 Open circuit breaker (electrically operated circuit
breakers only)
To open a circuit breaker, click OPEN BREAKER on the Breaker Control screen. A dialog box
appears for verification that the circuit breaker should be opened. Click Yes to open the circuit
breaker. Once the open breaker command is verified, the EntelliGuard Messenger uses the
Shunt Trip to actually open the circuit breaker.
3
If the open breaker command is successful, the circuit breaker opens and the Current State of
the circuit breaker on the Breaker Control screen changes from Closed to Open. If the circuit
breaker does not open, examine the Sequence of Events. One of the following events may be
present:
• Attention Breaker Open Failed Shunt Trip
• Note Messngr Reports CPUA (or B) Command Timed Out
See Table A-2 for more information.
3.4 Close circuit breaker (electrically operated circuit
breakers only)
To close a circuit breaker, click CLOSE BREAKER on the Breaker Control screen. A dialog box
appears for verification that the circuit breaker should be closed. Click Yes to close the circuit
breaker. Once the close breaker command is verified, the EntelliGuard Messenger uses the Close
Coil to actually close the circuit breaker.
Block other HMIs29
If the close breaker command is successful, the circuit breaker closes and the Current State of
the circuit breaker on the Breaker Control screen changes from Open to Closed. If the circuit
breaker does not close, examine the Sequence of Events. One of the following events may be
present:
• Attention Breaker Close Failed
3
• Breaker Close Command Rejected Breaker Locked Out
• Note Messngr Arbitrated Command From CPUA (or B)
• Note Messngr Reports CPUA (or B) Command Timed Out
See Table A-2 for more information.
3.5 Trip circuit breaker
To trip a circuit breaker, click TRIP BREAKER on the Breaker Control screen. A dialog box
appears for verification that the circuit breaker should be tripped. Click Yes to trip the circuit
breaker. Once the trip breaker command is verified, the EntelliGuard Messenger uses the Flux
Shifter to actually trip the circuit breaker.
If the trip breaker command is successful, the circuit breaker trips and is locked out, and the
Current State of the circuit breaker on the Breaker Control screen changes from Closed to
Open-tripped. If the circuit breaker does not trip, examine the Sequence of Events. One of the
following events may be present:
• Attention Breaker Trip Failed Flux Shifter
• Note Messngr Reports CPUA (or B) Command Timed Out
See Table A-2 for more information.
3.6 Locator LED
To turn on the locator LED for 10 or 30 seconds, click 10 Seconds or 30 Seconds on the Breaker
Control screen. The locator LED on the particular EntelliGuard Messenger blinks for the
appropriate length, making identification easy.
3.7 Troubleshooting
Breaker Control screen only shows Trip option
• Open and close commands are only available for electrically operated circuit breakers.
Breaker Control screen shows Open, Close and Trip options at the same time
• Circuit breaker contact position is unknown.
Breaker control screen appears grayed out
• User does not have permissions to control circuit breakers.
Breaker does not open when command is issued
• Verify remote racker is not in.
Basic control30
4Metering
Entellisys provides a number of metering quantities, including RMS current and voltage,
demands, energy values, power factors, and harmonic data. There are four levels of metering
available: basic metering, expanded metering, demand metering, and advanced metering.
4.1 Basic metering
Basic metering is always available in Entellisys (i.e., it is not an optional feature). Basic metering
includes RMS current per phase (I
Entellisys provides line-to-neutral (V
delta PTs, Entellisys provides line-to-line voltages only.
The RMS voltages and currents are averages over one second (nominally 60 cycles of the
fundamental power system frequency at 60 Hz) and include harmonics.
4.2 Expanded metering
, IB, IC and IN) and RMS voltage per phase. For wye PTs,
A
, VB and VC) and line-to-line (VAB, VBC and VCA) voltages. For
A
4
Expanded metering (also referred to as detailed metering) is an optional feature in Entellisys.
Expanded metering can be enabled for each circuit breaker, up to the maximum number of
purchased expanded metering options. With the expanded metering option enabled, Entellisys
provides the following quantities:
• Positive watt-hours, per phase and total
• Negative watt-hours, per phase and total
• Positive var-hours, per phase and total
• Negative var-hours, per phase and total
• Apparent VA-hours, per phase and total
• Real power (watts) per phase and total
• Reactive power (vars) per phase and total
• Apparent power (VA) per phase and total
• Power factor per phase and total
• Minimum power factor, including date and time, per phase and total
• Maximum power factor, including date and time, per phase and total
Per phase quantities are only available for wye connected systems.
Watt-hours, var-hours, and VA-hours are sums starting from when the option was last applied,
or since the last time the values were reset through the HMI.
Real, reactive, and apparent power quantities are averages over one second (nominally
60 cycles of the fundamental power system frequency at 60 Hz) and include harmonics. Power
factors are calculated by dividing real power by apparent power.
Basic metering31
Watts and watt-hours are positive when the current is flowing from line to load and negative
when the current is flowing from load to line. Vars and var-hours are positive when the current is
lagging the voltage and negative when the current is leading the voltage.
The power factor is positive (i.e., lagging) when watts and vars have the same sign and negative
when watts and vars have the opposite sign. Minimum and maximum comparisons are done
based on magnitudes (e.g., a power factor of –0.866 is greater than a power factor of 0.707).
4
4.3 Demand metering
Demand metering is an optional feature in Entellisys. Demand metering can be enabled for
each circuit breaker, up to the maximum number of purchased demand metering options. When
the demand metering option is enabled, Entellisys provides the following quantities:
• All quantities available with the expanded metering option
• Previous interval kilowatt (kW) demand
• Maximum kW demand
• Previous interval kilovar (kvar) demand
• Maximum kvar demand
• Previous interval kVA demand
• Maximum kVA demand
• Demand logging – kWh, kvarh, kW demand, kvar demand, power factor
Per phase quantities are only available for wye connected systems.
Demands are averages over a demand interval. Entellisys supports both block and rolling
demand intervals:
Table 4-1 Demand interval and subinterval combinations supported in Entellisys
Subintervals per
interval
1 (block demand)Xxxxxxxxxxx
2xxxxxxxx
3xxxxxx
4xxxx
5xxxxx
6xxxx
Subinterval length, minutes
1234561015203060
10xxxx
12xx
xxx
Metering32
For block demand, Entellisys calculates the average demand over the duration of the demand
interval. For rolling demand, Entellisys calculates the average demand over the previous N
subintervals, where N is the number of subintervals per demand interval. This is done at the end
of each demand subinterval. Demand intervals are synchronized to the hour boundary. For
example, if the demand interval or subinterval length is 15 minutes, the demand intervals end
on the hour and at 15, 30, and 45 minutes past the hour.
The programmed interval length (block demand) or subinterval length and the number of
subintervals per demand interval apply to all circuit breakers at which demand metering is
enabled.
Demand log entries are added at the end of each demand interval or subinterval.
4.4 Advanced metering
Advanced metering (also referred to as harmonics metering) is an optional feature in Entellisys.
Advanced metering can be enabled for each circuit breaker, up to the maximum number of
purchased advanced metering options. When the advanced metering option is enabled,
Entellisys provides the following quantities:
• All quantities available with the demand metering option
• K factor for each current phase
4
• Voltage Total Harmonic Distortion (VTHD) for each phase
• Current Total Harmonic Distortion (ITHD) for each phase
• Frequency spectrum (magnitude only) for each voltage and current phase
Entellisys samples at 64 samples per cycle, so it will display the up to the 31
st
harmonic.
Advanced metering33
4.5 Metering accuracy
Table 4-2 shows the metering accuracy for Wh, varh, VAh, W, var, and VA under the following
conditions:
• Nominal frequency
• Nominal voltage
4
• Power factor of 0.85 to 1.00 for Wh and VAh
• Power factor of 0.00 to 0.15 for varh
Table 4-2 Metering accuracy for Wh, varh, VAh, W, var, and VA
Current (percent of nominal CT rating)Accuracy (percent of reading, includes
current and voltage sensors)
10%± 5.0%
30%± 4.5%
50%± 4.0%
75%± 3.0%
85-100%± 2.0%
Table 4-3 shows the voltage accuracy at nominal frequency:
Table 4-3 Voltage accuracy at nominal frequency
Current (percent of nominal PT rating)Accuracy (percent of reading, includes
voltage sensors)
50%± 2.0%
75%± 1.5%
85-100%± 0.8%
Table 4-4 shows the current accuracy at nominal frequency:
Table 4-4 Current accuracy at nominal frequency
Current (percent of nominal CT rating)Accuracy (percent of reading, includes
current sensors)
10%± 3.5%
30%± 3.25%
50%± 2.75%
75%± 1.75%
85-100%± 0.8%
Metering34
4.6 Setup
The setup required for metering falls into four basic categories: basic configuration, options,
programmable parameters, and meter distribution. Each is described in more detail below.
4.6.1 Basic configuration
Much of the basic configuration information necessary to ensure that metering operates
correctly is required for other functions, such as overcurrent functions and relays, as well; this
information is given in another section. It will be outlined here, however, as an introduction.
For Entellisys to correctly calculate all metering quantities that require current, it needs to know
the sensor rating for each circuit breaker. This information is stored in the Compartment ID
button that is connected to each Messenger. Entellisys also needs to have the current flow
direction for each circuit breaker.
For Entellisys to correctly calculate all metering quantities that require voltage, it needs to know
the potential transformer (PT) configuration (i.e., nominal voltage and whether it is a wye or
delta) for the circuit breaker that is supplying the voltage information. Entellisys does not require
PTs at each circuit breaker, so the voltage information supplied by one circuit breaker can be
used for calculations for other circuit breakers. See PT Throw-Over on page 99
information.
To view the frame and CT ratings, power flow direction, PT configuration, and reference PT for
each circuit breaker, click Metering & Waveforms on the User Settings screen and then click
Metering. The Metering options for the Metering & Waveforms screen are shown in Figure 4-1.
NOTE:Power flow direction is set by GE during factory configuration. It cannot be set by the
user.
4
for more
Setup35
Figure 4-1 Configuration information for metering
4
Metering36
4.6.2 Options
The three metering options (expanded, demand, and advanced) are described in the previous
sections. The number of each type of metering option purchased is specified in the option string
downloaded to the Entellisys CPU. To view the number of each type of option available, click the
Options tab on the Maintenance screen. The Options tab of the Maintenance screen is shown in
Figure 4-2.
Figure 4-2 Entellisys options
4
4.6.3 Programmable parameters
The only programmable parameters for metering are the demand interval or subinterval length,
and the number of subintervals per interval. To set these parameters, click Metering & Waveforms on the User Settings screen and then click Demand. The Demand parameters on
the Metering & Waveforms screen are shown in Figure 4-3.
Setup37
4.6.4 Meter distribution
One of the unique features of Entellisys is that meters can be moved from one circuit breaker to
another with just a few clicks. To change the placement of meters, click Metering & Waveforms
on the User Settings screen and then click Meter Distribution. The Meter Distribution
parameters on the Metering & Waveforms screen are shown in Figure 4-4.
4
NOTE:When a meter is removed from a circuit breaker, all data accumulated at that circuit
breaker (e.g., maximum demands, demand log information, and energy values) are cleared.
Because all metering information available with the expanded metering option is also available
with the demand metering option, and all metering information available with the demand
metering option is also available with the advanced metering option, it does not make any
sense to enable more than one meter type for a given circuit breaker. The HMI prevents the
enabling of more than one meter type for a given circuit breaker. The HMI also prevents the
enabling of more meters than the number of metering options purchased.
Figure 4-3 Configuring demand calculations
Metering38
Figure 4-4 Meter distribution
4
Setup39
4.7 Usage
4.7.1 Viewing basic metering data
Basic metering quantities (i.e., RMS voltage and current) are typically available on the one-line
4
diagram, although this depends on how the one-line diagram is configured. Figure 4-5 shows a
one-line diagram that displays the RMS currents at each circuit breaker and the RMS voltages at
the main bus.
Figure 4-5 One-Line diagram
To view all metering data, click the circuit breaker of interest in the one-line diagram. The
Breaker Status screen appears, as shown in Figure 4-6.
The Breaker Status screen displays information about all aspects of the circuit breaker. However,
in this section we are only concerned with metering data (i.e., the basic metering data [phase
currents and phase voltages]) and the buttons for navigating to the screens that display
optional metering data.
Metering40
Figure 4-6 Breaker Status screen
4
4.7.2 Viewing demand metering data
To view the Demand Metering screen, click Demand Metering on the Breaker Status screen.
The Demand Metering screen is shown in Figure 4-7.
The method for calculating previous interval and maximum demands and the function of the
demand log are described above.
NOTE:The Demand Metering button is only active if the Demand Metering option is enabled at
that circuit breaker.
In addition to viewing previous interval and maximum demands, demand log files can also be
viewed. To view demand log files, click View on the Demand Metering screen. A demand log file
is shown in Figure 4-8.
Usage41
Figure 4-7 Demand Metering screen
4
Figure 4-8 Demand log viewer
Metering42
The demand log shows the demand, power factor, and energy use by the system over time. To
view the details of the log (actual date and time at the top of the window and specific values at
the far left of the window) at a given time move the cursors by dragging the sliding bars at the
top of the window.
The Save to USB button saves the demand log file to the USB drive. The Config button provides
setup information, such as the line colors and the order in which the data appear, for the
demand log viewer. A demand log viewer configuration file is shown in Figure 4-9.
Figure 4-9 Demand log viewer configuration
4
The Demand Metering screen provides buttons that reset the demand values and the demand
logs.
The Reset Demand button resets the demand for the circuit breaker that is currently being
viewed; the Reset All Bkrs button resets the demand for all circuit breakers.
The Clear Log button resets the demand log for the circuit breaker that is currently being
viewed; the Clear All Bkrs button resets the demand logs for all circuit breakers. Entellisys keeps
track of how many times the demands and the demand logs have been reset, as well as the
date and time of the last resets.
Usage43
4.7.3 Viewing detailed metering data
To view the Detailed Metering screen, click Detailed Metering on the Breaker Status screen. The
Detailed Metering screen is shown in Figure 4-10.
Figure 4-10 Detailed Metering screen
4
NOTE:The Detailed Metering button is only active if the Expanded Metering option is enabled
for that circuit breaker. A description of the quantities available in the Detailed Metering screen
is given above.
The Clear Energy button resets the Real, Reactive, and Apparent energy values, as well as the
Minimum and Maximum Power Factors, for the circuit breaker currently being viewed.
The Clear All Bkrs button resets the energy and power factor values for all the circuit breakers.
Entellisys keeps track of how many times the energy values have been reset, as well as the date
and time of the last resets.
Metering44
4.7.4 Viewing harmonics metering data
To view the Harmonics Metering screen, click Harmonics Metering on the Breaker Status
screen. The Harmonics Metering screen is shown in Figure 4-11.
Figure 4-11 Harmonics Metering screen
4
NOTE:The Harmonics Metering button is only active if the Harmonics Metering option is
enabled for that circuit breaker.
To view the frequency spectra of the voltages and currents, click Harmonics Analysis on the Harmonics Meeting screen. Sample frequency spectra are shown in Figure 4-12.
Usage45
Figure 4-12 Frequency spectra for currents
4
A description of the quantities available in the Harmonics Metering screen is given above.
4.8 Troubleshooting
Current reads zero or dashes
• Verify that the Messenger is communicating to the CPU in the System Health screen. See
Monitoring system health on page 179
• Verify that the frame and CT ratings are properly configured. This information is available on
the Metering & Waveforms menu. See Basic configuration on page 35
• Verify the current exceeds 1% of CT rating. The system will zero the current if below 1%. To
verify this, trigger a waveform manually. The actual current will be displayed on the
waveform.
Voltage reads zero
• Verify that the circuit breaker has a source for voltage data and that the source has a valid
PT assigned to it by clicking Metering on the Metering & Waveforms screen. See Basic
configuration on page 35. Also see PT Throw-Over on page 99 for more information.
Detailed, Demand, or Advanced metering buttons are grayed out
• Verify that the corresponding option has been assigned to that circuit breaker. See Options
on page 37.
for more information.
.
Metering46
5Single point functions
⎠
⎝
5.1 Overcurrent protection
The Entellisys Low-Voltage Switchgear system provides four different kinds of protection: Long
Time (LT), Short Time (ST), Instantaneous Overcurrent (IOC) and Ground Fault (GF). The system
provides overcurrent protection by monitoring the phase currents at each circuit breaker. When
an overcurrent condition is detected, the system opens the circuit breaker.
There are two levels of overcurrent protection in the Entellisys system. The first level is provided
by the Entellisys CPU, and is based on phase-current data provided by each Messenger. The
parameters for these functions are set by the customer through the HMI (except for long time
pickup). The individual Messengers, based on local phase-current data, provide the second level.
The parameters for these overcurrent functions are fixed according to the safe operating region
for a given circuit breaker and are not programmable by the customer (except for long time
pickup).
The system rejects any parameter input that is not valid or that places the system in an unsafe
or inconsistent state. The system performs a range-checking operation on its programmed
settings and does not allow a setting that exceeds the circuit breaker's design limit, safe
operation, or the range specified by the applicable standard.
5
5.1.1 Long Time Overcurrent protection
There are two levels of Long Time (LT) Overcurrent Protection in the Entellisys system. The first
level is provided by the Entellisys CPU. The second level is provided by the Messenger.
2
T Long Time Overcurrent Protection curves
I
2
The equation for the I
2
I
RMS
⎞
⎛
⎜
=×
⎟
C
The parameters in this equation are defined as:
T = Time to trip in seconds.
C = LT current setting in amps and is equal to the Rating Switch value times the LT pickup
multiplier (see Table 5-1).
K = LT delay band constant in seconds, user adjustable.
I
= Value of the fault current in amps.
RMS
The Entellisys system provides four long time delay band settings. This selection defines the
value of the constant K in the LT equation.
T Long Time function limit is:
KT
Overcurrent protection47
5.1.1.1 Accuracy
The following long time delay band selections are available:
• Band 1: K = 108 seconds
• Band 2: K = 216 seconds
• Band 3: K = 432 seconds
• Band 4: K = 900 seconds
The fixed LT Overcurrent Protection delay setting at the Messenger is Band 4 (K = 900 s).
5
Pickup accuracy is ±10% over the entire protection range.
5.1.1.2 Setup
The LT Pickup setting is set with a rotary switch at the Messenger. This setting applies to the LT
protection provided by the Messenger and the protection provided by the Entellisys CPU. The
positions of the rotary switch and LT Pickup settings are shown in Table 5-1.
Table 5-1 Rotary switch positions and LT pickup settings
The delay for the LT protection provided by the Messenger is not user-programmable; it is fixed
according to the safe operating region for the circuit breaker controlled by the given Messenger.
The delay for the LT protection provided by the Entellisys CPU is set in the HMI as shown in
Figure 5-1.
Single point functions48
Figure 5-1 Setting Delay Band for LT protection for Breaker 2
5
5.1.1.3 Usage
The LT Overcurrent Protection function picks up when the current value for any phase is above
the LT Pickup setting.
LT pickup, trip, and dropout events are recorded in the Entellisys Sequence of Events log.
Waveforms and fault reports are also captured on an LT trip event and can be viewed from the
Sequence of Events log.
Overcurrent protection49
5.1.2 IOC/Short Time Overcurrent protection
There are two levels of Short Time (ST) Overcurrent Protection in the Entellisys system. The first
level is provided by the Entellisys CPU and is based on phase-current data provided by each
Messenger. The parameters for this function are user-adjustable through the HMI. The second
level is provided by the Messenger. The parameters for this overcurrent function are not
user-programmable; they are fixed based on the safe operating region for the circuit breaker
controlled by the given Messenger.
5.1.2.1 Short Time Overcurrent protection curves
5
There are seven ST delay bands available in Entellisys:
For 60 Hz systems
Band 1: 0.025 sec < T < 0.092 sec (see NOTE)
Band 2: 0.058 sec < T < 0.158 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.167 sec < T < 0.267 sec
Band 5: 0.217 sec < T < 0.317 sec
Band 6: 0.283 sec < T < 0.383 sec
Band 7: 0.400 sec < T < 0.500 sec.
For 50 Hz systems
Band 1: 0.030 sec < T < 0.095 sec (see NOTE)
Band 2: 0.060 sec < T < 0.160 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.170 sec < T < 0.270 sec
Band 5: 0.220 sec < T < 0.320 sec
Band 6: 0.280 sec < T < 0.380 sec
Band 7: 0.400 sec < T < 0.500 sec
NOTE:Band 1 is not intended to be selective with Band 3. The actual fault clearing time
depends on the energy content of the fault current.
2
Entellisys also provides an I
2
I
RMS
C
⎞
⎟
KT
=×
⎠
⎛
⎜
⎝
Where:
T curve option for ST, the equation for which is given below:
T = time to trip in seconds
K = 18 seconds
C = LT pickup setting, in amps
= fault current, in amps
I
RMS
Single point functions50
5.1.2.2 Accuracy
The I2T option is available with each of the seven delay bands listed above. Note that the trip
times will not be shorter than the values listed above for the delay bands, even when the I
curve is selected. For example, suppose ST band 6 (60 Hz) is selected and I
fault where (I
/C) is 4.0, the circuit breaker will trip according to the I2T curve. In this case the
RMS
system will initiate a trip after approximately 1.1 seconds. On a fault where (I
system will not follow the I
2
T curve and will instead initiate a trip according to the constant-time
2
T is enabled. On a
/C) is 10.0, the
RMS
part of the trip curve (i.e., after 0.283 seconds). In this case, if the system followed the I
2
T
2
T curve,
the trip time would have been only 0.18 seconds.
5.1.2.3 Setup
Pickup accuracy is ±10% over the entire protection range
The setup required for ST protection is done in the HMI and at the Messenger. There are three
options configured at each Messenger that control the operation of Short Time and
Instantaneous overcurrent protection:
• Short Time option
• Instantaneous option
• Switchable Short Time/Instantaneous option
If the Short Time option or the Instantaneous option (or both) is enabled, the state of the
Switchable ST/IOC option is ignored. The Messenger and Entellisys CPU perform the protection
functions specified by the Short Time and Instantaneous options.
If the Short Time and Instantaneous options are disabled and the Switchable ST/IOC option is
enabled, the Messenger defaults to performing Short Time and digital Instantaneous functions
until instructed otherwise by the Entellisys CPU. In this case, the Messenger does not perform
the analog Instantaneous function. The Entellisys CPU instructs the Messenger to turn on or off
Short T ime.
5
Overcurrent protection51
The operation of the Messenger and Entellisys CPU based on the state of the protection options
is summarized in Table 5-2 below:
Table 5-2 Protection options and operation of Entellisys CPU and Messenger
ST Option
(Messenger
config)
EnabledEnabledDon’t careNA – CPU will
IOC Option
(Messenger
config)
Switchable
ST/IOC
Option
(Messenger
config)
5
EnabledDisabledDon’t careNA – CPU has
DisabledEnabledDon’t careNA – CPU sets
DisabledDisabledDisabledNot a valid
Options at
Entellisys CPU
have ST will set
Messenger IOC
ST only
Messenger IOC
state
Notes
CPU: performs ST and sets Messenger’s IOC at
user setting.
Messenger: performs ST at max setting;
Messenger has analog IOC at max, digital IOC at
user setting. CPU cannot change Messenger
protection options.
CPU: performs ST at user setting.;
Messenger: performs ST at max setting. No
analog or digital IOC. CPU cannot change
Messenger protection options.
CPU: sets Messenger’s IOC at user setting.
Messenger has analog IOC at max, digital IOC at
user setting. CPU cannot change Messenger
protection options.
CPU: performs ST at default setting or user
settings if they have been changed.
Messenger: performs ST at max setting, digital
IOC at max setting. No analog IOC. CPU cannot
change Messenger protection options.
DisabledDisabledEnabledCPU not
operating
ST ON, IOC ONCPU: performs ST and IOC at user setting.
ST ON, IOC OFF CPU: performs ST at user setting.
ST OFF, IOC ON CPU: sets Messenger’s IOC at user setting.
ST OFF, IOC OFF
Invalid
command
Messenger: performs ST at max setting;
Messenger performs digital IOC at max or
previous user setting. No analog IOC.
Messenger: performs ST at max setting, digital
IOC at user setting. No analog IOC.
Messenger: performs ST at max setting. IOC can
only be turned OFF if ST is ON.
Messenger: performs digital IOC at user setting.
No analog IOC. ST can only be turned OFF if IOC
is ON.
Messenger: does not change protection
functions; current ST and IOC options and
settings continue to run.
Single point functions52
Entellisys limits the maximum Instantaneous Overcurrent Pickup Setting (P
) Multiplier based
IOC
on frame type and whether or not Short Time protection is enabled. This relationship is shown
for EntelliGuard circuit breakers in Table 5-3 below:
Table 5-3 Maximum P
Breaker Frame
Size
8001510
16001510
20001510
32001310
400099
500077
IOC
Maximum P
Short Time
IOC
with
Maximum P
Short Time
without
IOC
Parameters such as IOC pickup, ST pickup, curve type and delay bands for Short Time
protection are set in the HMI, as shown in Figure 5-2.
Figure 5-2 Setting parameters of IOC/ST protection for Breaker 2
5
Overcurrent protection53
5.1.2.4 Usage
ST Overcurrent Protection goes into pickup when the current in any phase is above the ST
pickup setting. ST pickup, trip, and dropout events are recorded in the Entellisys Sequence of
Events log. Waveforms and fault reports are also captured on an ST trip event, and can be
viewed from the Sequence of Events log.
The Entellisys system provides instantaneous overcurrent protection by tripping the circuit
breaker with no intentional delay when the sensed input current exceeds the programmed IOC
threshold. IOC trip events are recorded in the Entellisys Sequence of Events log. Waveforms and
fault reports are also captured on an IOC trip event, and can be viewed from the Sequence of
5
Events log.
5.1.3 Ground Fault protection
There are two levels of Ground Fault (GF) Overcurrent Protection available in the Entellisys
system. The first level is provided by the Entellisys CPU. This function is optional, and its
parameters, including whether to trip the circuit breaker or activate an alarm on a fault, are
user-programmable. The second level is provided by the individual Messenger. This function is
also optional, but its parameters are not user-programmable; the pickup and delay are set to
the maximum allowed for a given configuration. Also, the GF function performed at the
Messenger only trips the circuit breaker; no GF alarm-only option is available.
5.1.3.1 Ground Fault protection curves
There are seven GF delay bands available in Entellisys:
For 60 Hz systems
Band 1: 0.025 sec < T < 0.092 sec (see NOTE)
Band 2: 0.058 sec < T < 0.158 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.167 sec < T < 0.267 sec
Band 5: 0.217 sec < T < 0.317 sec
Band 6: 0.283 sec < T < 0.383 sec
Band 7: 0.400 sec < T < 0.500 sec.
For 50 Hz systems
Band 1: 0.030 sec < T < 0.095 sec (see NOTE)
Band 2: 0.060 sec < T < 0.160 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.170 sec < T < 0.270 sec
Band 5: 0.220 sec < T < 0.320 sec
Band 6: 0.280 sec < T < 0.380 sec
Band 7: 0.400 sec < T < 0.500 sec
Single point functions54
NOTE:Band 1 is not intended to be selective with Band 3. The actual fault clearing time
depends on the energy content of the fault current.
2
Entellisys also provides an I
2
I
P
RMS
GF
⎞
⎟
⎟
⎠
KT
=×
⎛
⎜
⎜
⎝
T curve option for GF, the equation for which is given below:
5.1.3.2 Accuracy
5.1.3.3 Setup
Where:
T = time to trip in seconds
K = 18 seconds
PGF = GF pickup setting, in amps
= ground fault current, in amps
I
RMS
2
The I
T option is available with each of the seven delay bands listed above. Note that the trip
times will not be shorter than the values listed above for the delay bands, even when the I
curve is selected. For example, suppose GF band 6 (60 Hz) is selected and I
fault where (I
/PGF) is 1.5, the circuit breaker will trip according to the I2T curve. In this case
RMS
the system will initiate a trip after approximately 0.9 seconds. On a fault where (I
2
the system will not follow the I
T curve and will instead initiate a trip according to the
2
T is enabled. On a
RMS
2
T
/PGF) is 5.0,
constant-time part of the trip curve (i.e., after 0.283 seconds). In this case, if the system followed
2
the I
T curve, the trip time would have been only 0.08 seconds.
Pickup accuracy is ±10% over the entire protection range
Setup for GF protection is done in two places:
• GF option at the Messenger
5
• Delay Band trip options in the HMI
The Ground Fault Pickup Setting Multiplier is adjustable for each circuit breaker over the range
of 0.20 to 0.60, but is limited by sensor rating as shown in Table 5-4:
Table 5-4 Maximum Ground Fault pickup threshold
WavePro™ breakers
Sensor, I
150–20000.6
32000.37
40000.3
50000.24
CT
Maximum Ground Fault Pickup
Threshold (
× I
)
CT
Overcurrent protection55
There are two options configured at each Messenger for Ground Fault. The combinations of
Ground Fault options are listed in Table 5-5 below.
Table 5-5 Ground Fault options
GF Optio n at
Messenger
EnabledDon’t CareNA – CPU must
5
DisabledEnabledGround Fault Trip NoCPU performs GF at user setting. On
DisabledEnabledGround Fault
DisabledEnabledGround Fault OFF NoNo GF at Messenger or CPU
DisabledDisabledGround Fault OFF NoNo GF at Messenger or CPU
Switchable GF
Option at
Messenger
Settings at CPUUL Listed as a
GF Device?
YesMessenger and CPU perform GF; CPU at
have GF trip
function
NoCPU performs GF alarm function at user
Alarm Only
Notes
user setting, Messenger at max
power up, Messenger does not perform
GF. CPU must tell Messenger to begin
performing GF (at max setting).
settings, Messenger does not perform GF
The parameters for the GF protection provided by the Entellisys CPU can be set in the HMI as
shown in Figure 5-3.
Figure 5-3 Event generated for IOC trip
Single point functions56
5.1.3.4 Usage
The GF Protection function detects unintentional current flowing from a circuit to a conducting
path to ground. These currents are usually of a lower magnitude than the current set by the LT
pickup setting and would not normally be sensed by that protection function. GF protection is
performed by calculating the vector sum of the three phase currents in a three-wire system or
the vector sum of the three phase currents and the neutral in a four-wire, wye-system and
comparing this sum to a pickup threshold.
GF pickup, trip, and dropout events are recorded in the Entellisys Sequence of Events log.
Waveforms and fault reports are also captured on an GF trip event, and can be viewed from the
Sequence of Events log.
5.2 Single Point Relay protection
Entellisys system provides Single Point Protection Relay functions in three optional packages:
the Voltage Relays package, the Frequency and Reverse Power Relays package and the High
Current Relay package.
The Voltage Relays package includes the following functions:
• Undervoltage
5
• Overvoltage
• Phase Loss Protection
The Frequency and Reverse Power Relays package includes the following functions:
• Under Frequency
• Over Frequency
• Reverse Power Protection
The High Current Relay package includes the following function:
• High Current Protection
NOTE:Removing a relay package from a Messenger can cause any control scheme that
includes those relays to misoperate. See Options on page 37 for more details.
These protection relay functions run in addition to the standard overcurrent protection
functions and are performed at the Entellisys CPU only. No protection relay functions are
performed locally at the Messengers.
Each relay has two sets of pickup and delay settings, with the exception of the High Current and
High Resistance GF. One set is for tripping the circuit breaker and the other is for activating an
alarm. Therefore, a user can set one threshold for a trip condition and the other threshold for an
alarm condition. It is possible to enable or disable each relay function individually; for example,
it is possible to enable a relay alarm function but disable the trip function.
Single Point Relay protection57
Relay trips can be configured to use either the OPEN command (flux shifter open without bell
alarm activation) or the TRIP command (flux shifter open with bell alarm activation). The system
will not perform a relay function requiring voltage if there is no valid PT source for that
Messenger.
If a circuit breaker is opened (either through a OPEN or TRIP command) by a voltage relay, and
the circuit breaker is re-closed, Entellisys will re-open the circuit breaker within approximately
three seconds if the condition is still present.
5.2.0.1 Enabling Single Point Relay packages
Single Point Relay packages must be enabled for each circuit breaker before any relay can be
5
used individually on that circuit breaker. This is done by GE.
5.2.1 Undervoltage Relay
Entellisys executes the Undervoltage Relay function by comparing the voltage in each phase to
the nominal 1X value of the system voltage. For example, in a 120-V wye system, nominal 1X is
defined to be 120-V phase to neutral.
The relay can be in three states:
• Pickup – If the voltage in a set number of voltage phases (one, two or all three voltage
phases) is less than the pickup set point, the relay goes into pickup, and is said to enter
Pickup state
• Operate – If the relay stays in pickup state for a specified pick up delay time, the system
trips the appropriate circuit breaker or activates an alarm, and the relay is said to be in
Operate state
• Drop out – The relay drops out of pickup when the voltage exceeds 103% of the
programmed threshold. The relay is said to be in Drop out state.
For wye potential transformers, the Undervoltage Relay operates on line-to-neutral voltage. For
open delta potential transformers, the Undervoltage Relay operates on line-line voltage.
Entellisys uses RMS voltages in the calculations.
The Undervoltage Relay can function using both constant and inverse time curves.
Constant time function: If the constant time curve is selected, the system trips the appropriate
circuit breaker or activates an alarm if the phase voltage is less than the set point for the
specified time delay.
Trip time accuracy: Trip-time accuracy is
±0.1 second.
Single point functions58
Inverse time function: If the inverse time curve is selected, the system trips the appropriate
circuit breaker or activates an alarm according to the equation:
T =
The parameters in this equation are defined as:
T = operating time
D = delay setting
V = input voltage
V
pickup
Trip time accuracy: Trip time accuracy depends on the value of V/V
to 1, the larger the trip time error is for a given pickup error. For V/V
accuracy is
Blocking voltage option: A 'blocking voltage' user-defined input option is provided. The
Undervoltage Relay function is not performed if the blocking voltage option is enabled and the
voltages on all three phases are less than the blocking voltage setting. If the Undervoltage Relay
goes into pickup, and the voltages subsequently drop below the blocking voltage, the relay goes
out of pickup and the delay is reset.
Accuracy: Pickup accuracy is
D
()
VV-1
pickup
= pickup voltage = (set point) × (nominal voltage)
±10%. For V/V
= 0.5, the trip time accuracy is ±4%.
pickup
±2%.
. The closer that ratio is
pickup
= 0.8, the trip time
pickup
5
5.2.1.1 Setup
To set the Trip and Alarm settings for the Undervoltage Relay function
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
The remainder of this section discusses the relay parameters that can be set in the
Undervoltage section of the Relay Protection screen as shown in Figure 5-4.
5.2.1.2 Trip settings
Relay Enabled: Select Enabled to enable the relay.
Curve Type: Select either Constant time curve or Inverse time curve from the Curve Type
drop-down menu.
Pickup: Adjust the undervoltage pickup from 50% to 95% in increments of 1% from the Pickup
Setting drop-down menu.
Delay: Adjust the undervoltage delay from 0.5 to 600 seconds in increments of 0.5 seconds from
the Time Delay drop-down menu.
menu and click Undervoltage.
Single Point Relay protection59
Phase Requirement: Select from among the following options using the Phase Requirement
drop-down menu:
• Operate if any one phase is below the pickup threshold
• Operate if any two phases are below the pickup threshold
• Operate if all three phases are below the pickup threshold
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage.
Blocking Voltage Setting: Adjust the blocking voltage from 5% to 75% in increments of 1%
5
using the Setting drop-down menu in the Blocking Voltage section.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down menu. Options are Open and don't activate lockout and Trip and activate lockout.
5.2.1.3 Alarm settings
Relay Enabled: Select Enabled to enable the alarm relay.
Curve Type: Select either Constant time curve or Inverse time curve from the Curve Type
drop-down menu.
Pickup: Adjust the undervoltage pickup from 50% to 95% in increments of 1% from the Pickup
Setting drop-down menu.
Delay: Adjust the undervoltage delay from 0.5 to 600 seconds in increments of 0.5 seconds from the Time Delay drop-down menu.
Phase Requirement: Select from among the following options using the Phase Requirement
drop-down menu:
• Operate if any one phase is below the pickup threshold
• Operate if any two phases are below the pickup threshold
• Operate if all three phases are below the pickup threshold
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage.
Blocking Voltage Setting: Adjust the blocking voltage from 5% to 75% in increments of 1%
using the Setting drop-down menu in the Blocking Voltage section.
Single point functions60
Figure 5-4 Settings for Undervoltage Relay
5
5.2.1.4 Usage
Event logging
The following events are logged:
• Alarm Pickup Undervoltage – when the alarm function enters pickup
• Alarm Undervoltage – when the alarm function operates
• Alarm Dropout Undervoltage – when the alarm function drops out
• Pickup Undervoltage – when the trip function enters pickup
• Breaker Trip Undervoltage – when the trip function operates
• Dropout Undervoltage – when the trip function drops out
• Voltage Below Undervoltage Alarm Blocking Voltage – The voltages on all three phases have
dropped below the alarm only undervoltage blocking voltage threshold.
• Voltage Above Undervoltage Alarm Blocking Voltage – The voltage on at least one of the
three phases has exceeded the alarm only undervoltage blocking voltage threshold.
• Voltage Below Undervoltage Blocking Voltage – The voltages on all three phases have
dropped below the undervoltage blocking voltage threshold.
• Voltage Above Undervoltage Blocking Voltage – The voltage on at least one of the three
phases has exceeded the undervoltage blocking voltage threshold.
To view these events, click Sequence of Events on the Main Menu.
Single Point Relay protection61
5.2.2 Overvoltage Relay
The Entellisys system performs the Overvoltage Relay function by comparing the voltage in
each phase to the nominal 1X value of the system voltage. For example, in a 120-V wye system,
nominal 1X is defined to be 120-V phase to neutral.
The relay can be in three states:
• Pickup – If the voltage in a set number of voltage phases (one, two or all three voltage
phases) is greater than the pickup set point, the relay goes into pickup, and is said to enter
Pickup state
5
5.2.2.1 Accuracy
• Operate – If the relay stays in pickup state for a specified pick up delay time, the system
trips the appropriate circuit breaker or activates an alarm, and the relay is said to be in
Operate state
• Drop out – The relay drops out of pickup when the voltage drops below 97% of the
programmed threshold. The relay is said to be in Drop out state.
For wye potential transformers, the Overvoltage Relay operates on phase neutral voltage. For
open delta potential transformers, the Overvoltage Relay operates on line-line voltage.
Entellisys uses RMS voltages in the calculations.
The system trips the appropriate circuit breaker or activates an alarm if the voltage is greater
than the pick up set point for the specified time delay.
Pickup accuracy is ±2%.
5.2.2.2 Setup
To set the Trip and Alarm settings for the Overvoltage Relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
The remainder of this section discusses the relay parameters that can be set in the Overvoltage
section of the Relay Protection screen as shown in Figure 5-5.
5.2.2.3 Trip settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the overvoltage pickup from 105% to 125% in increments of 1% from the Pickup
Setting drop-down menu.
Delay: Adjust the overvoltage delay from 0.5 to 600 seconds in increments of 0.5 seconds from the Time Delay drop-down menu.
Phase Requirement: Select from among the following options using the Phase Requirement
drop-down menu:
• Operate if any one phase is below the pickup threshold
menu and click Overvoltage.
• Operate if any two phases are below the pickup threshold
• Operate if all three phases are below the pickup threshold
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
Single point functions62
5.2.2.4 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the overvoltage pickup from 105% to 125% in increments of 1% from the Pickup
Setting drop-down menu.
Delay: Adjust the overvoltage delay from 0.5 to 600 seconds in increments of 0.5 seconds from the Time Delay drop-down menu.
Phase Requirement: Select from among the following options using the Phase Requirement
drop-down menu:
• Operate if any one phase is below the pickup threshold
• Operate if any two phases are below the pickup threshold
• Operate if all three phases are below the pickup threshold
Figure 5-5 Settings for Overvoltage Relay
5
Single Point Relay protection63
5.2.2.5 Usage
Event logging
The following events are logged for the Overvoltage relay in the Entellisys HMI:
• Alarm Pickup Overvoltage – Alarm only overvoltage relay has entered pickup
• Alarm Overvoltage – Alarm only overvoltage relay has operated
• Alarm Dropout Overvoltage – Alarm only overvoltage relay has dropped out of pickup
• Pickup Overvoltage – Overvoltage relay has entered pickup
5
• Breaker Trip Overvoltage – Overvoltage relay has operated
• Dropout Overvoltage – Overvoltage relay has dropped out of pickup
To view these events, click Sequence of Events on the Main Menu.
5.2.3 Over Frequency Relay
The Entellisys System executes the Over Frequency Relay function by comparing the
fundamental frequency of the phase A voltage to the programmed pickup set point.
The relay can be in three states:
• Pickup – If the frequency of the phase A voltage is greater than the pickup set point, the
relay goes into pickup, and is said to enter Pickup state
• Operate – If the relay stays in pickup state for a specified pick up delay time, the system
trips the appropriate circuit breaker or activates an alarm, and the relay is said to be in
Operate state
• Drop out – The relay drops out of pickup when the frequency drops below 97% of the
programmed threshold. The relay is said to be in Drop out state.
The system trips the appropriate circuit breaker or activates an alarm if the frequency is greater
than the pickup set point for the specified time delay.
5.2.3.1 Accuracy
Single point functions64
Pickup accuracy is less than ±0.1 Hz. Trip time accuracy is ±0.1 seconds.
Blocking voltage option: A 'blocking voltage' user-defined input option is provided. The over
frequency relay function is not performed if the blocking voltage option is enabled and the
voltage is less than the blocking voltage. If the Over Frequency Relay goes into pickup, and the
voltages subsequently drop below the blocking voltage, the relay goes out of pickup and the
delay is reset.
5.2.3.2 Setup
The accuracy of the blocking voltage depends on the frequency deviation and is listed in
Table 5-6.
Table 5-6 Blocking voltage accuracy
Frequency DeviationBlocking Voltage Accuracy
0 Hz±2%
2 Hz±5%
4 Hz±7%
6 Hz±10%
8 Hz±13%
10 Hz±15%
To set the Trip and Alarm settings for the Over Frequency Relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down menu and click Over Frequency.
5
The remainder of this section discusses the relay parameters that can be set in the Over
Frequency section of the Relay Protection screen as shown in Figure 5-6.
5.2.3.3 Trip settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the over frequency pickup from 50 to 70 Hz in increments of 0.1 Hz from the
Pickup Setting drop-down menu.
Delay: Adjust the over frequency delay from 0.1 to 600 seconds in increments of 0.1 seconds from the Time Delay drop-down menu.
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage. If the option is enabled, the blocking voltage setting is 10% of the nominal
voltage.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
5.2.3.4 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the over frequency pickup from 50 to 70 Hz in increments of 0.1 Hz from the
Pickup Setting drop-down menu.
Delay: Adjust the over frequency delay from 0.1 to 600 seconds in increments of 0.1 seconds from the Time Delay drop-down menu.
Single Point Relay protection65
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage. If the option is enabled, the blocking voltage setting is 10% of the nominal
voltage.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
Figure 5-6 Settings for Over Frequency Relay
5
5.2.3.5 Usage
Single point functions66
Event logging
The following events are logged for the over frequency relay in the Entellisys HMI:
• Alarm Pickup Over Frequency – Alarm only over frequency relay has entered pickup.
• Alarm Over Frequency – Alarm only over frequency relay has operated.
• Alarm Dropout Over Frequency – Alarm only over frequency relay has dropped out of
pickup.
• Voltage Below Overfreq Alarm Blocking Voltage – The voltage has dropped below the alarm
only over frequency blocking voltage threshold.
• Voltage Above Overfreq Alarm Blocking Voltage – The voltage has exceeded the alarm only
over frequency blocking voltage threshold.
• Pickup Over Frequency – Over frequency relay has entered pickup.
• Breaker Trip Over Frequency – Over frequency relay has operated.
• Dropout Over Frequency – Over frequency relay has dropped out of pickup.
• Voltage Below Over Frequency Blocking Voltage – The voltage has dropped below the over
frequency blocking voltage threshold.
• Voltage Above Over Frequency Blocking Voltage – The voltage has exceeded the over
frequency blocking voltage threshold.
To view these events, click Sequence of Events on the Main Menu.
5.2.4 Under Frequency Relay
5.2.4.1 Accuracy
The Entellisys System executes the Under Frequency Relay function by comparing the
fundamental frequency of the phase A voltage to the programmed pickup set point.
The relay can be in three states:
• Pickup – If the frequency of the phase A voltage is less than the pickup set point, the relay
goes into pickup, and is said to enter Pickup state
• Operate – If the relay stays in pickup state for a specified pick up delay time, the system
trips the appropriate circuit breaker or activates an alarm, and the relay is said to be in
Operate state
• Drop out – The relay drops out of pickup when the frequency exceeds 103% of the
programmed threshold. The relay is said to be in Drop out state.
The system trips the appropriate circuit breaker or activates an alarm if the frequency is less
than the pickup set point for the specified time delay.
Pickup accuracy is less than ±0.1 Hz. Trip time accuracy is ±0.1 seconds.
Blocking voltage option: A 'blocking voltage' user-defined input option is provided. The under
frequency relay function is not performed if the blocking voltage option is enabled and the
voltage is less than the blocking voltage. If the Under Frequency Relay goes into pickup, and the
voltages subsequently drop below the blocking voltage, the relay goes out of pickup and the
delay is reset.
5
The accuracy of the blocking voltage depends on the frequency deviation and is listed in
Table 5-7.
Table 5-7 Blocking voltage accuracy
Frequency DeviationBlocking Voltage Accuracy
0 Hz±2%
2 Hz±5%
4 Hz±7%
6 Hz±10%
8 Hz±13%
10 Hz±15%
Single Point Relay protection67
5.2.4.2 Setup
To set the Trip and Alarm settings for the Under Frequency Relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
menu and click Under Frequency.
The remainder of this section discusses the relay parameters that can be set in the Under
Frequency section of the Relay Protection screen as shown in Figure 5-7.
5.2.4.3 Trip settings
5
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the under frequency pickup from 50 to 70 Hz in increments of 0.1 Hz from the
Pickup Setting drop-down menu.
Delay: Adjust the under frequency delay from 0.1 to 600 seconds in increments of 0.1 seconds from the Time Delay drop-down menu.
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage. If the option is enabled, the blocking voltage setting is 10% of the nominal
voltage.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
5.2.4.4 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the under frequency pickup from 50 to 70 Hz in increments of 0.1 Hz from the
Pickup Setting drop-down menu.
Delay: Adjust the under frequency delay from 0.1 to 600 seconds in increments of 0.1 seconds from the Time Delay drop-down menu.
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage. If the option is enabled, the blocking voltage setting is 10% of the nominal
voltage.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
Single point functions68
Figure 5-7 Settings for Under Frequency Relay
5
5.2.4.5 Usage
Event logging
While the relay is functional, the following events are logged for the under frequency relay in the
Entellisys CPU:
• Alarm Pickup Under Frequency – Alarm only under frequency relay has entered pickup.
• Alarm Under Frequency – Alarm only under frequency relay has operated.
• Alarm Dropout Under Frequency – Alarm only under frequency relay has dropped out of
pickup.
• Voltage Below Underfreq Alarm Blocking Voltage – The voltage has dropped below the alarm
only under frequency blocking voltage threshold.
• Voltage Above Underfreq Alarm Blocking Voltage – The voltage has exceeded the alarm only
under frequency blocking voltage threshold.
• Pickup Under Frequency – Under frequency relay has entered pickup.
• Breaker Trip Under Frequency – Under frequency relay has operated.
• Dropout Under Frequency – Under frequency relay has dropped out of pickup.
• Voltage Below Under Frequency Blocking Voltage – The voltage has dropped below the
under frequency blocking voltage threshold.
• Voltage Above Under Frequency Blocking Voltage – The voltage has exceeded the under
frequency blocking voltage threshold.
To view these events, click Sequence of Events on the Main Menu.
Single Point Relay protection69
5.2.5 Phase Loss Relay protection
Phase Loss is an optional relay that is part of the voltage relay package. The Entellisys system
performs Phase Loss Relay Protection by comparing the negative-phase sequence voltage to
the nominal 1X value of the system voltage.
For example, in a 120-V wye system, nominal 1X is defined as 120-V phase to neutral. The
negative-phase sequence voltage for the phase-to-phase voltages is used regardless of PT
configuration (i.e., delta or wye). The negative-phase sequence voltage for line-to-line is
calculated as follows:
5
V++=
1
()
3
2
aVVaV
1N
32
The parameters in these equations are defined as:
V
= negative phase sequence voltage
N
a = 1∠120
a2 = 1∠240
For ABC phase rotation, V1 = Vab, V2 = Vbc, V3 = V
For ACB phase rotation, V1 = Vab, V2 = Vca, V3 = V
o
o
ca
bc
The negative-phase sequence voltages are calculated for the fundamental (60 or 50 Hz)
component only.
The relay can be in three states:
• Pickup – If the negative-phase sequence voltage is more than the pickup set point, the relay
goes into pickup, and is said to enter Pickup state.
• Operate – If the relay stays in Pickup state for a specified pickup delay time, the system trips
the appropriate circuit breaker or activates an alarm, and the relay is said to be in Operate
state.
5.2.5.1 Accuracy
Single point functions70
• Drop out – The relay drops out of pickup when the negative-phase sequence voltage drops
below 97% of the programmed threshold. The relay is said to be in Drop out state.
The phase loss pickup setting can be adjusted from 8% to 50% in increments of 1%. The phase
loss delay setting can be adjusted from 0.5 second to 600 seconds in increments of 0.5 seconds.
Blocking voltage option: An optional blocking voltage is provided and, if enabled, is 5%. The
phase loss relay function is not performed if Blocking Voltage is enabled and the voltage on all
phases is less than the blocking voltage, in which case the system logs an event. If the phase
loss relay goes into pickup, and the voltage subsequently drops below the blocking voltage, the
relay goes out of pickup and the delay is reset. It is possible to suspend the relay through
FlexLogic.
Pickup accuracy is ±4%. Trip time accuracy is ±0.1 seconds.
5.2.5.2 Setup
To set the Trip and Alarm settings for the Phase Loss relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
The remainder of this section discusses the relay parameters that can be set in the Phase Loss
section of the Relay Protection screen as shown in Figure 5-8.
5.2.5.3 Trip settings
menu and click Phase Loss.
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the phase loss pickup from 8% to 50% in increments of 1% from the Pickup
Setting drop-down menu.
Delay: Adjust the phase loss delay from 0.1 to 600 seconds in increments of 0.5 seconds from the Time Delay drop-down menu.
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage. If the option is enabled, the blocking voltage setting is 5% of the nominal
voltage.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
5.2.5.4 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the phase loss pickup from 8% to 50% in increments of 1% from the Pickup
Setting drop-down menu.
Delay: Adjust the phase loss delay from 0.1 to 600 seconds in increments of 0.5 seconds from the Time Delay drop-down menu.
5
Blocking Voltage Enabled: Select Enabled in the Blocking Voltage section to enable the
blocking voltage. If the option is enabled, the blocking voltage setting is 5% of the nominal
voltage.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
Single Point Relay protection71
Figure 5-8 Phase Loss Relay settings
5
5.2.5.5 Usage
The phase rotation is set at the factory and cannot be changed by the user.
Phase Loss goes into pickup whenever the negative-phase sequence voltage is greater than the
pickup threshold set by the user. The Phase Loss Relay trips or sets off the alarm with the time
delay set by the user.
Event logging
The events generated by a Phase Loss Relay are:
• Alarm Pickup Phase Loss – Alarm only phase loss relay has entered pickup.
• Alarm Phase Loss – Alarm only phase loss relay has operated.
• Alarm Dropout Phase Loss – Alarm only phase loss relay has dropped out of pickup.
• Voltage Below Phase Loss Alarm Blocking Voltage – The voltages on all three phases have
dropped below the alarm only phase loss blocking voltage threshold.
• Voltage Above Phase Loss Alarm Blocking Voltage – The voltage on at least one of the three
phases has exceeded the alarm only phase loss blocking voltage threshold.
• Pickup Phase Loss – Phase loss relay has entered pickup.
• Breaker Trip Phase Loss – Phase loss relay has operated.
Single point functions72
• Dropout Phase Loss – Phase loss relay has dropped out of pickup.
• Voltage Below Phase Loss Blocking Voltage – The voltages on all three phases have dropped
below the phase loss blocking voltage threshold.
• Voltage Above Phase Loss Blocking Voltage – The voltage on at least one of the three phases
has exceeded the phase loss blocking voltage threshold.
To view these events, click Sequence of Events on the Main Menu.
5.2.6 Reverse Power Relay
The Entellisys system provides a Reverse Power Relay that prevents an open primary on a
transformer from back-feeding the magnetizing current. The system performs this function by
comparing the magnitude and direction of the power in each phase to the set point. If, on any
phase, the direction of the power is reversed and the magnitude of the power is greater than the
set point for the specified time delay, the system opens or trips the circuit breaker or activates
an alarm.
The relay can be in three states:
• Pickup – If the reverse power is more than the pickup set point, the relay goes into pickup,
and is said to enter Pickup state.
• Operate – If the relay stays in Pickup state for a specified pick up delay time, the system
trips the appropriate circuit breaker or activates an alarm, and the relay is said to be in
Operate state.
5
• Drop out – The relay drops out of pickup when the reverse power drops below 97% of the
The power reversal pickup setting can be adjusted from 10 to 990 kW, in steps of 10 kW. The
power reversal delay setting can be adjusted from 0.5 second to 600 seconds in increments of
0.5 seconds.
5.2.6.1 Accuracy
Pickup accuracy is ±4%. Trip time accuracy is ±0.5 seconds.
5.2.6.2 Setup
To set the Trip and Alarm settings for the Reverse Power Relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
The remainder of this section discusses the relay parameters that can be set in the Reverse
Power section of the Relay Protection screen as shown in Figure 5-9.
5.2.6.3 Trip settings
Relay Enabled: Select Enabled to enable the relay.
programmed threshold. The relay is said to be in Drop out state.
menu and click Reverse Power.
Pickup: Adjust the reverse power pickup from 10 to 990kW in increments of 10kW from the
Pickup Setting drop-down menu.
Single Point Relay protection73
Delay: Adjust the reverse power delay from 0.1 to 600 seconds in increments of 0.5 seconds
from the Time Delay drop-down menu.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
5.2.6.4 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the reverse power pickup from 10 to 990kW in increments of 10kW from the
Pickup Setting drop-down menu.
5
Delay: Adjust the reverse power delay from 0.1 to 600 seconds in increments of 0.5 seconds
from the Time Delay drop-down menu.
Open Trip: Select the command issued when the relay operates from the Open Trip drop-down
menu. Options are Open and don't activate lockout and Trip and activate lockout.
Figure 5-9 Reverse Power Relay settings
Single point functions74
5.2.6.5 Usage
The Reverse Power Relay goes into pickup whenever the direction of power, on any phase, is
reversed and the magnitude of the power is greater than the pickup threshold set by the user.
The Reverse Power Relay trips or sets off the alarm with the time delay set by the user.
Event logging
The following events are generated by the Reverse Power Relay:
• Alarm Pickup Reverse Power – Alarm only reverse power relay has entered pickup
• Alarm Reverse Power – Alarm only reverse power relay has operated
• Alarm Dropout Reverse Power – Alarm only reverse power relay has dropped out of pickup
• Pickup Reverse Power – Reverse power relay has entered pickup
• Breaker Trip Reverse Power – Reverse power relay has operated
• Dropout Reverse Power – Reverse power relay has dropped out of pickup
To view these events, click Sequence of Events on the Main Menu.
5.2.7 High Current Relay
The Entellisys system provides a High Current Relay. The system performs this function by
comparing each of the current phases to the programmed threshold. If any of the currents are
above the programmed threshold for more than the programmed delay, the system activates
an alarm. The High Current Relay cannot trip a circuit breaker.
5
5.2.7.1 Accuracy
5.2.7.2 Setup
The relay can be in three states:
• Pickup – If the current in any phase is more than the pickup set point, the relay goes into
pickup, and is said to enter Pickup state
• Operate – If the relay stays in pickup state for a specified pick up delay time, the system
trips the appropriate circuit breaker or activates an alarm, and the relay is said to be in
Operate state
• Drop out – The relay drops out of pickup when the current drops below 97% of the
programmed threshold. The relay is said to be in Drop out state.
The high current pickup relay can be adjusted from 50% to 200% of the Long Time Protection
pickup setting, in increments of 5%. The high current delay setting can be adjusted from 1 to 15
seconds in steps of 1 second. The relay can be suspended through Flex Logic.
Pickup accuracy is ±10%. Trip time accuracy is ±1 second.
To set the Alarm settings for the high current relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
menu and click High Current.
The remainder of this section discusses the relay parameters that can be set in the High Current
section of the Relay Protection screen as shown in Figure 5-10.
Single Point Relay protection75
5.2.7.3 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the high current pickup from 50% to 200% in increments of 5% from the Pickup
Setting drop-down menu.
Delay: Adjust the high current delay from 1 to 15 seconds in increments of 1 second from the
Time Delay drop-down menu.
Figure 5-10 High Current Relay settings
5
5.2.7.4 Usage
The High Current Relay goes into pickup when any of the currents are greater than the
programmed threshold. The high current relay sets off the alarm with the time delay set by the
user.
5.2.7.5 Event logging
The High Current Relay generates the following events:
• Alarm Pickup High Current – High current relay has entered pickup
• Alarm High Current – High current relay has operated
• Alarm Dropout High Current – High current relay has dropped out of pickup
To view these events, click Sequence of Events on the Main Menu.
Single point functions76
5.2.8 High Resistance Ground Fault Relay
The Entellisys system provides an optional High Resistance Ground Fault Detection (HRGF)
Function that is an alarm-only function that does not trip the circuit breaker.
The relay can be in three states:
• Pickup – If the ground current in any phase is more than the pickup set point, the relay goes
into pickup, and is said to enter Pickup state.
• Operate – If the relay stays in pickup state for a specified pick up delay time, the system
activates an alarm, and the relay is said to be in Operate state.
• Drop out – The relay drops out of pickup when the ground current drops below 97% of the
programmed threshold. The relay is said to be in Drop out state.
The HRGF pickup is programmable from 2.0 amps to 10.0 amps of ground current in steps of 0.1
amps. The delay setting is programmable from 0.5 to 5 seconds in steps of 0.1 second. A
constant time curve is used for HRGF. If the ground current is above the pickup threshold, the
system logs an event. If the ground current remains above the threshold for longer than the
delay setting, the system logs an event and activates an alarm.
5.2.8.1 Accuracy
Pickup accuracy is ±10%.
5
5.2.8.2 Setup
The HRGF relay is a per line-up option.
To set the Alarm settings for the HRGF relay
1. On the Main Menu, click User Settings, and then select Relay Protection.
2. On the Relay Protection screen, choose the circuit breaker number from the drop-down
menu and click High Resistance GF.
The remainder of this section discusses the relay parameters that can be set in the High
Resistance GF section of the Relay Protection screen as shown in Figure 5-11.
5.2.8.3 Alarm settings
Relay Enabled: Select Enabled to enable the relay.
Pickup: Adjust the HRGF pickup from 2 Amps to 10 Amps in increments of 0.1 Amp from the
Pickup Setting drop-down menu.
Delay: Adjust the HRGF delay from 0.5 to 5 seconds in steps of 0.1 second from the Time Delay
drop-down menu.
Ground Resistance: Adjust the Ground Resistance from 5 to 500 ohms in steps of 1 ohm from
the Ground Resistance drop-down menu.
Single Point Relay protection77
Figure 5-11 High Resistance GF settings
5
5.2.8.4 Usage
The High Resistance Ground Fault Relay goes into pickup if the ground current is above the
pickup threshold and generates an alarm if the ground current remains above the threshold for
longer than the delay setting.
5.2.8.5 Event logging
The HRGF relay generates the following events:
• Pickup High Resistance GF – when the alarm function enters pickup
• Alarm High Resistance GF – when the alarm function operates
• Drop out High Resistance GF – when the alarm function drops out
To view these events, click Sequence of Events on the Main Menu.
Single point functions78
5.3 Synch Check relay
The Synch Check function is used as a permissive for closed-transition automatic throw-over
control schemes.
Entellisys performs the synch check relay function by comparing the amplitude, phase and
frequency of the voltages in each of the three phases of the two selected source circuit
breakers.
NOTE:The Synch Check Relay function is not a per node option, but a per line up option.
Entellisys provides up to six synch check functions.
The following thresholds are used by the Synch Check relay:
Dead Bus Threshold: This user-programmable value represents the voltage for source 1 below
which a phase is considered dead.
Live Bus Threshold: This user-programmable value represents the voltage for source 1 above
which a phase is considered live.
5.3.1 Synch check status
Each synch check function provides the following status information:
Synchronous Live: Set to true if all three phases at both sources are above the live bus
threshold and are in synch (i.e., all three phases satisfy the programmed voltage, frequency, and
phase differential criteria) and is set to false otherwise.
Dead Source: If one or both sources are de-energized, the dead source selection permits closing
of the circuit breaker to by-pass the synch check measurements. The following Dead Source
criteria selections are available:
5
• None – Dead source function is disabled
• LV1 and DV2 – Voltage source 1 live and voltage source 2 dead
• DV1 and LV2 – Voltage source 1 dead and voltage source 2 live
• DV1 or DV2 – Voltage source 1 dead or voltage source 2 dead
• DV1 xor DV2 – One voltage source is dead, the other is live
• DV1 and DV2 – Both sources are dead
The Dead Source status is shown as true if the programmed dead bus configuration condition is
true.
Close: This status is set to true if Synchronous Live is true or Dead Source is true.
Each synch check function verifies that the two sources have the same PT primary voltage and
configuration (delta or wye). If both parameters are not the same for both sources, the CPU logs
an event and disables the synch check function.
Synch Check relay79
5.3.2 Setup
To set the settings for the Synch Check Relay
1. On the Main Menu, click User Settings, and then select Control.
2. On the Control screen, click Synch Check.
The remainder of this section discusses the parameters that can be set in the Synch Check
section of the Control screen as shown in Figure 5-12.
The following settings must be set for the Synch Check Relay:
5
5.3.2.1 Source voltages
Synch Check Function: Choose the synch check relay number from the Synch Check Function
drop-down menu.
Relay Name: Assign a name for identifying the relay.
Relay Enabled: Select Enable to enable the relay.
First: Select the circuit breaker number that provides the voltage for source 1 from the First drop-down menu in the Source Voltages menu group.
Second: Select the circuit breaker number that provides the voltage for source 2 from the
Second drop-down menu in the Source Voltages menu group.
5.3.2.2 Maximum differentials
Voltage: Adjust the maximum voltage differential allowed between source voltages for the
synch check function to operate from 0 to 90 V in steps of 0.5 V from the Voltage drop-down
menu in the Maximum Differentials menu group.
Frequency: Adjust the maximum frequency differential allowed between source voltages for
the synch check function to operate from 0 to 2 Hz in steps of 0.1 Hz from the Frequency
drop-down menu.
Phase: Adjust the maximum phase differential allowed between source voltages for the synch
check function to operate from 0 to 60 degrees in steps of 1 degree from the Phase drop-down
menu.
The Synch Check function applies a 3% hysteresis factor to the voltage, frequency, phase, live
bus and dead bus thresholds.
5.3.2.3 Source 1
Dead Bus Threshold: Adjust the threshold below which a phase is considered dead from 5 to
50% of the nominal voltage (line-neutral for wyes, line-line for deltas) in steps of 1% from the
Dead Bus Threshold drop-down menu in the Source 1 menu group.
Live Bus Threshold: Adjust the threshold above which a phase is considered live from 50% to
100% of the nominal voltage (i.e., the PT rating, line-neutral for wyes, line-line for deltas) in steps
of 1% from the Live Bus Threshold drop-down menu in the Source 1 menu group.
Single point functions80
5.3.2.4 Source 2
Dead Bus Threshold: Adjust the threshold below which a phase is considered dead from 5 to
50% of the nominal voltage (line-neutral for wyes, line-line for deltas) in steps of 1% from the
Dead Bus Threshold drop-down menu in the Source 2 menu group.
Live Bus Threshold: Adjust the threshold above which a phase is considered live from 50% to
100% of the nominal voltage (i.e., the PT rating, line-neutral for wyes, line-line for deltas) in steps
of 1% from the Live Bus Threshold drop-down menu in the Source 2menu group.
5.3.2.5 Configuration
Select the condition under which the “Dead Source” status output is true from the following
options in the Configuration drop-down menu:
• None – Dead source function is disabled
• LV1 and DV2 – Voltage source 1 live and voltage source 2 dead
• DV1 and LV2 – Voltage source 1 dead and voltage source 2 live
• DV1 or DV2 – Voltage source 1 dead or voltage source 2 dead
• DV1 xor DV2 – One voltage source is dead, the other is live
• DV1 and DV2 – Both sources are dead
NOTE:A source is considered dead when all voltage phases are below the dead bus threshold.
A source is considered live when all voltage phases are above the live bus threshold.
5
Synch Check relay81
Figure 5-12 Settings for Synch Check Relay
5
Single point functions82
5.3.3 Usage
When two voltage source circuit breakers are selected as the two sources for synch check relay,
if the differences in their magnitude, phase and frequency are within the set limits, the synch
check shows the synch status as Live and Synchronized. The Dead Source status is also shown
depending on whether the selected criterion for the dead source is met.
Figure 5-13 shows the status of a typical Synch Check Relay.
Figure 5-13 Synch Check status
5
Synch Check relay83
5.3.3.1 Event logging
The following events are logged for the Synch Check relay:
• Synch Check Control Enabled 1…6 – Synch check relay 1…6 has been enabled
• Synch Check Control Disabled 1…6 – Synch check relay 1…6 has been disabled
• Synch Check 1…6 Sources Not Synchronized – Messengers that are providing voltage
information for synch check relay are not synchronized, so Entellisys is unable to check for
synchronization between voltage sources.
• Synch Check 1…6 Sources Not Compatible – Voltage sources for synch check relay 1…6 are
5
not compatible; i.e. they have different PT configurations or ratings
• Synch Check 1…6 Dead Source Operate – Dead source criteria for synch check relay 1…6
have been met
• Synch Check 1…6 Dead Source Drop Out – Dead source criteria for synch check relay 1…6
have been met
• Synch Check 1…6 V1 Above Minimum – Voltage source 1 for synch check relay 1…6 is above
the live source threshold
• Synch Check 1…6 V1 Below Maximum – Voltage source 1 for synch check relay 1…6 is below
the dead source threshold
• Synch Check 1…6 V2 Above Minimum – Voltage source 2 for synch check relay 1…6 is above
the live source threshold
• Synch Check 1…6 V2 Below Maximum – Voltage source 2 for synch check relay 1…6 is below
the dead source threshold
To view these events, click Sequence of Events on the Main Menu.
Single point functions84
6Zones, buses, and topologies
6.0.1 Overview
6.0.1.1 Zones and buses
Entellisys implements Multi-Source Ground Fault (MSGF), Bus Differential (BD), and Zone
Selective Interlock (ZSI) as zone functions. In Entellisys, a zone is a set of circuit breakers
connected to a common bus. The circuit breakers in a zone may control the power to that bus
(e.g., a main circuit breaker), or the circuit breakers may be fed by that bus (e.g., a feeder or
sub-feeder).
The system is divided into zones to provide better performance and simplify the configuration.
MSGF, BD and ZSI will respond to faults that are within their zone and ignore faults outside the
zone. This allows the zones to be inherently selective with the other zones and individual circuit
breaker protection functions.
The system in Figure 6-1 contains two zones: Zone 1 is made up of Main 1 (M1), Tie 1 (T1), Feeder
Left 1 (FL1) and Feeder Left 2 (FL2). Zone 2 is made up of Main 2 (M2), Tie 1 (T1), Feeder Right 1
(FR1) and Feeder Right 2 (FR2). It also contains two buses, Bus 1 and Bus 2, separated by a tie
circuit breaker.
6
Figure 6-1 One-Line diagram for a main-tie-main system
The main-tie-main is a common configuration, but the concept of buses and zones is not limited
to a main-tie-main configuration. Entellisys only requires that the number of zones is between
one and four, and the number of circuit breakers per zone is between one and thirty (or zero if a
zone is not used).
85
6.0.1.2 Topologies
In Figure 6-1 the bus to which the member circuit breakers of a given zone are connected can
be powered in several different ways (this assumes that the main circuit breakers M1 and M2
are each connected to a source, e.g., a utility or generator). For example, Bus 1 can be powered
from the source at M1, it can be powered from the source at M2, or it can be powered by both
sources in parallel (it can also be unpowered). The same options are available for Bus 2. How the
buses are powered depends on the state of the mains and the tie.
Circuit breakers that control the flow of power to a bus, such as M1, M2, and T1 in the example
above, are referred to in Entellisys as topology circuit breakers. For example, if M1 is open, M2 is
closed, and T1 is closed, then M2 powers both Bus 1 and Bus 2. Entellisys allows up to eight
topology circuit breakers to be specified. The state of the topology circuit breakers defines how
a given bus is powered, and each state is referred to as a topology.
6
Entellisys allows the user to select different settings for the multi-point functions based on the
each zone's topology. For example, a user might want different pickup settings for the zone 1
bus differential function based on whether the bus is powered by the source at M2 versus the
source at M1.
6.0.2 Setup
6.0.2.1 Zones
For a system with B buses, Entellisys provides 2
topology can have its own settings associated with it for each multi-point function. (See Bus
Differential Relay on page 89, Multi-Source Ground-Fault Relay on page 93, and Zone Selective
Interlock on page 103 for more details). In the example above, there are two buses, so there are
four topologies, numbered 0 through 3. In this case, the user can select settings for topologies
1–3. Entellisys reserves topology 0 settings for the Reduced Let-Through Mode settings (see
Reduced Let-Thru Mode on page 111
The setup of the zones and topologies is done by GE before the switchgear is shipped to the
customer. It is not done by the customer.
Entellisys provides a maximum of four zones. The example above only has two zones, however,
so Zone 3 and Zone 4 do not contain any member circuit breakers. The zone definitions for the
example one-line in Figure 6-1 are shown below:
Zone 1 Member Circuit Breakers
M1
for more information).
B
Topologies numbered 0 to 2B – 1. Each
T1
FL1
FL2
Zone 2 Member Circuit Breakers
M2
T1
FR1
FR2
Zones, buses, and topologies86
6.0.2.2 Buses, topologies and the Association Matrix
In the system in Figure 6-1, circuit breakers M1, M2, and T1 are topology circuit breakers, since
their state (i.e., open or closed) determines how the buses are powered. In the system shown in
Figure 6-1, there are three different ways in which a bus can be powered, so there are three
topologies for each zone:
Zone 1
• Topology 1: Bus 1 powered by source at M1 (or not powered)
• Topology 2: Bus 1 powered by source at M2
• Topology 3: Bus 1 powered by sources at M1 and M2
Zone 2
• Topology 1: Bus 2 powered by source at M2 (or not powered)
• Topology 2: Bus 2 powered by source at M1
• Topology 3: Bus 2 powered by sources at M1 and M2
This topology definition is summarized in the Table 6-1 below. Entellisys refers to this table as
the Association Matrix.
Table 6-1 Association Matrix
T1M2M1Zone 1 TopologyZone 2 Topology
6
OpenOpenOpen11
OpenOpenClosed11
OpenClosedOpen11
OpenClosedClosed11
ClosedOpenOpen11
ClosedOpenClosed12
ClosedClosedOpen21
ClosedClosedClosed33
NOTE:Bus 1 in Zone 1 is always powered by the source connected to circuit breaker M1 (or is
unpowered), except for the following two cases:
Case 1: The circuit breaker M1 (Topology Circuit Breaker 1) is open and circuit breakers M2
(Topology Circuit Breaker 2) and T1 (Topology Circuit Breaker 3) are closed. In this case Bus 1 is
powered by the source connected to M2. For that row in the Association Matrix, the Topology for
Zone 1 is therefore 2.
Case 2: All three topology circuit breakers are closed, in which case Bus 1 is powered by the
sources connected to M1 and M2, in parallel. For that row in the Association Matrix, the
Topology for Zone 1 is therefore 3. For Zone 1, all other rows in the Association Matrix are set to
1. A similar analysis applies to Zone 2.
87
6.0.3 Usage
The purpose of configuring the zones, buses, and topologies is to define the system properties
for the multi-point functions (BD, MSGF, and ZSI), which, as noted above, operate on zones. This
information is also used by the PT Throwover function (see PT Throw-Over on page 99
details). Once this setup is completed (typically by GE before shipping) no further action is
required unless the switchgear line-up changes (e.g., a new circuit breaker is added).
To view a summary of the zone configuration, on the Maintenance screen click the Zone Configuration tab as show in Figure 6-2.
Figure 6-2 Zone Configuration summary
6
for
Zones, buses, and topologies88
7Multipoint functions
7.1 Bus Differential Relay
Entellisys offers optional Bus Differential Relay Protection. The bus differential relay monitors
the currents on each phase entering and leaving a zone (refer to section on zones and
topologies for more information). If a fault occurs within the zone, the bus differential relay will
detect this.
Because Bus Differential can discriminate between in zone and out of zone faults, the pickup
settings of the Bus Differential relay can be set independent of the settings needed to serve the
load. For example, if the 3,200A main Short Time pickup is set at 6X to start all loads than the
minimum in zone fault the main will detect is 19,200A. Bus Differential can be set to levels
similar to ground fault (1200A or less), offering far more sensitivity to detect bus and circuit
breaker faults.
Bus Differential Protection has two types of relays to select from: an alarm-only relay and a trip
relay. The trip relay also has an optional backup function. If the backup function is enabled, the
Bus Differential function will open additional circuit breakers in the event that opening the circuit
breakers that feed the zone does not clear the fault. This can happen, for example, when the
fault is in a tie circuit breaker that only has one set of CTs. The backup function can be
configured to operate with no additional delay, or after 100 msec of operation of the primary
relay.
7
The alarm-only relay activates an alarm if the fault is above the specified limit for the specified
duration of time. The trip relay opens/trips the trip and/or backup targets and also activates an
alarm if the fault is above the specified limit for the specified duration of time.
7.1.1 Setup
7.1.1.1 Configuring Bus Differential zones
The Bus Differential configuration, namely the member circuit breakers for each zone, the
current flow direction, and the circuit breakers to trip, is set up by GE.
7.1.1.2 User settings
Entellisys supports up to 16 topologies, from 0 to 15. Topology 0 is the Reduced Let-Thru Mode
topology and topology 1 is the default topology. If no topology circuit breakers are defined,
Entellisys supports only topologies 0 and 1. See Zones, buses, and topologies on page 85
more information.
Each Bus Differential Relay (Alarm-Only and Trip) can be enabled or disabled in each zone for
each topology. Bus Differential has two pickup settings and two time delay settings for each
relay (i.e., Alarm-Only and Trip) in each zone and for each topology. The backup function of the
Trip relay can be enabled to operate along with the Trip relay or after a delay of 100 msec by
selecting Trip Immediately or Trip After 100msec from the Backup Time Delta drop-down
menu on the Topology Settings tab as shown in Figure 7-3. These two settings are also
topology-specific.
for
Bus Differential Relay89
The only setting that is not topology specific on the Topology Settings tab is the Trip/Open
setting that determines whether the Trip relay just opens the circuit breakers (either trip-targets
or backup-trip-targets) or opens the circuit breaker and activates the lockout too.
7.1.1.3 Setting Bus Differential pickups/delays
To configure pickup and delay settings
1. On the Main Menu, click User Settings.
2. Click Advanced Protection, and then click Bus Differential as shown in Figure 7-3.
3. Select the zone number and topology number, and then select the appropriate settings for
pickup setting 1, pickup setting 2, etc.
Pickup setting 1 must always be less than pickup setting 2. A similar constraint is enforced for
time delay settings; time delay setting 1 must always be greater than time delay setting 2. A
second constraint for pickup settings is that the pickup setting (1 or 2) cannot be less than the
minimum pickup of its bus differential zone. A bus differential zone's minimum pickup is
7
computed as 20% of the CT rating of the largest circuit breaker of that zone. So, although the
allowed pickup setting range for the Bus Differential Relay is 30 to 22,000 Amps, the actual
allowed range is only from “zone-minimum-pickup” to 22,000 Amps.
There are seven delay bands available:
For 60 Hz systems
Band 1: 0.025 sec < T < 0.092 sec (Note: The actual fault clearing time depends on the energy
content of the current at the circuit breaker.)
Band 2: 0.058 sec < T < 0.158 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.167 sec < T < 0.267 sec
Band 5: 0.217 sec < T < 0.317 sec
Band 6: 0.283 sec < T < 0.383 sec
Band 7: 0.400 sec < T < 0.500 sec
For 50 Hz systems
Band 1: 0.030 sec < T < 0.095 sec (Note: The actual fault clearing time depends on the energy
content of the current at the circuit breaker.)
Band 2: 0.060 sec < T < 0.160 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.170 sec < T < 0.270 sec
Band 5: 0.220 sec < T < 0.320 sec
Band 6: 0.280 sec < T < 0.380 sec
Band 7: 0.400 sec < T < 0.500 sec
The pickup default is 1200 Amps and the time delay default is BAND 3.
If Topology Settings is set to Topology 1 and Apply to all Topologies is selected, then the
settings of topology 1 are applied to all topologies from 1 to 2
settings to different topologies, click Advanced Settings and select the desired topology and
settings as shown in Figure 7-3. For topology 0, settings are selected separately and these
settings are used when the Reduced Let-Thru Mode is enabled.
Multipoint functions90
(num of buses)
– 1. To apply different
7.1.1.4 Setting up Bus Differential alarms
To activate an alarm (alarm-only and/or trip) when the Bus Differential Relay of a zone
operates
1. On the Main Menu, click User Settings, and then select Alarms.
2. On the Alarms screen, click Alarms Setup as shown in Figure 7-4. (See Alarms and events
on page 187 for a detailed list of the different alarms supported by the Bus Differential
Relay.)
To help distinguish among the alarms of different bus differential zones when the alarms are
actually activated enter a comment in the Comment text box.
Figure 7-3 Bus differential user settings
7
Bus Differential Relay91
Figure 7-4 Bus differential alarms setup
7
7.1.2 Troubleshooting
Bus Differential Setting Change Rejected events are observed in the Sequence of Events log
• Verify that the pickup setting is within the valid range. Valid range is from “Zone Minimum
Pickup” to 22,000 Amps. (See Setting Bus Differential pickups/delays on page 90
Frequent suspended/resumed events are seen
• Verify that both CPUs are operating with the hardware clock. This can be done from the
System Health screen. The Synchronization hardware OK indicator lights should be green for
both CPUs.
7.1.3 Events generated by the Bus Differential Relay
To view a table of the events generated by the Bus Differential Relay, see Alarms and events
on page 187.
7.1.4 Alarms generated by the Bus Differential Relay
To view a table of the alarms generated by the Bus Differential Relay, see Alarms and events
on page 187.
.)
Multipoint functions92
7.2 Multi-Source Ground-Fault Relay
Entellisys offers optional Multi-Source Ground-Fault Relay Protection. Multi-source Ground Fault
is needed in systems where there is a parallel path for the neutral current, for example, in a
double-ended substation with two mains and a tie circuit breaker. In that case, the neutral
current from either side can return through both the neutral bus at the tie and the ground bus.
Therefore, a ground fault algorithm cannot just look at the currents in one main circuit breaker
or just the tie circuit breaker. MSGF is implemented on a per-zone basis (see Zones, buses, and
topologies on page 85 for more information on this topic). The zone functions measure the total
ground fault current into the zone, not the ground fault current from the source. The zone
function trips all circuit breakers that feed that zone.
MSGF also has a summation function that measures the total ground current from all sources.
The summation function and the zone functions interact. If a zone function is in pickup, the
summation function is suspended until the zone drops out of pickup. If no zone is in pickup, the
summation function trips the ties when it times out. The summation function can also be set to
open the mains. This allows the zone to clear the fault without unnecessarily tripping tie circuit
breakers in systems with three or four main circuit breakers.
Multi-Source Ground-Fault Relay has two types of relays to select from: an alarm-only relay and
a trip relay. The trip relay has a built-in backup function. MSGF also includes an optional backup
function. If the backup function is enabled, the MSGF function will open additional circuit
breakers in the event that opening the circuit breakers that feed the zone does not clear the
fault. This can happen, for example, when the fault is in a tie circuit breaker that only has one
set of CTs. The backup function can be configured to operate with no additional delay, or after
100 msec of operation of the primary relay.
7
Each relay comes with a set of pickup and delay settings. Each relay can have either a constant
time or an inverse time. The alarm-only relay activates an alarm if the fault is above the
specified limit for the specified duration of time. The trip relay opens/trips the trip and/or
backup targets and also activates an alarm if the fault is above the specified limit for the
specified duration of time.
7.2.0.1 Interoperation with Zone Selective Interlock function
Each MSGF zone can be configured as a member of a ZSI Ground Fault zone. See Zone Selective
Interlock on page 103 for more information.
Multi-Source Ground-Fault Relay93
7.2.1 Setup
7.2.1.1 User settings
Each Multi-Source Ground-Fault relay (Alarm-Only and Trip) can be enabled or disabled in each
zone for each topology (see Figure 7-5). Multi-Source Ground-Fault has one pickup setting, one
time delay setting and one Curve I
zone and for each topology. The backup function of the Trip relay (zones 1-4) can be enabled to
operate along with the Trip relay or after a delay of 100 msec by selecting Trip Immediately or
Trip After 100msec from the Backup Time Delta drop-down menu on the Topology Settings tab
as shown in Figure 7-3. These two settings are also topology-specific.
The only setting that is not topology specific on the Topology Settings tab is the Trip/Open
setting that determines whether the Trip relay just opens the circuit breakers (either trip-targets
or backup-trip-targets) or opens and activates the lockout too.
7
Figure 7-5 Multi-Source GF user settings
2
T setting for each relay (i.e., Alarm-Only and Trip) in each
2. Click Advanced Protection, and then click Multi Source GF.
3. Select the zone number and topology number, and then select the appropriate settings for
2
pickup settings, time delay and Curve I
T, etc.
The pickup setting cannot be less than the minimum pickup for that MSGF zone. An MSGF zone's
minimum pickup is computed as 20% of the frame size of the largest circuit breaker of that
zone. So, although the allowed pickup setting range for the MSGF Relay is 30 to 1200 Amps, the
actual allowed range is only from “zone-minimum-pickup” to 1200 Amps.
There are seven delay bands available:
For 60 Hz systems
Band 1: 0.025 sec < T < 0.092 sec (Note: The actual fault clearing time depends on the energy
content of the current at the circuit breaker.)
Band 2: 0.058 sec < T < 0.158 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.167 sec < T < 0.267 sec
Band 5: 0.217 sec < T < 0.317 sec
Band 6: 0.283 sec < T < 0.383 sec
Band 7: 0.400 sec < T < 0.500 sec
For 50 Hz systems
Band 1: 0.030 sec < T < 0.095 sec (Note: The actual fault clearing time depends on the energy
content of the current at the circuit breaker.)
7
Band 2: 0.060 sec < T < 0.160 sec
Band 3: 0.100 sec < T < 0.200 sec
Band 4: 0.170 sec < T < 0.270 sec
Band 5: 0.220 sec < T < 0.320 sec
Band 6: 0.280 sec < T < 0.380 sec
Band 7: 0.400 sec < T < 0.500 sec
The pickup default is 1200 Amps and the time delay default is BAND 3 and the Curve I2T default
is “disabled.”
If Topology Settings is set to Topology 1 and Apply to all Topologies is selected, then the
settings of topology 1 are applied to all topologies from 1 to 2
(num of buses)
– 1. To apply different
settings to different topologies, click Advanced Settings and select the desired topology and
settings as shown in Figure 7-6. For topology 0, settings are selected separately and these
settings are used when the Reduced Let-Thru Mode is enabled.
Multi-Source Ground-Fault Relay95
Figure 7-6 Multi-Source GF user settings for different topologies
7
Multipoint functions96
7.2.1.3 Setup of Multi-Source Ground-Fault alarms
To activate an alarm (alarm-only and/or trip) when the Multi-Source Ground-Fault Relay of
a zone operates
1. On the Main Menu, click User Settings, and then select Alarms.
2. On the Alarms screen, click Alarms Setup as shown in Figure 7-7. (See Alarms and events
on page 187 for a detailed list of the different alarms supported by the Multi-Source
Ground-Fault Relay.)
To help distinguish among the alarms of different MSGF zones when the alarms are actually
activated enter a comment in the Comment text box.
Figure 7-7 Setting up Multi-Source GF alarms
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Multi-Source Ground-Fault Relay97
7.2.2 Troubleshooting
Multi-Source Ground Fault Setting Change Rejected events are observed in the Sequence of
Events log
• Verify that the pickup setting is within the valid range. Valid range is from “Zone Minimum
Pickup” to 1200 Amps. (See Setting Multi-Source Ground-Fault pickup/delay on page 95
Backup relay is not working
• Verify that the backup function is enabled for the concerned zone in the concerned
topology.
Frequent suspended/resumed events are seen
• Verify that both CPUs are operating with the hardware clock. This can be done from the
System Health screen. The Synchronization hardware OK indicator lights should be green for
both CPUs.
.)
7
7.2.3 Events generated by Multi-Source Ground-Fault Relay
To view a table of events generated by the Multi-Source Ground-Fault Relay, see Alarms and
events on page 187.
7.2.4 Alarms generated by Multi-Source Ground-Fault Relay
To view a table of alarms generated by the Multi-Source Ground-Fault Relay, see Alarms and
events on page 187.
Multipoint functions98
7.3 PT Throw-Over
The PT Throw-Over changes the voltage source for the metering and relay functions for a circuit
breaker, based on how a bus is powered. It is recommended that you review the chapter on
Zones and Topologies (see Zones, buses, and topologies on page 85
many of the terms and concepts used here are defined more thoroughly in that chapter.
Consider the main-tie-main system shown in Figure 7-8. Typically there is a power source, such
as a utility source or generator, connected to each main (circuit breakers M1 and M2) and a set
of potential transformers (PTs) at each main that step down the primary voltage so that it can
be measured by the EntelliGuard Messenger at the circuit breaker.
Figure 7-8 One-line diagram for a main-tie-main
) before continuing, since
7
One of the advantages of Entellisys is that voltage information measured at one circuit breaker
can be used for metering and relaying functions at another circuit breaker. In the system shown
in Figure 7-8, what voltage information should be used for the feeder circuit breakers (FL1, FL2,
FR1, and FR2)?
The answer, of course, depends on the state of the topology circuit breakers M1, M2, and T1 (see
Zones, buses, and topologies on page 85
circuit breaker M1 is powering Bus 1 (i.e., M1 is closed, T1 is open) then the metering and
relaying functions at FL1 and FL2 should use the voltage data from M1. If M2 is powering Bus 1,
then the metering and relaying functions at FL1 and FL2 should use the voltage data from M2.
NOTE:Although the main-tie-main is a common configuration, this feature is not limited to
that configuration.
for more information). For example, if the source at
PT Throw-Over99
7.3.1 Setup
The setup of the PT sources is done by GE before the switchgear is shipped to the customer,
rather than by the customer.
Before showing how the PT sources are defined for this case, review the definition of each zone
and the meaning of the topologies for each zone.
Zone 1 Member Circuit Breakers
• M1
• T1
• FL1
• FL2
7
Zone 1 Topologies
• Topology 1: Bus 1 powered by source at M1 (or not powered)
• Topology 2: Bus 1 powered by source at M2
• Topology 3: Bus 1 powered by sources at M1 and M2 in parallel
Zone 2 Member Circuit Breakers
• M2
• T1
• FR1
• FR2
Zone 2 Topologies
• Topology 1: Bus 2 powered by source at M2 (or not powered)
• Topology 2: Bus 2 powered by source at M1
• Topology 3: Bus 2 powered by sources at M1 and M2 in parallel
The completed PT source table for this example is shown in Table 7-1. Topology 0 is the Reduced
Let-Through topology (see Reduced Let-Thru Mode on page 111
typically has the same configuration as Topology 1.
Note in Table 7-1 that M1 and M2 always use their own voltage information, regardless of
topology. The reason is that, in the example, these two circuit breakers have PTs attached and
therefore do not need to use voltage information from another circuit breaker.
for more information). It
For the circuit breakers in Zone 1, Topology 1 indicates that the bus (Bus 1) is powered by the
source at circuit breaker M1. Therefore, FL1 and FL2 use M1 as the voltage source. For the circuit
breakers in Zone 2, Topology 1 indicates that the bus (Bus 2) is powered by the source at circuit
breaker M2. Therefore, FR1 and FR2 use M2 as the voltage source.
For the circuit breakers in Zone 2, Topology 1 indicates that the bus is powered by the source at
circuit breaker M2. For the circuit breakers in Zone 2, Topology 2 indicates that the bus is
powered by the source at circuit breaker M1. The Topology 2 settings are filled in to reflect this.
Multipoint functions100
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