I.L. 41-748.1F
12
7. SETTING THE RELAY
The type KLF-1 relay requires a setting for each of
the two compensators T
A
and T
C
, for each of the two
auto-transformers primaries S
A
and S
C
, and for the
undervoltage unit.
7.1.
GENERAL SETTING RECOMMENDATIONS
The KLF relay may be applied as a single-zone
device, or two relays may be used to provide
two-zone protection. The single-zone setting may be
fully offset (Zone-1) or may include the origin
(Zone-2). The two-zone application would require a
Zone-1 KLF and a Zone-2 KLF, approximately equiv-
alent to two-zone step-distance line protection. A
generalized external schematic, which is applicable
to either Zone-1 or Zone-2 relays is shown in figure
9. The recommended settings and relative advan-
tages of these various configurations are summa-
rized in Table 1.
The single-zone and two-zone setting recommenda-
tions are modified when two or more machines are
bussed at the machine terminals.The voltage and
time delay considerations are treated in detail in
other sections of this leaflet. The recommended set-
tings are outlined in Table 2.
7.2.
COMPENSATOR (T
A
AND T
C
)
Each set of compensator taps terminates in inserts
which are grouped on a socket and form approxi-
mately three-quarters of a circle around a center
insert which is the common connection for all taps.
Electrical connections between common insert and
tap inserts are made with a link that is held in place
with two connector screws, one in the common and
one in the tap.
A compensator tap setting is made by loosening the
connector screw in the center. Remove the connec-
tor screw in the tap end of the link, swing the link
around until it is in position over the insert for the
desired tap setting, replace the connector screw to
bind the link to this insert, and retighten the connec-
tor screw in the center. Since the link and connector
screws carry operating current, be sure that the
screws are turned to bind snugly.
Compensator T
C
requires an additional setting for
including or excluding the origin of R-X diagram from
the distance unit characteristic. If the desired charac-
teristic is similar to that shown on figure 5(b), the
links should be set vertically in the +T
C
arrow direc-
tion. If a characteristic similar to that shown in figure
5(c) is desired, set links horizontally in the -T
C
arrow
direction.
7.3.
AUTO-TRANSFORMER PRIMARY
(S
A
AND S
C
)
Primary tap connections are made through a single
lead for each transformer. The lead comes out of the
tap plate through a small hole located just below the
taps and is held in place on t he proper tap by a con-
nector screw.
An S setting is made by removing the connector
screw, placing the connector in position over the
insert of the desired setting, replacing and tightening
the connector screw. The connector should never
make electrical contact with more than one tap at a
time.
7.4.
AUTO-TRANSFORMER SECONDARY
(M
A
AND S
C
)
Secondary tap connections are made through two
leads identified as L and R for each transformer.
These leads come out of the tap plate each through
a small hole, one on each side of the vertical row of
M tap inserts. The lead connectors are held in place
on the proper tap by connector screws.
Values for which an M setting can be made are from
-.15 to +.15 in steps of .03. The value of a setting is
the sum of the numbers that are crossed when going
from the R lead position to the L lead position. The
sign of the M value is determined by which lead is in
the higher position on the tap plate. The sign is posi-
tive (+) if the L lead is higher and negative (-) if the R
lead is higher.
An M setting may be made in the following manner:
Remove the connector screws so that the L and R
leads are free. Determine from the following table the
desired M value and tap positions. Neither lead con-
nector should make electrical contact with more than
one tap at a time.
