Eaton 520 Manual

Effective October 2009
Instructional Leaflet IL70C1037H05
Digitrip models 520, 520 i ; and 520M, 520M i ,
520MC, 520MC
i trip units for use only in
Magnum and Magnum DS circuit breakers
mWARNING
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. EATON IS NOT LIABLE FOR
THE MISAPPLICATION OR MISINSTALLATION OF
ITS PRODUCTS.
mWARNING
OBSERVE ALL RECOMMENDATIONS, NOTES,
CAUTIONS, AND WARNINGS RELATING TO THE
SAFETY OF PERSONNEL AND EQUIPMENT. OBSERVE
AND COMPLY WITH ALL GENERAL AND LOCAL HEALTH
AND SAFETY LAWS, CODES, AND PROCEDURES.
ote:N 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 that may arise.
If you have any questions or need further
information or instructions, please contact
your local Eaton representative or visit
www.eaton.com.

2
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Contents
Description Page Description Page
Listoffigures .........................................3
Listoftables..........................................4
Section 1: General description of Digitrip trip units . . . . . . . . . . . . 5
Protection...........................................5
Mode of trip and status information . . . . . . . . . . . . . . . . . . . . . . 5
Installationandremoval................................8
Wiring..............................................9
Plexiglasscover......................................9
Ground Alarm/Power Supply Module (520M/MC models only) . 9
Display feature (520M and 520MC only) . . . . . . . . . . . . . . . . . .10
Standards..........................................10
Section 2: General description of Magnum circuit breakers. . . . .11
General............................................11
Low-energytripactuator..............................11
Groundfaultprotection ...............................11
Current sensors (Magnum standard frames). . . . . . . . . . . . . . . 17
Current sensors (Magnum double-wide frames) . . . . . . . . . . . . 17
Section 3: Principles of operation . . . . . . . . . . . . . . . . . . . . . . . . . 17
General............................................17
Trip and operation indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
MakingCurrentRelease ..............................17
Zoneinterlocking....................................17
Section 4: Protection settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
General............................................22
Long delay current setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Longdelaytimesetting...............................23
Short delay current setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Shortdelaytimesetting...............................23
Instantaneous current setting . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Ground fault current setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Ground fault time delay setting . . . . . . . . . . . . . . . . . . . . . . . . . 24
INCOM (Digitrip 520MC models only) . . . . . . . . . . . . . . . . . . . . 25
Section 5: Test procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
General............................................26
Whentotest .......................................26
Functionalfieldtesting................................26
Performance testing for ground fault trip units—
primaryinjection.....................................27
Section 6: Trip unit battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
General............................................29
Batterycheck.......................................29
Battery installation and removal. . . . . . . . . . . . . . . . . . . . . . . . . 29
Section 7: Frame ratings (sensor ratings
andratingplugs) ......................................30
Section 8: Record keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Section9:References..................................31
Magnum and Magnum DS circuit breakers . . . . . . . . . . . . . . . . 31
Time-currentcurves..................................31
Section 10: Digitrip 520MC with
MaintenanceMode ...................................32
General............................................32
Maintenance Mode settings . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Arming Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Remoteindicator....................................32
Choosing the reduction setting . . . . . . . . . . . . . . . . . . . . . . . . . 32
Trippingandtesting..................................32
Appendix A: Zone interlocking examples . . . . . . . . . . . . . . . . . . . 34
Appendix B: Troubleshooting guide. . . . . . . . . . . . . . . . . . . . . . . . 36
Appendix C: Typical breaker master connection diagram . . . . . . . 37
Appendix D: Modbus translator wiring . . . . . . . . . . . . . . . . . . . . . 38

3
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Figure 1. Digitrip 520MC Trip Unit with Rating Plug . . . . . . . . . . . . 5
Figure 2. Installation of the Digitrip Unit into a Magnum Breaker
(Side View). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 3. Installation of the Rating Plug and Mounting Screw . . . . 9
Figure 4. Ground Alarm/Power Supply Module for the
520Mor520MCTripUnits...............................9
Figure 5. Wiring Diagram for 520M and 520MC Models
with Ground Alarm/Power Supply Module . . . . . . . . . . . . . . . . . . 10
Figure 6. Tripping Circuit for a Typical Magnum
Breaker(Partial).......................................11
Figure 7. Three-Pole, Four-Wire Breaker with
Neutral Sensor Connections for 3200A Frame
Using Residual Ground Fault Sensing . . . . . . . . . . . . . . . . . . . . . . 13
Figure 8. Neutral Sensor Connections for 4000A Frame
Using Residual Ground Fault Sensing . . . . . . . . . . . . . . . . . . . . . . 13
Figure 9. Digitrip Neutral Sensor Types (or Source Ground Sensor)14
Figure 10. Four-Pole 3200A Frame (4000A IEC) Using Residual
Ground Fault (Earth-Fault) Sensing . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 11. Source Ground Fault Sensing Scheme
for3200AFrame......................................15
Figure 12. Source Ground Fault Sensing Scheme
for 4000A Frame—Double-Wide . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 13. Zero Sequence Sensing Scheme for 3200A Frame. . . 16
Figure 14. Multiple Source/Multiple Ground Scheme . . . . . . . . . . 16
Figure 15. Block Diagram with Breaker Interface . . . . . . . . . . . . . 18
Figure16.Digitrip520LI................................19
Figure 17. Digitrip 520 LSI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 18. Digitrip 520 LSIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 19. Digitrip 520iWLSIG...........................19
Figure 20. Digitrip 520M MLSI . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 21. Digitrip 520M MLSIA . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 22. Digitrip 520M MLSIG . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 23. Digitrip 520MiMWLSIG........................20
Figure 24. Digitrip 520MC CLSI . . . . . . . . . . . . . . . . . . . . . . . . . . 21
List of figures
Description Page Description Page
Figure 25. Digitrip 520MC CWLSIG . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 26. Digitrip 520MC ARMLSI. . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 27. Digitrip 520MC ARMLSIG . . . . . . . . . . . . . . . . . . . . . . 21
Figure 28. Digitrip 520MC ARMLSIA . . . . . . . . . . . . . . . . . . . . . . 22
Figure 29. Digitrip 520MC ARMWLSIG . . . . . . . . . . . . . . . . . . . . 22
Figure 30. Long Delay Current Settings . . . . . . . . . . . . . . . . . . . . 22
Figure 31. Long Delay Time Settings . . . . . . . . . . . . . . . . . . . . . . 23
Figure 32. Long Time Memory (LTM) Jumper . . . . . . . . . . . . . . . 23
Figure 33. Short Delay Current Settings . . . . . . . . . . . . . . . . . . . . 23
Figure 34. Short Delay Time Settings . . . . . . . . . . . . . . . . . . . . . . 24
Figure 35. Instantaneous Current Settings . . . . . . . . . . . . . . . . . . 24
Figure 36. Ground Fault Current Settings . . . . . . . . . . . . . . . . . . . 24
Figure 37. Ground Fault Time Delay Settings . . . . . . . . . . . . . . . . 25
Figure 38. INCOM Network with Remote Master
ComputerorBIM .....................................25
Figure 39. Functional Test Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Figure 40. Connection Details for Conducting Single-Pole,
Single-Phase Current Tests with the Breaker Removed
fromtheCell.........................................28
Figure 41. Connection Details for Conducting Single-Phase
Current Tests with the Breaker Removed from the Cell. . . . . . . . 28
Figure 42. Alternate Connection Details Using Three Poles
to Develop a Ground Fault Condition . . . . . . . . . . . . . . . . . . . . . . 28
Figure 43. Digitrip Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 44. Typical Trip Function Record Nameplate . . . . . . . . . . . 30
Figure 45. Automatic Trip Operation Record. . . . . . . . . . . . . . . . . 30
Figure 46. Typical Performance Test Record Form . . . . . . . . . . . . 31
Figure 47. Maintenance Mode Wiring—Digitrip 520MC. . . . . . . . 33
Figure 48. Typical Zone Interlocking . . . . . . . . . . . . . . . . . . . . . . .34
Figure 49. Typical Zone Interlocking Connections with
Two Main Breakers (M1, M2) and a Tie Breaker (T) . . . . . . . . . . . 35
Figure 50. Typical Breaker Master Connection Diagram. . . . . . . . 37
Figure 51. Modbus Translator Wiring . . . . . . . . . . . . . . . . . . . . . . 38

4
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
List of tables
Description Page
Table 1. Protection Types Available for Digitrip Trip Units . . . . . . . 6
Table 2. Communication Functions Available for
Digitrip520MCUnits....................................7
Table 3. Digitrip Sensing Modes. . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 4. Ground (Earth) Fault Current Settings. . . . . . . . . . . . . . . 12

5
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Section 1: General description of Digitrip
trip units
DigitripEtrip 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 customer. This instructional leaflet
specifically covers the application of Digitrip trip units (see Table 1)
installed in MagnumEand 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 520, 520M,
and 520MC for ULTstandards and models 520i, 520Mi, and 520MCi
for IEC standards. (See Table 1 for available protection types.) Only
models 520MC and 520MCiprovide communications. (See Table 2
for data that will be communicated.)
The Digitrip 520, 520M, and 520MC trip units may be applied on
both 50 and 60 Hz systems.
Figure 1. Digitrip 520MC Trip Unit with Rating Plug
Auxiliary
Power
Module
Input
Rating
Plug
Protection
Settings
Cause of Trip LED
INCOM
Transmit
LED
Test Port
(covered)
Four-
Character
LCD
All trip unit models are microprocessor-based AC protection devices
that provide true rms current sensing for the proper coordination
with the thermal characteristics of conductors and equipment. The
primary function of the Digitrip trip unit is circuit protection. 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. In addition to the basic protection
function, the Digitrip 520 family of trip units provides mode of trip
information such as:
• Long time trip (overload)
• Short time trip
• Instantaneous trip
• Ground (earth) fault trip (if supplied)
The current sensors provide operating power to the trip unit. As
current begins to flow through the breaker, the sensors generate a
secondary current that powers the trip unit.
The Digitrip 520 family of trip units provides five phase and two
ground (time-current) curve shaping adjustments. To satisfy the
protection needs of any specific installation, the exact selection of
the available protection function adjustments is optional. The short
delay and ground fault pickup 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.
Protection
Each trip unit is completely self-contained and requires no external
control power to operate its protection systems. 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 and Figure 16 through Figure 27.
ote:N The Digitrip 220+ (LI model—Figure 16), 520 (LSI model—Figure
17), 520M (MLSI model—Figure 20) and 520MC (CLSI model—Figure 24)
can be used on three-pole or four-pole circuit breakers for the protection of
the neutral circuit. Only these four models can provide neutral protection,
although models MLSIA, MLSIG, MWLSIG, CLSIA, CLSIG, and CWLSIG can
provide neutral metering. Refer to the National Electrical CodeT(NECT) for
the appropriate application for four-pole breakers.
Mode of trip and status information
On all models, 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 also blink at a faster rate
if the Digitrip is in a pickup, or overload, mode.
Red LEDs on the face of the trip units (for long delay, short delay,
and instantaneous) 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/Battery Test button is pushed. The battery
is satisfactory if its LED lights green when the Battery Check button
is pushed (see Section 6).
ote:N The Digitrip unit provides all protection functions regardless of the
status of the battery. The battery is only needed to maintain the automatic
trip indication.

6
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Table 1. Protection Types Available for Digitrip Trip Units
Digitrip Trip Unit Type 520/520i520M/520Mi520MC/520MCi
Ampere range 200–6300A 200–6300A 200–6300A
rms sensing Yes Yes Yes
Communications No No Yes c
Protection and coordination
Figure number reference 16, 17, 18, 19 20, 21, 22, 23 24, 25, 26, 27, 28, 29
Protection Ordering options LI, LSI, LSIG, WLSIG MLSI, MLSIG, MLSIA, MWLSIG CLSI, CWLSIG, ARMLSI, ARMLSIG,
ARMLSIA, ARMWLSIG
Fixed rating plug (In) Yes Yes Yes
Overtemperature trip Yes Yes Yes
Long delay protection Long delay setting 0.4–1.0 x (In) 0.4–1.0 x (In) 0.4–1.0 x (In)
Long delay time I2t at 6 x (Ir) 2–24s 2–24s 2–24s
Long delay thermal memory Yes Yes Yes
Short delay protection Short delay pickup a200–1000% x (Ir) 200–1000% x (Ir) 200–1000% x (Ir)
Short delay time I2t at 8 x (Ir) 100–500 ms 100–500 ms 100–500 ms
Short delay time FLAT 100–500 ms 100–500 ms 100–500 ms
Short delay time ZSI bYes Yes Yes
Instantaneous Protection Instantaneous pickup a200–1000% x (In) 200–1000% x (In) 200–1000% x (In)
OFF position Yes, except for LI Yes Yes
Making current release Yes Yes Yes
Ground (earth) fault protection Ground fault option Yes Yes Yes
Ground fault alarm No Yes dYes d
Ground fault pickup 25–100% x (In) c25–100% x (In) c25–100% x (In) c
Ground fault delay I2t at 0.625 x (In) 100–500 ms 100–500 ms 100–500 ms
Ground fault delay flat 100–500 ms 100–500 ms 100–500 ms
Ground fault ZSI bYes Yes Yes
Ground fault memory Yes Yes Yes
Neutral protection Yes, Cat LSI only Yes, Cat MLSI only Yes, Cat CLSI only
Maintenance Mode No No Yes g
System diagnostics
Status/long pickup LED Yes Yes Yes
High load alarm/alarm contacts No Yes d, Cat MLSI only Yes d, Cat CLSI only
Cause of Trip LEDs Yes eYes eYes e
Magnitude of trip current No Yes dYes d
Remote ground trip/alarm contacts No Yes dYes d
System metering
Digital display No Four-char. LCD Four-char. LCD
a Additional setting is marked M1 where:
800–3200A Frame: M1 = 14 x /nfor plug amps 200–1250A
M1 = 12 x /nfor plug amps 1600, 2000, 2500A
M1 = 10 x /nfor plug amps 3000, 3200A, 4000A (IEC only)
4000–6300A Frame: M1 = 14 x /nfor plug amps 2000, 2500A
M1 = 12 x /nfor plug amps 3200, 4000, 5000A (see Section 2)
M1 = 10 x /nfor plug amps 6000, 6300A
b ZSI = Zone selective interlock (see Section 3).
c Limited to 1200A; this is only for UL versions, not for IEC models that have “W” in catalog number.
d Requires Ground Alarm/Power Supply Module (see Section 1).
e Four Cause of Trip LEDs—L, S, I, G. Making current release is indicated by the Instantaneous LED.
f 6300A rating for IEC only.
g Units with ARM in catalog number.

7
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Table 2. Communication Functions Available for Digitrip 520MC Units
Catalog Number 5CLSI 5CLSIG 5CLSIA 5WLSIG
Remote information via communications X X X X
Breaker Status
Open/Closed/Tripped X X X X
Address register X X X X
Trip event values
Protection settings X X X X
Current values
Phase A current (amperes) X X X X
Phase B current (amperes) X X X X
Phase C current (amperes) X X X X
Phase N current (amperes) aX X X X
Phase G current (amperes) N/A X X X
Remote messages—alarm
Overload (long pickup) X X X X
High load alarm X N/A N/A N/A
Ground alarm N/A X bX X b
Remote messages—trip
Long delay trip X X X X
Short delay trip X X X X
Instantaneous trip X X X X
Ground trip N/A X N/A X
Overtemperature trip cX X X X
Plug trip (plug problem) dX X X X
MCR trip (making current release trip) eX X X X
High instantaneous trip fX X X X
Slave action commands
Remote reset X X X X
a Breaker must be four-pole or neutral sensor wired.
b Breaker will trip and Alarm contact will operate.
c Overtemperature trip indication via communications—Long LED shown on front panel.
d Plug trip cause through communications—INST LED shown on front panel.
e MCR trip cause through communications—INST LED shown on front panel.
f High instantaneous trip cause through communications—INST LED on front panel.
otes:N
X = Function included
N/A = Not applicable

8
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Figure 2. Installation of the Digitrip Unit into a Magnum Breaker (Side View)
Mouting Boss Steel Mouting Plate
Guide Pin
Digitrip 220/520
Dimple
M04 x 80 mm Mounting Screw
Rating Plug (3 Pins)
Pin 1 Connector K1
0.045 Dia. Pins Exiting
Digitrip Housing
Spring Clip
Connector I1 (520MC only)
Wires with Connectors
M4 Bushing
Ground Alarm/
Power Supply Module
(520M/MC option only)
J3 (3 Point)
J4 (4 Point)
Connectors
Pin 1 Connector K2
Installation and removal
Installation of the trip unit
Align the Digitrip unit with the guide pins and spring clip of the
Magnum circuit breaker. Press the unit into the breaker until the pins
on the trip unit seat firmly into the connector housing and the unit
clicks into place (see Figure 2).
Rating plug installation
mWARNING
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.
mCAUTION
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.
mCAUTION
DO NOT FORCE THE RATING PLUG INTO THE CAVITY.
Use a 1/8-inch (3 mm) wide screwdriver to tighten the M4 screw
and secure the plug and the trip unit to the circuit breaker (see
Figure 3). Close the rating plug door.
mCAUTION
THE M4 SCREW SHOULD BE TIGHTENED ONLY UNTIL IT IS SNUG BECAUSE
THERE IS NO STOP. DO NOT USE A LARGE SCREWDRIVER. A 1/8-INCH
(3 MM) WIDE SCREWDRIVER BLADE IS ADEQUATE.
Trip unit/rating plug removal
To remove the rating plug from the trip unit, open the rating plug
door. Use a 1/8-inch (3 mm) wide screwdriver to loosen the M4
screw. Pull the door to release the rating plug from the trip unit.
To remove the trip unit from the circuit breaker, deflect the spring
clip to release the unit from the steel mounting plate. Pull the unit to
disengage the two or three 9-pin connectors from the circuit breaker
(see Figure 2).

9
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Figure 3. Installation of the Rating Plug and Mounting Screw
Wiring
The internal components of the breaker, and how they are wired out
to the breaker secondary contacts, are shown in the breaker master
connection diagram provided as Appendix C.
Plexiglass cover
A clear, tamper-proof, plexiglass door sits on the breaker cover. This
door 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 ensured by the insertion of a standard meter seal through
the holes in both of the cover retention screws. The plexiglass cover
has an access hole for the Step and Reset/Battery Test pushbuttons.
Ground Alarm/Power Supply Module
(520M/MC models only)
The Ground Alarm/Power Supply Module (see Figure 4) is an
optional accessory for the Digitrip 520M, 520Miand is a required
accessory to enable communications on the Digitrip 520MC and
520MCimodels. The module can be installed beneath the metal
mounting plate of the trip unit in the Magnum circuit breaker.
The module covers the following input voltage ratings: 120 Vac
(7802C83G11), 230 Vac (7802C83G12), 24–48 Vdc (7802C82G12),
and 125 Vdc (7802C82G13). The burden of the Power/Relay Module
is 10 VA.
Figure 4. Ground Alarm/Power Supply Module for the 520M or
520MC Trip Units

10
Instructional Leaflet IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
EATON CORPORATION www.eaton.com
Auxiliary power
When the module is wired as shown in Figure 5, it will provide an
auxiliary power supply so that the 520M/520Mior 520MC/520MCi
liquid crystal display (LCD) will be functional even when the circuit
breaker has no load. A Digitrip 520M or 520MC trip unit without
auxiliary power will not display data until load current reaches
approximately 30% single-phase or 10% three-phase of the
(In) rating.
Figure 5. Wiring Diagram for 520M and 520MC Models with
Ground Alarm/Power Supply Module
Ground alarm
A second function of the module is to provide either a ground trip
or ground alarm only output contact via the relay supplied in the
module. On Digitrip 520M/520MC with ground fault protection, an
LED on the front of the unit also provides an indication of ground
fault trip.
Ground fault trip
When the Ground Alarm/Power Supply Module is used with the
MLSIG model, this unit will provide ground fault trip contacts when
the circuit breaker trips on a ground fault. You must then push the
Reset button on the Digitrip in order to reset the contacts (see
Figure 5, Note 3).
Digitrip 520M/MC
a Contact rating (resistive load):
AC 0.5A at 230 Vac
AC 1A at 120 Vac
DC 1A at 48 Vdc
DC 0.35A at 125 Vdc
b Verify input voltage rating before energizing circuit.
c When used in conjunction with a T. U. Cat.
5MWLSIG, 5MLSIG, 5CWLSIG or 5CLSIG, will
indicate GF trip.
d When used in conjunction with T.U. Cat. 5MLSIA
or 5CLSIA, will indicate GF alarm.
e When used in conjunction with a Trip Unit Cat.
5MLSI or 5CLSI, will indicate High Load alarm.
f When used in conjunction with Trip Unit Cat.
5ARMLSI(G), see Section 10.
Available
Input Voltages
Style
Number b
120 Vac ±10% 7802C83G11
230 Vac ±10% 7802C83G12
24–48 Vdc ±10% 7802C82G12
125 Vdc
(100–140 range)
7802C82G13
Ground Alarm/Power Supply Module
Ground de
Fault Alarm
RemoteControl
Voltage b
A-10
A-11
A-14 A-15
ATR COM J4-1 ATR Volt J4-2 G-ALM2 J4-4 REL COM J4-4 J3-3 Output+
J3-2 Output–
J3-1
G-Alarm
K2-1 K2-3 K2-6
a
Ground c
Fault Trip
MM ALM J4-5
A-9
Maintenance
Mode Active
f
Ground fault alarm
A ground fault alarm alerts a user to a ground fault condition without
tripping the circuit breaker. A red Alarm Only LED on the front of the
trip unit will indicate the presence of a ground fault condition that
exceeds the programmed setting.
The ground fault alarm relay is energized when the ground current
continuously exceeds the ground fault pickup setting for a time
in excess of a 0.1-second delay. The alarm relay will reset
automatically if the ground current is less than the ground fault
pickup (see Figure 5, Note 4).
High load alarm (520M/520MC models only)
The Digitrip 520M and 520MC models of the LSI style only
(Figure 20 and Figure 24) and the module shown in Figure 4
and Figure 5 will provide a High Load Alarm contact instead of
the Ground Alarm function when wired to the breaker secondary
contacts A-10 and A-11. The function activates after a 1-second
time delay when any phase current exceeds 85% of the Irsetting.
Display feature (520M and 520MC only)
The Digitrip 520M/520Miand 520MC/520MCimodels have a user
interface in addition to the green and red LED trip indicators. This
seven-element display performs a metering function and can be
used to monitor load currents.
When the Step button on the face of the trip unit is pressed and
released, the display will show PH 1, for Phase 1 or A, and the
current value. If the Step button is not pressed again, the display
will continue to show the current value for Phase 1. Each time
that the Step button is pressed, the next monitored function will
be displayed. The other real-time readings can be displayed in the
sequence below:
PH 2 Phase 2 (B)
PH 3 Phase 3 (C)
PH 4 Neutral
PH 5 Ground (if ground function is supplied)
HI Highest phase current
OL Overload (Digitrip in Overload mode)
Pushing the Step button while the unit is in the OL mode
will have the unit again display the overload current value
HL High Load Alarm (Cat 5MLSI and 5ARMLSI only)
HELP This message will indicate that the trip unit
is out of calibration and should be replaced at the
earliest opportunity.
In addition, the Digitrip 520MC and Digitrip 520M (product built
with Auxiliary Power Module input pins present, see Figure 1) will
display and freeze the magnitude of the trip value after a trip event
if auxiliary power is available. Use the Step pushbutton to view each
phase value. The highest value that can be presented is 9999. Any
fault currents greater than this value will be shown as HI. Pushing
the Reset pushbutton will clear this data.
Also related to the phase value after a trip event are four dashes
“- - - -”. This message means that the microprocessor could not
complete its writing of the trip event’s magnitude into its nonvolatile
memory. A possible cause of this would be the lack or loss of
auxiliary power during the trip event.
Standards
The Digitrip 520, 520M, and 520MC trip units are listed by
Underwriters LaboratoriesT, under UL File E52096, for use in
Magnum circuit breakers. These same units are recognized by
the Canadian Standards AssociationT(CSAT).
All Digitrip units have also passed the IEC 947-2 test program that
includes radiated and conducted emission testing. As a result, all
units carry the CE mark.