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where:
A
B
See Table V for values of A and B.
*
VOLTS
120
120
120
120
120
120
120
120
120
120
The total potential burden will be the sum of the burden from each unit.
both units will be set for the same reach and maximum torque angle, so it will only be
necessary to calculate the burden for one unit.
of the two potential devices.
The burden measured on any unit may vary plus or minus ten percent from the
instruction book values, due to allowable tolerances on capacitors and coils.
The exact settings to be made on the ohm units in Type CEX57 relays will depend on
the particular application.
When used in blinder applications, the primary objective is to restrict the
tripping area of the tripping units to avoid operation on load impedance.
reach setting should be made so that operation is prevented during maximum load f low or
stable power swing conditions.
will plot parallel to the protected line.
When out-of-step tripping during power swings is required, tripping during stable
swings can be prevented, and the breaker duty minimized, by permitting tripping only
after a favorable angle is reached.
* Indicates Revision
=
=
watts, when T R
100
=
vars, when T R
=
100
MAXIMU M TORQUE
I
HERTZ
ANGLE (LEAD)
s o
6 0
60
100
60
250
6 0
300
6 0
350
s o
50
50
10 0
50
250
50
300
50
350
CALCULATION OF S ETTIN GS
The an gle setting should be made so that the ohm units
GEK-49778
TABLE V
JU MPERS 13-14
AND 15-16
ON
ON
ON
OFF
OFF
ON
ON
ON
OFF
OFF
This value will be the burden on each
Thus, the reach settings to be made will be
9
WATTS
WATTS
-2. 70
5. 20
-3. 50
5. 70
-6 . 50
6 . 30
6 . 20
8. 20
6. 4 0
7. 55
5. 15
-2. 30
5. 90
-3. 33
6. 95
-7. 20
6 . 6 0
4. 83
6. 30
4. 00
Normally
Thus, the
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