Eaton Cutler-Hammer Digitrip 1150 User manual

Effective 8/18/99
Page 1I.L. 70C1036H01 I.L. 70C1036H01
Table of Contents
1.0 General Description of Digitrip Units....................... 5
1.1 Protection ............................................................... 5
1.2 Mode of Trip and Status Information....................... 5
1.3.1 Installation of the Trip Unit............................ 5
1.3.2 Rating Plug Installation................................. 6
1.3.3 Trip Unit/Rating Plug Removal ..................... 7
1.4 Wiring ..................................................................... 7
1.6 DT 1150 Power/Relay Module ................................ 7
1.6.1 Auxiliary Power ............................................ 7
1.6.2 Alarm Contacts ............................................ 7
1.7 Standards ............................................................... 8
2.0 Generall Description of
Magnum Circuit Breakers ....................................... 8
2.1 General .................................................................. 8
2.2 Low-Energy Trip Actuator ....................................... 9
2.3 Ground Fault Protection ......................................... 9
2.3.1 General ........................................................ 9
2.3.2 Residual Sensing ....................................... 10
2.3.3 Source Ground Sensing............................. 10
2.3.4 Zero Sequence Sensing............................. 10
2.3.5 Multiple Source/Multiple Ground ................ 10
2.3.6 Ground Fault Settings ................................ 10
2.4 Current Sensors (Magnum Frames less than or
equal to 3200A) .................................................... 11
2.5 Current Sensors (Magnum Frames greater
than 3200A).......................................................... 11
3.0 Principles of Operation ......................................... 11
3.1 General ................................................................ 11
3.2 Trip and Operation Indicators ............................... 11
3.2.1 Status LED................................................. 12
3.2.2 Alarm LED ................................................. 12
3.2.3 Trip LED..................................................... 12
3.3 Making Current Release....................................... 12
3.4 Zone Interlocking .................................................. 12
3.5 PT Module ............................................................ 17
4.0 Programming/View Digitrip 1150........................... 17
4.1 Main Menu............................................................ 17
4.1.0 Power Up Sequence .................................. 17
4.1.1 PushbuttonDefinition ................................. 17
4.1.2 Blink mode ................................................. 20
4.1.3 Programming/ViewingScreens .................. 20
4.1.4 Reset Pushbutton Operation (after trip)...... 20
4.2 Program Settings PGM SET................................. 21
4.2.1 Curve Type Selection and Pickup/
Time Settings ....................................................... 21
4.2.2 AMP UNBALANCE, PHASE LOSS ............ 24
4.2.3 INCOM....................................................... 24
4.2.4 Aux RELAYS.............................................. 25
4.2.5 ALARMS .................................................... 26
4.2.6 ACCessory BUS (Relays) .......................... 26
4.2.7 TRIPLINK................................................... 26
4.2.8 Setting TIME .............................................. 27
4.2.9 SelectingDISPLAYS .................................. 27
4.2.10GENERAL settings .................................... 27
4.3 View Settings (VIEW SET) ................................... 27
4.3.1 Firmware Menu .......................................... 27
4.4 METER................................................................. 27
4.5 HARMONIC Menu................................................ 28
4.6 EventLOG............................................................. 28
4.7 Power and Energy Parameters............................. 28
4.8 Power Quality ....................................................... 29
4.8.1 Power Factor, THD and Crest Factor ......... 29
4.8.2 Alarms........................................................ 29
4.9 WAVEFORM CAPTURE feature .......................... 29
4.9.1 Six Cycle Waveform Capture on trip .......... 29
4.9.2 One Cycle Waveform Capture on alarms... 29
5.0 Test Procedure ..................................................... 29
5.1 General ................................................................ 29
5.2 When to Test ........................................................ 30
5.3.1 Self Testing ................................................ 30
5.3.2 Functional Field Testing ............................. 30
5.4 Performance Testing for Ground Fault Trip Units . 30
5.4.1 Code Requirements ................................... 30
5.4.2 Standard Requirements ............................. 30
5.4.3 General Test Instructions ........................... 30
6.0 Battery .................................................................. 31
6.1 General ................................................................ 31
6.2 Battery Check....................................................... 31
6.3 Battery Installation and Removal .......................... 32
7.0 Frame Ratings
(Sensor Ratings and Rating Plugs)....................... 32
8.0 Record Keeping.................................................... 33
9.0 References ........................................................... 33
9.1 Magnum and Magnum DS Circuit Breakers ......... 33
9.2 Time-Current Curves ............................................ 33
Appendix A Zone Interlocking Example........................ 38
Appendix B Troubleshooting Guide .............................. 39
Appendix C Typical Breaker Master
Connection Diagram............................................. 41
Appendix D Display Menu Diagrams ...................... 42- 63
Appendix E Display Abbreviations.......................... 65- 66
Appendix F Auxiliary Relays......................................... 67
Appendix G Accessory Bus Digital
Output Modules .................................................... 68
Instructions for Digitrip Models 1150 and 1150i
Trip Units for use only in Cutler-Hammer Magnum
and Magnum DS Circuit Breakers
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Effective 8/18/99
Page 2 I.L. 70C1036H01
WARNING
DO NOT ATTEMPT TO INSTALL OR PERFORM
MAINTENANCE ON EQUIPMENT WHILE IT IS
ENERGIZED. DEATH OR SEVERE PERSONAL INJURY
CAN RESULT FROM CONTACT WITH ENERGIZED
EQUIPMENT. ALWAYS VERIFY THAT NO VOLTAGE IS
PRESENT BEFORE PROCEEDING. ALWAYS FOLLOW
SAFETY PROCEDURES. CUTLER-HAMMER IS NOT
LIABLE FOR THE MISAPPLICATION OR
MISINSTALLATION OF ITS PRODUCTS.
WARNING
OBSERVE ALL RECOMMENDATIONS, NOTES,
CAUTIONS, AND WARNINGS RELATING TO THE
SAFETY OF PERSONNEL AND EQUIPMENT. OB-
SERVE AND COMPLY WITH ALL GENERAL AND
LOCAL HEALTH AND SAFETY LAWS, CODES, AND
PROCEDURES.
NOTE: The recommendations and information contained
herein are based on experience and judgement, but
should not be considered to be all inclusive or to cover
every application or circumstance which may arise.
Figure 1.1 Digitrip 1150 Catalog # 11LSIG Trip Unit with Rating Plug
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Effective 8/18/99
Page 3I.L. 70C1036H01
Table 1.1a Protection Functions for Digitrip 1150/1150i Trip Units
Notes: 1. ANSI/UL versions are limited to 1200 Amperes to comply with UL and NEC standards.
2. Four cause of trip LEDs indicate LONG, SHORT, INST or GROUND trip. Making Current Release is
indicated by the Instantaneous LED.
3. An additional setting is marked M1 where:
800 - 3200A Frame M1 = 14 x In for Plug Amps 200 through 1250A
M1 = 12 x In for Plug Amps 1600, 2000, 2500A
M1 = 10 x In for Plug Amps 3000, 3200A
4000 - 6300A Frame M1 = 14 x In for Plug Amps 2000, 2500A
M1 = 12 x In for Plug Amps 3200, 4000, 5000A (see Section 2.5)
M1 = 10 x In for Plug Amps 6300A
4. Only available when Long Time I2T is selected.
5. Phase protection with 3 response types.
Trip Unit Type Digitrip 1150 Digitrip 1150i
Ampere Range 200A-5000A 200A-6300A
RMS Sensing Yes Yes
Protection and Coordination
Protection Ordering Options Catalog #
Fixed Rating Plug (In)
OverTEMPerature TRIP
Curve Type
SLOPE
11LSI/11LSIG, 11LSIA
Yes
Yes
LSI/LSIG, LSIA
I2T, I4T
IEEE5
11IEC/11IEC-EF
Yes
Yes
LSI/LSIG
I2T, I4T
IEC5
Long LONG delay Pick Up
Delay LONG delay TIME @ 6 x (Ir) I2T
Protection LONG delay TIME @ 6 x (Ir) I4T
LONG delay thermal MEMORY
0.4-1.0 x (In)
2-24 seconds
1-5 seconds
Yes
0.4-1.0 x (In)
2-24 seconds
1-5 seconds
Yes
Short SHORT delay Pick Up3
Delay SHORT delay TIME @ 8 x (Ir) I2T4
Protection SHORT delay TIME FLAT
SHORT delay TIME ZONE INTERLOCK
150-1000% x (Ir)
0.10-0.50 s
0.10-0.50 s
Yes
150-1000% x (Ir)
0.10-0.50 s
0.10-0.50 s
Yes
Instan- INSTantaneous Pick Up3
taneous Off Setting
Protection Making Current Release
200-1000% x (In)
Yes
Yes
200-1000% x (In)
Yes
Yes
Neutral 4th Pole or External Neutral Trip
Protection Yes-11LSI only (0.50, 1.00) Yes-11IEC only (0.50, 1.00)
Ground GROUND fault option
(Earth) GROUND fault Pick Up
Fault Off Position
Protection GROUND fault delay @ .625 x (In) I2T
GROUND fault delay FLAT
GROUND fault ZONE INTERLOCK
GROUND faultmemory
Yes
25-100% x (In)1
No
100-500 ms
100-500 ms
Yes
Yes
Yes
10-100% x (In)
Yes
100-500 ms
100-500 ms
Yes
Yes
Phase Protection
AMP UNBALANCE
PHASE LOSS (current-based) Yes Yes Yes Yes
System Diagnostics / Protection Related Alarms
Status/Long Pick Up LED
Cause of Trip LED’s Yes Yes2Yes Yes2
HighLOAD ALARM
Long Delay Pick Up ALARM
GROUND ALARM
GROUND ALARM only - style
NEUTral AMPere ALARM
OPeration COUNT ALARM
Yes
Yes
Yes-11LSIG
11LSIA
Yes
Yes
Yes
Yes
Yes-11IEC-EF
–
Yes
Yes
Auxiliary Relay Contacts (Programmable)
Block Close (1 contact)
ALARM/TRIP (2 contacts) Yes Yes Yes Yes
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Page 4 I.L. 70C1036H01
Current Metering Units Tolerance Notes
IA, IB, IC, IN, IG
IA, IB, IC (AVG)
IN, IG (AVG)
IA, IB, IC (Max)
IN, IG (Max)
IA, IB, IC (Min)
IN, IG (Min)
Amperes
Amperes
Amperes
Amperes
Amperes
Amperes
Amperes
±1% FS Real time data, FS = In rating
5 MINUTE AVERAGE
5 MINUTE AVERAGE
Group values held until Reset.
Based on approximately 1 second
time interval
Voltage Metering
VAB, VBC, VCA Volts ±1% FS FS (Full Scale) = 690 V
Power Metering
Power
kVA
kvar
DEMAND kW
DEMAND Max kW
DEMAND kVA
DEMAND Max kVA
kW
kVA
kvar
kW
kW
kVA
kVA
±2%FS
±2%FS
±2%FS
±2%FS
±2%FS
±2%FS
±2%FS
Approximately 1 second update
LAST AVG - 5 MIN INTERVAL
SLIDING or FIXED 15 MIN INTERVAL*
LAST AVG - 5 MIN INTERVAL
SLIDING or FIXED 15 MIN INTERVAL*
Energy Metering
ENERGY kWh
ENERGY Rev kWh
kVAh
kWh
kWh
kVAh
Metering Related Alarms
kVA DEMAND ALARM
kW DEMAND ALARM 1 to 12500 1 to 12500 LAST AVG - 5 min fixed interval LAST AVG - 5 min fixed interval
Other
kVAh PULSE INITIATE
kWh PULSE INITIATE kVAh kWh See section
4.7 INITIATE is an abbreviation forINITIATOR
INITIATE is an abbreviation forINITIATOR
* Only one of DEMAND Max kW or DEMAND Max kVA can be SLIDING INTERVAL
Table 1.1b Metering Data for Digitrip 1150/1150i Trip Units
Harmonic Units Notes
THD (Total Harmonic Distortion)
THDA
THDB
THDC
THDN
Per Harmonic Data
HARMON A
HARMON B
HARMON C
HARMON N
CF (Crest Factor)
CFA
CFB
CFC
CFN
0 to 99 percent
0 to 99 percent
0 to 99 percent
0 to 99 percent
0 to 99 percent
0 to 99 percent
0 to 99 percent
0 to 99 percent
1.0 to 25.5
1.0 to 25.5
1.0 to 25.5
1.0 to 25.5
phase A current
phase B current
phase C current
Neutral current
Fundamental through 27th
phase A current
phase B current
phase C current
phase N current
phase A current
phase B current
phase C current
phase N current
Power Factor /Frequency
PF (Power Factor)
PF MIN
PF MAX
0 to 1.00
0 to 1.00
0 to 1.00
Located in METER menu, realtime data
Value held until Reset
Value held until Reset
Hz (Frequency) Hz Located in METER menu
Power Quality Related Alarms (Programmable)
LOW PF ALARM
THD ALARM 50 to 95 percent 10 to 30 percent OFF setting available OFF setting available
Table 1.1c Power Quality Data for Digitrip 1150/1150i Trip Units
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Page 5I.L. 70C1036H01
If you have any questions or need further information or
instructions, please contact your local representative or
the Customer Support Center at 1-800-356-1234.
1.0 GENERAL DESCRIPTION OF DIGITRIP TRIP UNITS
The Digitrip Trip Units are breaker subsystems that
provide the protective functions of a circuit breaker. The
trip units are in removable housings, installed in the
breaker, and can be replaced or upgraded in the field by
the end user.
This instruction book specifically covers the application of
Digitrip Trip Units, as illustrated in Figure 1.1, installed in
Magnum and Magnum DS Breakers. Throughout this
Instructional Leaflet, the use of the term “Magnum
Breakers” refers to both the Magnum and Magnum DS
low-voltage, AC power circuit breakers.
The Magnum Digitrip line of trip units consists of the 1150
for UL standards, and model 1150ifor IEC standards.
Throughout this Instructional Leaflet, the use of the term
Digitrip 1150 trip units refers to both models unless
otherwise stated. There are three possible styles under
the DT 1150 (11LSI, 11LSIG, 11LSIA) and two styles
under the DT 1150i (11IEC and 11IEC-EF).
The Digitrip 1150 trip units may be applied on both 50 and
60 Hz systems.
Digitrip DT1150 family of trip units have two microproces-
sors in their design. The partitioning is such that one
processor is devoted totally to the task of current protec-
tion functions. This processor provides true RMS current
sensing for the proper coordination with the thermal
characteristics of conductors and equipment. The Digitrip
analyzes the secondary current signals from the circuit
breaker current sensors and, when preset current levels
and time delay settings are exceeded, will send an
initiating trip signal to the Trip Actuator of the circuit
breaker. The current sensors provide operating power to
the trip unit. As current begins to flow through the breaker,
the sensors generate a secondary current which powers
the trip unit.
The second microprocessor provides the display, commu-
nications, metering, harmonic calculations, alarming and
auxiliary relay functions. These additional features require
that auxiliary power be provided to the circuit breaker.
1.1 Protection
Each Digitrip DT1150 Trip Unit is completely self-con-
tained and requires no external control power to operate
its basic current protection functions. It operates from
current signal levels derived through current sensors
mounted in the circuit breaker. The types of protection
available for each model are shown in Table 1.1.
The Digitrip 1150 family of trip units provides five phase
and two ground (time-current) curve-shaping adjust-
ments. To satisfy the protection needs of any specific
installation, the exact selection of the available protection
function is adjustable. The short delay and ground fault
pick-up adjustments can be set for either FLAT or I2t
response. A pictorial representation of the applicable
time-current curves for the selected protection functions is
provided, for user reference, on the face of the trip unit as
shown in Figure 1.1.
NOTE: The Digitrip 1150 (11LSI style) and Digitrip 1150 i
(11IEC) are the two styles that can be used on 3-pole or
4-pole circuit breakers for the protection of the neutral
circuit. Only these two styles can provide neutral protec-
tion, although all styles can provide neutral metering and
alarming (see Figures 3.7, 3.8, and 3.9). Refer to the
National Electric Code (NEC) for the appropriate applica-
tion for 4-pole breakers.
1.2 Mode of Trip and Status Information
On all DT1150 units, a green light emitting diode (LED),
labeled Status, blinks approximately once each second to
indicate that the trip unit is operating normally. This Status
LED will blink at a faster rate if the Digitrip is in a pick-up,
or overload, mode.
Red LEDs on the face of the 1150 family of trip units flash
to indicate the cause, or trip mode, for an automatic trip
operation (for example, ground fault, overload, or short
circuit trip). A battery in the Digitrip unit maintains the trip
indication until the Reset button is pushed. The battery is
satisfactory if its LED lights green when the Battery Check
button is pushed (see Section 6).
NOTE: The Digitrip 1150 family provides all protection
functions regardless of the status of the battery. The
battery is only needed to maintain the automatic trip
indication.
1.3 Installation and Removal
1.3.1 Installation of the Trip Unit
Align the Digitrip unit with the molded guide ears on the
platform and spring clips of the Magnum Circuit Breaker.
Before plugging into the black edge connector, allign the
long pins on the bottom of the Digitrip into the white, I1,
connector. See Figure 1.2. .Press the unit into breaker
until the PC board edge engages into the connector and
the spring clips engage over the Digitrip’s housing.
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1.3.2 Rating Plug Installation
WARNING
DO NOT ENERGIZE THE MAGNUM BREAKER WITH
THE DIGITRIP REMOVED OR DISCONNECTED FROM
ITS CONNECTOR. DAMAGE TO INTERNAL CURRENT
TRANSFORMERS MAY OCCUR DUE TO AN OPEN
CIRCUIT CONDITION.
Figure 1.2 Installation of the Digitrip Unit into a Magnum Breaker (Side View)
CAUTION
IF A RATING PLUG IS NOT INSTALLED IN THE TRIP
UNIT, THE UNIT WILL INITIATE A TRIP WHEN IT IS
ENERGIZED.
Insert the rating plug into the cavity on the right-hand
side of the trip unit. Align the three pins on the plug with
the sockets in the cavity. The plug should fit with a slight
insertion force.
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To remove the trip unit from the circuit breaker, deflect the
top and bottom spring clips to release the unit from the
steel mounting plate. Pull the unit to disengage the trip
unit’s printed circuit board connectors J0 & I1 from the
circuit breaker (see Figure 1.2 and Appendix C).
1.4 Wiring
The internal components of the breaker and their connec-
tion points to the secondary contacts, are shown in the
breaker master connection diagram provided as Appendix
C.
1.5 Plexiglass Cover
A clear, tamper-proof plexiglass door sits on the breaker
cover. This door, if sealed, allows the settings to be
viewed but not changed, except by authorized personnel.
The plexiglass cover meets applicable tamper-proof
requirements. The cover is held in place by two cover
screws. Security is insured by the insertion of a standard
meter seal through the holes in both of the cover retention
screws. The plexiglass cover has an access cutout for the
View Functions group of pushbuttons and the Battery Test
pushbutton.
1.6 DT 1150 Power/Relay Module
The Power/Relay Module (see Figure 1.4) is a standard
accessory for the Digitrip 1150 model. The module is
installed on the molded platform under the trip unit in the
Magnum Circuit Breaker. The module covers the following
input voltage ratings: 120 VAC, 230 VAC, and 24/48 VDC.
The burden of the Power/Relay Module is 10VA.
1.6.1 Auxiliary Power
When the module is wired and supplied with proper
voltage, it will provide an auxiliary power supply so that
the DT 1150’s (LED) display will be functional even when
the circuit breaker has no load. A Digitrip 1150 unit
without auxiliary power will not display any data.
1.6.2 Alarm Contacts
A second function of this module is to provide either a trip
or alarm output contact via the two customer pro-
grammed relays within the module. An assortment of
relay functions can be assigned to these relays. See the
Aux Relay programming in Appendix D-15 and Appendix
F. Each relay is a normally open contact with a program-
ming identification of RELAY A and RELAY C. On the
breaker schematic these are labeled ATR_Alarm and
ATR_latch. The ATR_latch is a latching relay that will hold
contact status even if Auxiliary
Figure 1.3 Installation of the Rating Plug and Mounting
Screw
CAUTION
DO NOT FORCE THE RATING PLUG INTO THE
CAVITY.
Use a 1/8" (3 mm) wide screwdriver to tighten the M4
screw and secure the plug and the trip unit to the circuit
breaker (see Figure 1.3). Close the rating plug door.
CAUTION
THE M4 SCREW SHOULD BE TIGHTENED ONLY
UNTIL IT IS SNUG. DO NOT USE A LARGE SCREW-
DRIVER. A 1/8" (3 mm) WIDE SCREWDRIVER BLADE
IS ADEQUATE.
1.3.3 Trip Unit/Rating Plug Removal
To remove the rating plug from the trip unit, open the
rating plug door. Use a 1/8" (3 mm) wide screwdriver to
loosen the M4 screw. Pull the door to aid in releasing the
rating plug from the unit.
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Figure 1.4 Power/Relay 1150 Trip Unit
power is lost to the breaker. It does require Auxiliary
Power for resetting. The resetting of these relays requires
depressing the RESET pushbutton on the front panel of
the Digitrip 1150.
1.6.2.2 Ground Alarm
A ground fault alarm is one of nine programmable alarms
possible and can provide an early warning of a ground
fault condition in process via alarm LED.
In additional, an alarm relay can be programmed to be
energized. The alarm relay will reset automatically if the
ground current is less than the ground alarm pickup
setting.
On the LSIA style unit, a red ALARM ONLY LED (see
Figure 3.3) will indicate the presence of ground fault
current, when is in excess of GROUND PICKUP setting.
Ground tripping will not occur with the LSIA style unit.
1.6.2.3 Block Close Relay
Also in this module is a relay that can block the remote
closing of a circuit breaker after a trip condition. This
Block function is enabled by programming the Aux Relay
B. See Appendix D-15.
1.7 Standards
The Digitrip 1150 Trip Units are listed by the Underwriters
Laboratories, Inc.®, UL File E52096, for use in Magnum
Circuit Breakers. These same units are also listed by the
Canadian Standards Association (CSA) under file LR
43556.
All Digitrip units have also passed the IEC 947-2 test
program which includes radiated and conducted emission
testing. As a result, all units carry the CE mark.
2.0 GENERAL DESCRIPTION OF MAGNUM CIRCUIT BREAKERS
2.1 General
Magnum Circuit Breakers are tripped automatically on
overload or fault current conditions by the combined
action of three components:
1. The Sensors, which measure the current level
2. The Digitrip Trip Unit, which provides a tripping signal
to the Trip Actuator when current and time delay
settings are exceeded
3. The low-energy Trip Actuator, which actually trips the
circuit breaker
Figure 2.1 shows this tripping circuit for a typical Magnum
Breaker. This arrangement provides a very flexible
system, covering a wide range of tripping characteristics
described by the time-current curves referenced in
Section 9.2.
The automatic overload and short circuit tripping charac-
teristics for a specific circuit breaker are determined by
the ratings of the installed current sensors with a match-
ing rating plug and the selected functional protection
settings. Specific setting instructions are provided in
Section 4.
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When the functional protection settings are exceeded, the
Digitrip unit supplies a trip signal to the Trip Actuator. As a
result, all tripping operations initiated by the protection
functions of the Digitrip Trip Unit are performed by its
internal circuitry. There is no mechanical or direct mag-
netic action between the primary current and the me-
chanical tripping parts of the breaker, thus external
control power is not required for overload or fault current
tripping.
WARNING
IMPROPER POLARITY CONNECTIONS ON THE TRIP
ACTUATOR COIL WILL DEFEAT THE OVERLOAD
AND SHORT CIRCUIT PROTECTION, WHICH COULD
RESULT IN PERSONAL INJURY.
OBSERVE POLARITY MARKINGS ON THE TRIP
ACTUATOR LEADS AND CONNECT THEM PROPERLY
USING THE INSTRUCTIONS PROVIDED.
2.2 Low-Energy Trip Actuator
The mechanical force required to initiate the tripping
action of a Magnum Circuit Breaker is provided by a
special low-energy Trip Actuator. The Trip Actuator is
Figure 2.1 Tripping Circuit for a Typical Magnum Breaker (Partial)
located under the black molded platform on which the
Digitrip unit is supported. The Trip Actuator contains a
permanent magnet assembly, moving and stationary core
assemblies, a spring and a coil. Nominal coil resistance is
25 ohms and the black lead is positive. The circuit
breaker mechanism assembly contains a mechanism-
actuated reset lever and a trip lever to actuate the tripping
action of the circuit breaker.
When the Trip Actuator is reset by the operating mecha-
nism, the moving core assembly is held in readiness
against the force of the compressed spring by the perma-
nent magnet. When a tripping action is initiated, the low-
energy Trip Actuator coil receives a tripping pulse from
the Digitrip unit. This pulse overcomes the holding effect
of the permanent magnet, and the moving core is re-
leased to trigger the tripping operation via the trip lever.
2.3 Ground Fault Protection
Only the Digitrip 1150 cat# 11LSIG and Digitrip 1150 i cat#
11IEC-EF provide ground fault protection.
2.3.1 General
When the Digitrip 1150 family includes ground fault
protection features, the distribution system characteristics
(for example, system grounding, number of sources,
number and location of ground points, and the like) must
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be considered along with the manner and location in
which the circuit breaker is applied to the system. These
elements are discussed in Sections 2.3.3 through 2.3.6.
The Digitrip 1150 family uses three modes of sensing to
detect ground fault currents: residual, source ground, and
zero sequence (see Table 2.1). Magnum Circuit Breakers
can accommodate all three types except for 4-pole
breakers. The breaker secondary contact inputs B-6 and
B-7 are used to configure the breaker cell positions for the
three schemes. A jumper from B-6 to B-7 programs the
trip unit for either a source ground or zero sequence
configuration. Removing the jumper will program the unit
for a residual ground fault scheme. This jumper resides
on the stationary side of the switchgear assembly. In all
three schemes, the proper current sensor input is re-
quired on the external sensor input terminals B-4, B-5 of
the breaker secondary contacts.
Table 2.1 Digitrip Sensing Modes
Ground (Earth)
Fault
Sensing Method
Breaker
Secondary
Contacts Req’d Applicable Breakers Figure Reference
Digitrip GF
Sensing
Element
Used
Residual No Jumper 3 or 4 pole 2.2, 2.3,2.5, 2.9 element R5
Source Ground Jumper B6 to B7 3 pole only 2.7 element R4
Zero Sequence Jumper B6 to B7 3 pole only 2.8 element R4
Note: This information applies to Trip Units with Ground
2.3.2 Residual Sensing
Residual Sensing is the standard mode of ground fault
sensing in Magnum Circuit Breakers. This mode utilizes
one current sensor on each phase conductor and one on
the neutral for a 4-wire system (shown in Figures 2.2
and 2.3). If the system neutral is grounded, and no phase
to neutral loads are used, the Digitrip 1150 with ground
includes all of the components necessary for ground fault
protection. This mode of sensing vectorially sums the
outputs of the three or four individual current sensors. For
separately-mounted neutrals, as long as the vectorial sum
is zero, then no ground fault exists. The neutral sensor
must have characteristics and a ratio which matches the
three internally-mounted phase current sensors. Available
types of neutral sensors are shown in Figure 2.4. Re-
sidual ground fault sensing features are adaptable to
main and feeder breaker applications.
CAUTION
IF THE SENSOR CONNECTIONS ARE INCORRECT, A
NUISANCE TRIP MAY OCCUR. ALWAYS OBSERVE
THE POLARITY MARKINGS ON THE INSTALLATION
DRAWINGS. TO INSURE CORRECT GROUND FAULT
EQUIPMENT PERFORMANCE, CONDUCT FIELD
TESTS TO COMPLY WITH NEC REQUIREMENTS
UNDER ARTICLE 230-95(C).
2.3.3 Source Ground Sensing
Depending upon the installation requirements, alternate
ground fault sensing schemes may be dictated (see
Figures 2.6 and 2.7). The ground return method is usually
applied when ground fault protection is desired only on
the main circuit breaker in a simple radial system. This
method is also applicable to double-ended systems where
a midpoint grounding electrode is employed. For this
mode of sensing, a single current sensor mounted on the
equipment-bonding jumper directly measures the total
ground current flowing in the grounding electrode
conductor and all other equipment-grounding conductors.
In the CURRENT (protection) submenu, there is a setting
(EXT GND CT RATIO) that enable the proper scaling of
ground pickup and display of ground current if External
Ground CT is employed. This screen is presented when
jumper B-6 to B-7 is presented on a trip unit equiped with
GROUND. External Ground CT ratios of 10, 100, 200,
400, 800, 1000 A:1 and “none” setting are selectable, with
“none” defaulting to the plug In rating. With the correct
ratio selected the GF pickup settings are adjustable in
AMPERES.
2.3.4 Zero Sequence Sensing
Zero Sequence Sensing, also referred to as vectorial
summation (see Figure 2.8), is applicable to mains,
feeders, and special schemes involving zone protection.
Zero Sequence current transformers (4 1/2“ x 13 1/2“ [114
mm x 342 mm] rectangular inside dimensions) are
available with 100:1 and 1000:1 ratios. The EXT GND CT
RATIO setting described above is applicable for zero
sequence.
2.3.5 Multiple Source/Multiple Ground
A Multiple Source/Multiple Ground scheme is shown in
Figure 2.9. In this figure, a ground fault is shown which
has two possible return paths, via the neutral, back to its
source. The three neutral sensors are interconnected to
sense and detect both ground fault and neutral currents.
Call Cutler-Hammer for more details on this scheme.
2.3.6 Ground Fault Settings
The adjustment of the ground fault functional settings
(FLAT response or I2t) is discussed in Section 4.2.1.8.
The effect of these settings is illustrated in the ground
fault time-current curve referenced in Section 9.
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chip has a built-in over-temperature protection feature,
factory set to trip the breaker if the chip temperature is
excessive. If over-temperature is the reason for the trip
the red Long Delay Time LED will flash and the OVER
TEMP TRIP message will appear on the display.
The Digitrip uses the Cutler-Hammer custom-designed
SµRE+chip™, an integrated circuit that includes a
microcomputer to perform its numeric and logic functions.
The principles of operation of the trip unit are shown in
Figure 3.1.
All sensing and tripping power required to operate the
protection function is derived from the current sensors in
the circuit breaker. The secondary currents from these
sensors provide the correct input information for the
protection functions, as well as tripping power, whenever
the circuit breaker is carrying current. These current
signals develop analog voltages across the current
viewing resistors. The resulting analog voltages are
digitized by the SµRE+chip™.
The microcomputer continually digitizes these signals.
This data is used to calculate true RMS current values,
which are then continually compared with the protection
function settings and other operating data stored in the
memory. The embedded software then determines
whether to initiate protection functions, including tripping
the breaker through the Trip Actuator.
3.2 Trip and Operation Indicators
The four cause of trip LEDs on the face of the trip unit,
shown in Figures 1.1 and 3.3 to 3.9, flash red to indicate
the reason for any automatic trip operation. Each LED is
strategically located in the related segment of the time-
current curve depicted on the face of the trip unit. The
reason for the trip is identified by the segment of the time-
current curve where the LED is illuminated. Following an
automatic trip operation, the backup battery continues to
supply power to the LEDs as shown in Figure 3.1. The
LED pulse circuit, also shown in Figure 3.1, is provided to
reduce battery burden and will flash the trip LED approxi-
mately every 4 seconds. Therefore, it is important to view
the unit for at least 5 seconds to detect a flashing cause
of trip indicator. Pushing the Reset button extinguishes
the LED.
2.4 Current Sensors (Magnum Frames less than or equal to
3200A)
The three (3-pole) or four (4-pole) primary current sen-
sors are installed internally in the circuit breaker on the
lower conductors of the breaker. The current sensor
rating defines the breaker rating ( I n). For example,
2000A:1A sensors are used on a 2000A rated breaker.
There are four auxiliary current transformers with a ratio
of 10:1 which further step down the rated current to
100 milliamperes, which is equivalent to 100% ( I n) to the
Digitrip 1150.
The primary current sensors produce an output propor-
tional to the load current and furnish the Digitrip 1150
family with the information and energy required to trip the
circuit breaker when functional protection settings are
exceeded.
WARNING
IF A SET OF CURRENT SENSORS WITH A DIFFER-
ENT RATIO ARE INSTALLED IN THE FIELD, THE
RATING PLUG MUST ALSO BE CHANGED. THE
ASSOCIATED RATING PLUG MUST MATCH THE
CURRENT SENSOR RATING SPECIFIED ON THE
PLUG LABEL. THE CURRENT SENSOR RATING CAN
BE VIEWED THROUGH OPENINGS IN THE BACK OF
THE BREAKER.
2.5 Current Sensors (Magnum Frames greater than 3200A)
The six (3-pole) or eight (4-pole) current sensors installed
in the circuit breaker are located on the lower conductors.
The poles are paralleled and the corresponding current
sensors are also paralleled (see Figure 2.3). For ex-
ample, a 4000A breaker phase rating has two 2000:1
current sensors wired in parallel, which provides an
overall ratio of 4000:2. The auxiliary current transformers
have a ratio of 20:1 for this size breaker which further
3.0 PRINCIPLES OF OPERATION
3.1 General
The Digitrip 1150 family of trip units is designed for
industrial circuit breaker environments where the ambient
temperatures can range from –20°C to +85°C but rarely
exceed 70°to 75°C. If, however, temperatures in the
neighborhood of the trip unit exceed this range, the trip
unit performance may be degraded. In order to insure that
the tripping function is not compromised due to an over-
temperature condition, the Digitrip 1150 microcomputer
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3.2.1 Status LED
This green LED will indicate the operational status of the
protection SµRE A chip of the trip unit. If no external
power is present and the load current through the circuit
breaker exceeds approximately 12 percent (3 phase
power) of the current sensor rating, the LED will flash on
and off once each second indicating that the trip unit is
energized and operating properly. (See Figure 3.1)
If the circuit breaker is in an overload condition this status
LED will flash at approximately 4 times per second while
the overload persists.
3.2.2 Alarm LED
In addition to the green status LED, a yellow alarm LED is
provided to indicate real time alarm conditions existing on
the power system. See Appendix D-16 for the program-
ing of these alarms. Also, if an unusual condition exists
with the Digitrip’s hardwire or firmware this LED will light
with an ALERT or ALARM message.
3.2.3 Trip LED
The trip LED is illuminated on any trip condition. It is also
a real time display and uses the breaker’s auxiliary switch
input for its logic in illuminating this LED. Pushing Reset
or closing the breaker will clear this LED.
3.3 Making Current Release
All Digitrip 1150 Trip Units have a Making Current Re-
lease function. This safety feature prevents the circuit
breaker from being closed and latched-in on a faulted
circuit. The nonadjustable release is preset to a peak
current of 25 x I n, which correlates to approximately 11 x
I n (rms) with maximum asymmetry.
The Making Current Release is enabled only for the first
two cycles following an initial circuit breaker closing
operation. The Making Current Release will trip the circuit
breaker instantaneously and flash the Instantaneous LED
as well as indicating “Making Current Trip” on the display
panel.
3.4 Zone Interlocking
CAUTION
IF ZONE INTERLOCKING IS NOT TO BE USED (I.E.,
ONLY STANDARD TIME-DELAY COORDINATION IS
INTENDED), THE ZONE INTERLOCKING TERMINALS
MUST BE CONNECTED BY A JUMPER FROM TERMI-
NAL B8 TO B9 OF THE BREAKER SECONDARY
TERMINALS SO THAT THE TIME-DELAY SETTINGS
WILL PROVIDE THE INTENDED COORDINATION.
Zone Selective Interlocking (or Zone Interlocking) is
available for the Digitrip 1150 on the Short Delay and
Ground Fault protection functions (see Figure 3.1). The
zone interlocking signal is wired via a single set of wires
labeled Zone In (Zin) and Zone Out (Zout) along with a
Zone Common wire. The Zone Selective Interlocking
function has combined the logic interlocking of Short
Delay and Ground Fault. A zone out signal is sent when-
ever the ground fault pick-up is exceeded or when the
short delay value of 2 x ( I r) is exceeded. Zone Selective
Interlocking provides the fastest possible tripping for
faults within the zone of protection of the breaker and yet
also provides positive coordination among all breakers in
the system (mains, ties, feeders, and downstream
breakers) to limit a power outage to only the affected
parts of the system. When Zone Interlocking is employed,
a fault within the zone of protection of the breaker will
cause the Digitrip 1150 to:
•Trip the affected breaker immediately and, at the same
time,
•Send a signal to upstream Digitrip units to restrain from
tripping immediately. The restraining signal causes the
upstream breakers to follow their set coordination
times, so that the service is only locally disrupted while
the fault is cleared in the shortest time possible.
For an example of how Zone Selective Interlocking may
be used, see Appendix A of this Instructional Leaflet.
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Page 13I.L. 70C1036H01
In this scheme, all breaker secondary currents (at the 100 mA level) are summed together at the PC
board donut transformer to sense ground fault via element R5.
No jumper on secondary contacts B-6, B-7.
Neutral input (if 4-wire) is via contacts B-4, B-5. Neutral current input to secondary contacts is 1A,
equivalent to 1 per unit ground.
Source
L
N
R
5
Digitrip
with GF
R/1
R/1
3
3
2
2
1
1
B-4
Load
Notes:
B-6
10:1
10:1 AUX. CT
B-5
B-7
Black
Trip
Actuator
+
-
L
B
L
C
L
A
1
1
1
Figure 2.2 3-Pole, 4-Wire Breaker with Neutral Sensor Connections for 3200A Frame Using Residual GF Sensing
Source
Load
B-4
B-6
20:1 AUX. CTs
20:1
B-5
B-7
Black
Trip
Actuator
+
-
L
A2
L
B1
L
B2
L
C1
L
A1
L
N1
L
N2
L
C2
2000:1
2000:1
2000:1
2000:1
2000:1
2000:1
2000:1
2000:1
1
2
R
5
Digitrip
with GF
1
2
Notes:
In this scheme, all breaker secondary currents (at the 100 mA level) are summed together at the PC
board donut transformer to sense ground fault via element .
In this scheme, the current sensors in the breaker poles are parallel-wired to achieve a 4000 amp
breaker rating. Other available ratings in this double-wide configuration are 6300A, 5000A,
3200A, 2500A, and 2000A.
R5
Figure 2.3 Neutral Sensor Connections for 4000A Frame Using Residual Ground Fault Sensing
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Page 14 I.L. 70C1036H01
Figure 2.4 Digitrip Neutral Sensor Types
Figure 2.5 4-Pole-3200A Frame Using Residual Ground Fault (Earth-Fault) Sensing
This will defeat all ground fault protection in application for 4 pole breaker.
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Page 15I.L. 70C1036H01
1150
1150
If the breaker is removed from cell (B-6, B-7), jumper disconnected,
Residual Ground setting will apply.
Two standard IA secondary sensors with primary in series and
secondaries parallel may be used.
Figure 2.7 Source Ground Fault Sensing Scheme for 4000A Frame
Figure 2.6 Source Ground Fault Sensing Scheme for 3200A Frame
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Page 16 I.L. 70C1036H01
If the breaker is removed
from cell (B-6,B-7) jumper disconnected, Residual Ground settings will apply.
R5R5
R5
ff
T
M2
M1
B5 B4
I/2
G
I/2
G
I/2
G
I/2
G
I
G
I
G
i
g
I
g
i/2
g
i/2
G
i/2
g
i/2
g
i/2
g
Neutral Sensors Wired
in a Loop Configuration
B5
B5
B4
B4
NN
Internal
Digitrip
Sensor
Ground Fault
Figure 2.8 Zero Sequence Sensing Scheme for 3200A Frame
Figure 2.9 Multiple Source/Multiple Ground Scheme
Breaker M2 trips since this is the only breaker seeing the I fault via element R .
No jumper on B-6, B-7 terminals - all breakers are programmed for standard Residual Ground Fault
protection.
AUX CTs not shown. Wiring needed at system level is shown as a dotted line.
Capital letters represent primary current. Lowercase letters represent secondary current.
The three breakers (M1, M2, and T) must all have the same breaker/sensor rating.
G5
Notes:
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Page 17I.L. 70C1036H01
3.5 PT Module
The PT Module is internally wired in the breaker to the
line side breaker terminals. It provides signal data to
calculate voltage, power, energy and related data. The PT
module is is a three phase, three wire input and three
wire output step down transformer with a wye to wye
hookup.
WARNING
A DIELECTRIC DISCONNECT PLUG LOCATED ON
THE LEFT SIDE OF THE BREAKER IS PROVIDED
WITH THIS MODULE AND IS TO BE REMOVED WHEN
DIELECTRIC TESTING OF THE BREAKER IS CON-
DUCTED.
Figure 2.10 PT Module with Dielectric Disconnect Plug
4.0 PROGRAMMING/VIEWING DIGITRIP 1150 via FRONT PANEL
4.1 Main Menu
4.1.0 Power Up Sequence
When the Digitrip 1150/1150i unit is first powered-up, two
different display messages are possible. If the Digitrip
has been previously commissioned with customer made
settings, the display will alternate between “Cutler-
Hammer DT 1150” and “Customer Settings in Use”
messages. Following this the display will enter into the
main menu. See Appendix D-1.
If Digitrip settings have not been saved previously the trip
unit is using the factory default values. On power up, the
Digitrip will then display”CHANGE FACTORY SETUP?”.
This message will stay on the screen until the user
presses ESCape or the SELect pushbutton or if an alarm
or trip condition is detected.
The ESCape pushbutton action will keep the factory
settings and then will enter the main menu. The factory
setting are listed in Appendix D-23 and are not valid for
most applications. The appropriate settings need to be
defined by a qualified application engineer to provide best
overall protection and coordination for the power system.
A SELect pushbutton action will provide direct entry into
PROGRAM SETTING menu. The first item presented is
the Current CURVE type. LSIG or IEEE or (IEC) current
curve types are possible selections depending on trip unit
style. Pressing SELect again will select the curve pre-
sented in the window center and then step into the
individual elements that need programmed. The VIEW up
and down arrow selects the function while the EDIT up
and down arrow changes value. After they are set they
need to be saved by depressing the SAVE pushbutton.
The saving will place the customer settings in use. Verify
the new settings. See Appendix D-13 for program curve
and D-19 for saving and D-5 for view setting menu.
4.1.1 Pushbutton Definition
View Functions
The “View Functions” group of pushbuttons is located in
the lower right hand side of the unit and includes the View
Up (up arrow), View Down (down arrow), ESCape,
SELect, and Reset buttons.
View Up / View Down - View Up and View Down allow the
user to scroll through any available menu or submenu in
the Digitrip 1150 display.
PT Module
Disconnect Plug
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Figure 3.1 Digitrip 1150 Block Diagram with Breaker Interface
(Load/Lower)
(Line/Upper)
NABC
AUX CTs
Residual
Ground
Detection
Typical Phase and
Ground Sensing
Resistors
Bridge
Circuits Internal
Power
Supply
PT Module
Making Current
Release Circuitry
(See Section 3.3)
Trip
Actuator
LED
Pulse
Circuit
+3V Battery
POWER/RELAY
Module
FET
Trip Cause of
Trip LEDs
S RE+Chip µ
TM
S RE+Chip µ
TM
TA
Current Sensors
4 bit
Latch
Chip
Zone Interlocks Z
IN
Z
OUT
Rating
Plug
Key
Pad
A
Protection
BINCOM
Trans-
ceiver
Accessory
Bus
Aux Relay
Drivers
Trip
Alarm
Status
LED
Aux
Switch
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Figure 3.2 Digitrip 1150 LSI Figure 3.3 Digitrip 1150 LSIA
Figure 3.5 Digitrip 1150i IEC-EFFigure 3.4 Digitrip 1150i IEC
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SELect - The SELect pushbutton selects the submenu for
the blinking selection located in the middle of the display.
ESCape - The ESCape pushbutton brings the user up to
the previous menu in the display. Multiple ESC
pushbutton operation will display Main Menu screen.
Reset - The Reset pushbutton will reset LEDs and screen
data. (See Reset Sequence)
Edit Values
The “Edit Values” group located in the upper left hand
corner of the Digitrip 1150 unit consists of 3 pushbuttons:
Edit Up (indicated by an up arrow), Edit Down (down
arrow) and Save. The Edit Values pushbuttons are
covered by a Plexiglass cover which can be sealed.
Edit Up / Edit Down - Edit Up and Edit Down allow the
user to scroll up or down, respectively, through available
setting values while in any Program Settings submenu.
Save - The Save pushbutton allows the user to save a
group of selected programmable settings from any
submenu in the PGM SET menu. Save is also used in the
TEST Menu. When prompted, pressing Save will begin
the selected test.
Battery Test
The Battery Test pushbutton is located on the right side of
the Digitrip 1150 unit, just above the rating plug door.
Battery Test will light the green LED located above the
pushbutton to ensure proper voltage in the battery.
4.1.2 Blink mode
Middle Blinking
The middle display, if blinking, indicates that the menu
item is selectable or that a submenu exists when a
selection brings up another menu with middle text blink-
ing.
4.1.3 Programming/Viewing Screens
The View Functions control screen viewing, while Edit
Functions apply to programming and storing settings.
ALWAYS VERIFY PROGRAMMED SETTINGS BY
ENTERING VIEW SETTINGS AFTER SAVING.
All screens are viewable depending on the programmed
settings and/or Digitrip 1150 model. In particular, the
METER submenu may be programmed to include any-
where from one to 22 viewable screens when METER is
selected, based on the settings chosen in the PGM
SET\DISPLAY screens. Similarly, certain screens are only
viewable based on availability. For example, in the PGM
SET\AuxRLY menu, the selected relay determines the
programmable groups displayed. See Appendix D.
Depending on the Digitrip 1150 model, certain menus or
screens are not viewable or programmable. When using
the LSI factory style unit, viewing and programming menu
screens involving Ground or Earth settings are not
accessible. When using the LSIG factory style unit,
viewing and programming screens involving Neutral
Protection are not displayed.
4.1.4 Reset Pushbutton Operation
4.1.4.1 Trip Events
A Reset pushbutton operation does the following after a
trip:
a. Clears the cause of trip flashing LEDs (4) after a trip
event
b. Clears the Trip LED
c. Clears Display data
Note: After a Trip Event
1. Observe any Trip LED flashing on Mimic Curve.
2. Observe message on LED display.
3. Push View Down pushbutton to observe Time
Stamp of event and view down to observe any
related data. This data will be stored in Event
Buffer.
4. After any trip condition, the trip unit should be
reset by pressing the Reset Pushbutton.
Reclose breaker as desired.
See Appendix D-4 for possible Trip Events and D-22 for
multiple Alarm condition.
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