21
Instruction Leaflet
IL01301051E
effective September 2013
Operating Manual for Series NRX
Trip Units - Digitrip™ 520/520M
EATON
www.eaton.com
Section 4: Test procedures
General
•
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.
ANY TRIPPING OPERATION WILL CAUSE DISRUPTION OF SERVICE
AND POSSIBLE PERSONAL INJURY, RESULTING IN THE UNNECESSARY
SWITCHING OF CONNECTED EQUIPMENT.
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.
When oN oeso
Testing prior to startup can best be accomplished with the
circuit breaker out of its cell or in the TEST, DISCONNECTED, or
WITHDRAWN (or removed) cell positions.
Noee:
N
Since time-current settings are based on desired system coordination and
protection schemes, the protection settings selected and preset in accordance
with Section 3 should be reset to their as-found conditions if altered during any
routine test sequence.
FuncoiNnal field oesoing
•
CAUTION
PERFORMING TESTS WITHOUT THE EATON-APPROVED TEST KIT MAY
DAMAGE THE DIGITRIP UNIT.
FuncoiNnal oeso kio (handheld)
Description of handheld test kit
A battery-powered test kit is available and capable of testing the
functional trip elements for trip units 520/520M and for Series NRX
circuit breakers, including power up, instantaneous trip, short delay
trip, and ground (earth) fault trip. These test selections are chosen with
the switch labeled “Select Test” located in the upper right-hand corner
of the test kit. The test currents are not adjustable for this test kit.
The catalog number for this functional test kit is MTST230V or IZMX-
TEST.
Figure 19. FuncoiNnal Teso Kio
Teso prNcedure
•
CAUTION
BEFORE PLUGGING A TEST KIT INTO THE TEST PORT, PLACE THE LTM
JUMPER IN THE INACTIVE POSITION (SEE FIGURE 16). AFTER TESTING,
RETURN THE LTM JUMPER TO ITS ORIGINAL POSITION.
Complete procedural instructions for Eaton’s functional test kit can be
found in IL01301067E, which is packaged with each test kit.
Noee:
N
YNu can access ohe oeso kio I.L. by gNing oN EaoNn’s Websioee: hoope://
www.eaoNn.cNm and search “IL01301067”.
Once the testing procedure is completed, disconnect the test cable
from the test kit to prevent accidental operation and battery drainage.
Reset the trip unit settings to its original condition. Reposition the LTM
jumper to the as-found condition. Install the small cover on the Digitrip
and reposition the plexiglass cover.
Currents
Each test selected by the Select Test switch on the test kit supplies a
fixed milliampere/millivolt value. The rating plug, such as the long delay
setting, will affect the per unit (I
R
) current value and the response of
the Digitrip unit.
Batteries
The functional test kit contains a total of seven 9V batteries. A lithium
ion cell is the preferred battery type for BAT A and is attached to the
main pc board of the test kit. If either LED does not light or lights only
dimly, replace the appropriate battery or batteries.
Noee:
N
The functional test kit also includes a 120/230 Vac auxiliary power cord
that plugs into the trip unit. This can be used to conserve test kit battery life.
GrNund (Earoh) Faulo PerfNrmance Tesoing
For additional information and record keeping on performance testing
for ground fault trip units see Appendix D.