Page 1 0
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Gnd
Fault
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1
:
Available
S
etting
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.1
.
.
2
. .
3
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4
.
.
5
-
- -
Seconds with
1
l
_ - _
I
Fl
a
t R
e
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po
n
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e
I \._
_ _ _
:
_ _ _ _
_1
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l
'
t
Shape
1
/
R
et
u
r
ns
to
Flat
I
R
e
s
p
o
ns
e at
Approximately
I
I
'
1
:
........... ...... I
. 1 *,
.3*,
.s•
I
'
,f
,
'
Seconds with
0.625 1n
"•"In Viewing Window ' ' ' ' I
12t Shape
I ndicates
' .... .._ - -
12t
Shape
' - - -
Fig. 4. 7 Ground Fault Time Delay Settings
Note: See also Section 3.6 on Zone Interlocking.
5.0 TEST PROCEDURES
5.1 General
A
DAN G E R
DO NOT ATTEMPT TO INSTALL, TEST O R PERFORM
MAINTENANCE ON EQUIPMENT WHILE IT IS E NE R
GIZED. DEATH OR SEVERE PERSONAL INJ URY CAN
RESULT FROM CONTACT WITH ENERG IZED EQUI P
MENT.
DE-ENERGIZE THE CIRCUIT AND DISCONNECT THE
CIRCUIT BREAKER BEFORE PERFORMING MAINTE
NANCE OR TESTS.
As illustrated in Figs. 1 and 5, an integral test panel is
provided to test the Digitrip RMS 51 0 Trip Unit.
Several no-trip settings are provided to check the trip unit
operation without actually tripping the circuit breaker.
Breaker Trips
At
6T and GFT
Test Amps
@J
·:Il x ln
Test @
0
Trip
® O
Reset
Unit
0
Status
I.L. 29-8858
Available "Test Amps" Settings
CD "GT" = Phase Current Test at
·
G
xl
n and
TRIPS breaker;
" 1 , 2, 3,
8 or
10"
x I
= Phase
Current Test
·
NO
'b
reaker
TRIP;
"GFT" =Ground Current Test
and
TRIPS breaker;
"GF" = Ground Current Test
-
NO breaker
TRIP.
See Section
5.4.3
for inser·
vice test trip limitations.
®
Push, then release Trip Reset
button to
reset Trip Unit.
Required following all
automatic trip and test
operations.
® Push, then release Test
b
utt
on
to
test. Test operation
begins with release of
pushbutton.
Fig. 5
Integral Test Panel (Lower Right Corner of Trip
Unit)
A
CAUTION
TESTING A CIRCUIT BREAKER UNDER "TRIP CON
DITIONS" WHILE IT IS IN SERVICE AND CARRYING
LOAD CURRENT, WHETHER DONE BY INTERNAL
OR EXTERNAL MEANS, IS NOT RECOMMENDED.
ANY TRIPPING OPERATION WILL CAUSE DISRU P
TION OF SERVICE AND POSSIBLE PERSONAL
INJURY RESULTING FROM UNNECESSARY SWITCH
ING OF CONNECTED EQUIPMENT.
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.
To preserve the primary protection function of the trip
unit, all in-service testing under "Trip" or "No-Trip" condi
tions are only performed at load current values no greater
than 50% of the Long Delay Current Setting, 1,. Any
attempt to conduct in-service testing when the load cur
rent exceeds 50% of 1,, will not be executed by the trip
unit.
Since the Digit rip RMS 51 0 Trip Unit is completely self
powered using energy derived from the current sensors
installed in the circuit breaker, all in-service tests con
ducted should be conducted with the auxiliary control
power module, shown in Fig. 7, plugged into the trip unit.
This action will avoid difficulties caused by load current
levels that are too low to operate the trip unit.
Effective May 1 997
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