Westinghouse KS Installation, Operation & Maintenance Instructions Manual

TYPE KS OUT-OF-STEP BLOCKING RELAY
B efore
putting
CAUTION
service make sure that all moving parts operate
freely, inspect the contacts to see that they are
clean and close properly, and operate the relay to
check the settings and electrical connections.
APPL ICATION
KS
The Relay (Figure 1 ) is a polyphase compen­
sator distance type relay used with the type KD
distance relay to prevent tripping while out-of-step
or out- of-synchronism conditions exist on the sys­
tem. It does not prevent or delay the type KD relay
from tripping on phase-to-phase faults within its
protective zone that occur during the out-of-step
condition.
CONS TRUCTION
KS
B locking Relay consists of three
The type
air-gap transformers (compensators),
auto-transformers, a cylinder type operating unit, and
a time-delay telephone type relay, all mounted in the
type FT32 relay case.
Com pen sa tor
The compensators which are designated as TA,
:B
-T B , and T c . are two-winding air-gap transform­
T
ers, (Figure 2). The primary, or current winding, has
seven taps which terminate at the tap block. T A and
T c are marked 0.6 , 1 .02, 1 . 6 5 , 2 . 46 , 3 . 68 , 5 . 5 and
:B
8 .2 . T -T B can be set from 3 . 6 ohms to 6 . 1 2 ohms
in steps of 0. 1 8 ohms. Current flowing through the
primary coil provides an MM F which produces mag­
netic lines of flux in the core.
A voltage is induced in the secondary which is
proportional to the primary tap and current magnitude.
This proportionality is established by the cross sec­
tional area of the laminated steel core, the length of
an air gap which is located in the center of the coil,
and the tightness of the laminations. A ll of these
factors which influence the secondary voltage pro­
portionality have been precisely set at the factory.
SUPERSEDES I. L. 4 1 -492. 1
* Denotes change from s uperseded iss ue.
INSTALLATION
1·N S T R V C T I 0 N S
0.51-30 OHMS
protective relays into
two tapped
Westinghouse
• OPERATION
The clamps which hold the laminations should not
be disturbed by either tightening or loosening the
clamp screws.
The secondary winding has a single tap which
divides the winding into two sections. One section
is connected subtractively in series with the relay
terminal voltage. Thus a voltage which is propor­
tional to the line current is subtracted vectorially
from the relay terminal voltage. The second section
is connected to an adjustable loading resistor and
provides a means of adjusting the phase angle rela­
tion between primary current and the induced second­
ary voltage. The phase angle may be set for any
o
value between 60 and 8 0
tor between its minimum and maximum values re­
o
spectively or for 89 by open circuiting the resis­
tor. The factory setting is for a maximum torque
o
angle of 75 current lagging voltage.
A uto-Transformer
The auto-transformer has three taps on its main
S,
winding, which are numbered 1, 2, and 3 on the
tap block. A tertiary winding M has four taps which
may be connected additively, or subtractively to
S
inversely modify the
- 18 +18
to percent in steps of
The sign of M is negative when the R lead is
above the L lead. M is positive when
location which is above the tap location of the R
lead. The M setting is determined by the sum of per
unit values between the R and
per unit values which appear on the tap plate be­
tween taps are 0, . 03, . 09 , and . 06 .
The auto-transformer makes it possible to ex­
pand the basic range of the compensators by a
.
multiplier of Therefore, any relay ohm set-
±
1 M
ting can be made within
ohms to 30 ohms by combining the compensator
:B
taps T A . T -T B , and Tc with the auto-transformer
S
taps A and M A . and S C and Me .
EFFECTIVE DECEMBER 1 967
t.L . 4 1-492. 1 A
• MAINTENANCE
o
by adjusting the resis­
setting by any value from
3
percent.
L
is in a tap
L
lead. The actual
±
1 . 5 percent from 0.5 1