26
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
INCOM network interconnections
INCOM sends bursts of data on a 92–115.2 kHz carrier at a
9600 baud rate over twisted pair conductors to interconnect the
many devices comprising the network.
The Digitrip 520MC will light the red LED shown in
Figurt 1
when
transmitting on INCOM.
Recommended cable specifications:
•
Eaton cable catalog #IMPCABLE, Style #2A95705G01
•
Belden 9463 cable family
•
Identical Commscope or Quabbin cables
These bursts of data can be captured and used in a variety of ways
depending upon the manner in which the master computer software
program is written. For example, all the settings can be viewed
via the master computer. Another example is that the data for the
individual phase current values are available on the network, but the
software must select the appropriate data, decode it, and display
it in a useful manner. Following an overcurrent trip operation, the
sequence of coded data varies slightly. The cause of trip, the value,
the phase (or ground) current responsible for the trip are available on
the network.
Section 5: test procedures
Gtntral
m
WARNING
DO NOT ATTEMPT TO INSTALL, TEST, OR PERFORM MAINTENANCE ON
EQUIPMENT WHILE IT IS ENERGIZED. DEATH OR SEVERE PERSONAL
INJURY CAN RESULT FROM CONTACT WITH ENERGIZED EQUIPMENT.
DE-ENERGIZE THE CIRCUIT AND DISCONNECT THE CIRCUIT BREAKER
BEFORE PERFORMING MAINTENANCE OR TESTS.
m
WARNING
ANY TRIPPING OPERATION WILL CAUSE DISRUPTION OF SERVICE
AND POSSIBLE PERSONAL INJURY, RESULTING IN THE UNNECESSARY
SWITCHING OF CONNECTED EQUIPMENT.
m
CAUTION
TESTING A CIRCUIT BREAKER WHILE IT IS IN-SERVICE AND CARRYING
LOAD CURRENT IS NOT RECOMMENDED. TESTING OF A CIRCUIT BREAKER
THAT RESULTS IN THE TRIPPING OF THE CIRCUIT BREAKER SHOULD BE
DONE ONLY WITH THE CIRCUIT BREAKER IN THE TEST OR DISCONNECTED
CELL POSITIONS OR WHILE THE CIRCUIT BREAKER IS ON A TEST BENCH.
Whtn oN otso
Testing prior to startup can best be accomplished with the breaker
out of its cell or in the TEST, DISCONNECTED, or WITHDRAWN
(or REMOVED) cell positions.
Note:
N
Since time-current settings are based on desired system coordination
and protection schemes, the protection settings selected and preset in
accordance with Section 4 should be reset to their as-found conditions if
altered during any routine test sequence.
FuncoiNnal fitld otsoing
m
CAUTION
PERFORMING TESTS WITHOUT THE EATON-APPROVED TEST KIT MAY
DAMAGE THE DIGITRIP UNIT.
Field test kit
Use the test receptacle to verify a functional load test of a major
portion of the electronic circuitry of the Digitrip and the mechanical
trip assembly of the breaker. The testing can determine the accuracy
of the desired trip settings by performing long delay, short delay,
and ground fault functional tests. The Eaton-approved test kit is
listed below.
Model
Test Kit
Digitrip 520 family
Test kit (140D481G02R, 140D481G02RR, 140D481G03, or G04)
with test kit adapter 8779C02G04 or PACB test kit 87C0270
The test port is located on the front left-hand corner of the trip unit
(see
Figurt 1
). To access the port, remove the plexiglass cover from
the front of the circuit breaker. Using a small screwdriver, gently pry
up on the test port cover to remove this item.
