I.B. 17555
Page 10
Effective 03/97
inverse time overcurrent phase setting value, the high
load function will begin timing to the time setting select-
ed and the High Load LED will blink. If the current drops
below the 85% value, the high load timer will reset, and
only start again when the 85% value is again reached.
When the high load timer times out, the “High Load”
LED on the front of the relay lights continuously and an
alarm signal is sent over the communication network.
System Frequency Selection: Either 60Hz or 50Hz
may be selected (Table 2.4).
Phase and Ground CT Ratio Selection: The available
CT ratio’s, shown in Table 2.4, range from 5:5 to
5000:5.
Defaults: In the unlikely event of missing or invalid set-
tings, the Operational LED will blink Red instead of
Green and the relay will display “PRGM” in the Settings
Display window. This means that the program of set-
tings should be re-entered and saved.
2-1.5 INTEGRAL TESTING
Digitrip 3000 Protective Relays have a front accessible,
integral field testing capability. This feature introduces a
selected level of internal test current to simulate an over-
load or short circuit. It checks proper functioning of the
relay and verifies that curve settings have been set-up
correctly. The integral test function provides selectable
“Trip” and “No Trip” test settings for both phase and
ground testing. Refer to Table 2.4 for available test set-
tings. The “P” used in Table 2.4 refers to a phase current
test setting, while the “G” refers to a ground current test
setting. “T” in the table means that the test will initiate a
breaker trip. All settings are in per unit current values
times the In value, which is the selected CT rating.
THE TEST MODE SHOULD NOT BE USED TO TRIP
LIVE CURRENT CARRYING CIRCUITS. IF A LIVE
CURRENT OF GREATER THAN 0.1 TIMES THE (I
n
)
VALUE IS FLOWING IN EITHER A PHASE OR
GROUND CIRCUIT, THE TEST MODE IS AUTOMATI-
CALLY EXITED, ACCOMPANIED BY AN ERROR
MESSAGE IN THE SETTINGS/TEST TIME/ TRIP
CAUSE WINDOW.
2-1.6 COMMUNICATIONS
An important function of the Digitrip 3000 Protective
Relay is communications and control via the Cutler-
!
CAUTION
DIP SWITCH SETTINGS
Type
Default Setting
S1:
ON
(Digitrip 3000 IMPACC Buffers)
S2:
OFF
(Program with Breaker Open Only)
S3:
OFF
(Standard Relay Configuration -
OC/Instantaneous)
S4:
ON
(Enable Remote Open/Close)
S5:
OFF
(Reserved)
S6:
OFF
(Reserved)
S7:
OFF
(Reserved)
S8:
OFF
(Disable Download Setpoints)
S9:
OFF
(Manual Reset)
S10:
OFF
(Reserved)
PHASE SETTINGS
Type
Default Setting
Curve Shape:
It
LDPU:
1.0
LDT:
5 sec.
SDPU:
1.5
SDT:
1.0 sec.
INST:
1.75
GROUND SETTINGS
Type
Default Setting
Curve Shape:
It
LDPU:
0.5
LDT:
5 sec.
SDPU:
0.75
SDT:
1.0 sec.
INST:
1.0
MISCELLANEOUS SETTINGS
Type
Default Setting
DISC:
OFF
HILD:
10 sec.
FREQ:
60 Hz
PCT:
500
GCT:
500
Table 2.5 Factory Set Defaults