GE M60 Instruction Manual page 292

5.6 GROUPED ELEMENTS
The phase directional element responds to the forward load current. In the case of a following reverse fault, the ele-
ment needs some time – in the order of 8 ms – to establish a blocking signal. Some protection elements such as
NOTE
instantaneous overcurrent may respond to reverse faults before the blocking signal is established. Therefore, a
coordination time of at least 10 ms must be added to all the instantaneous protection elements under the supervi-
sion of the phase directional element. If current reversal is of a concern, a longer delay – in the order of 20 ms –
may be needed.
SETTING
PHASE DIR 1
FUNCTION:
Disabled=0
Enabled=1
SETTING
AND
PHASE DIR 1
BLOCK:
Off=0
SETTING
PHASE DIR 1 SOURCE:
IA
Seq=ABC Seq=ACB
VBC VCB
5
SETTING
PHASE DIR 1 BLOCK OC
WHEN V MEM EXP:
No
Yes
PHASE B LOGIC SIMILAR TO PHASE A
PHASE C LOGIC SIMILAR TO PHASE A
5-154
I 0.05 pu
SETTING
PHASE DIR 1 POL V
THRESHOLD:
-Use V when V Min
-Use V memory when
MEMORY TIMER
V < Min
1 cycle
V MINIMUM
USE ACTUAL VOLTAGE
USE MEMORIZED VOLTAGE
Figure 5–81: PHASE DIRECTIONAL SCHEME LOGIC
M60 Motor Protection System
SETTING
PHASE DIR 1 ECA:
RUN
AND
0
Vpol
1
1 sec
5 SETTINGS
FLEXLOGIC OPERAND
OR PH DIR1 BLK
FLEXLOGIC OPERAND
PH DIR1 BLK A
OR
AND
FLEXLOGIC OPERAND
PH DIR1 BLK B
FLEXLOGIC OPERAND
PH DIR1 BLK C
827078A6.CDR
GE Multilin