Westinghouse KRD-4, Инструкция по установке, эксплуатации и обслуживанию

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TY P E KRV R ELAY
I 2 3
LINE
67
7
TRANSFORMER BANK
NEUTRAL
VECTORS AT 100� P, F, POWER
1• TRIPPING DI RECTI OII
I.L. 41· 137.28
PHASE
67N
I
L
_ _ _
j
USE
52
a
CONTACT IIIIIER TRIP COIL
SUPERY I S I OR L 16HT I S USED.
D£YI CE IIUMBER CHART
67N
2
17 - PIIASE DI RECTI OIIAL OYERCURRUT RELAY , TYPE
�RV
1711 - IIOUIID DI RECTI OIIAL OYERCURRUT RELAY , TYPE KRD
( BOTH 67 AND 67NI
I, lo
-
I RSTARTAREOOS o/c UNIT
D , Do - DI RECTI OIIAL UNIT
ICS U X I L I ARY SWI TCHES
CSl
}
1/ST - SATURATING TRANSFORMER FOR IRST. 0/C UII I T
5 2
-
1'1111ER C I R CU I T BREUER
- IREAlER AU X I L I ARY CONTACT
TC - IREAlER TRI P Cllll
290B768
Fig.
7.
External Schematic of the KRV Relay for Phase P rotection and the K RD Relay for Ground Protection.
housing need not be l oo se n ed for the adju stm ent
since the clamp utilizes a spring- typ e action in
holding the stationary contact in positio n .
3 . Insert tap screw of overcurrent u nit i n highest
t ap . Th e sensitivity adj ustm ent is made by varying
the tension o f the spiral spring attached to the mov­
ing elem ent ass embly . The spring is adju sted by plac­
ing a screwdriver or similar tool into one of the
notches located o n the p eriphery o f the sp ring adj u st­
er and rotating it. The spring adj u st e r is l ocated on
the underside of the bridg e and is held in plac e by a
spring typ e clamp that do es not have to b e loos ened
prior to making the necessary adju stments.
The spring i s to b e adjusted such that the con­
tact will clo s e when the unit is energized at its
maximum torque angl e ( cu rrent l eading the voltage by
30°) with the valu e of current and voltage shown in
Table
1 .
4. T h e magn etic plugs and core are u s ed t o
rev ers e any unwanted spurious torques that m ay be
presen t w h en the rel ay i s e n ergized o n current alone.
The reversing of the spurious torques i s acco m­
plished by u sing the a dj u sting p lugs and core in the
following manner:
Shor t circuit the voltage terminals and apply
current to the operating circuit t erminal s as p er
Tabl e 2.
Plug and core adj ustmen t is then made p er Table
2 such that the spurious torque s are reversed. The
plugs are h el d in position by upper and l ower plug
c lips. Thes e clip s need not b e disturbed in any man­
n er when making the n eces sary adj ustment. The core
assem bly i s hel d in po sition by the clamping action
o f two compressed springs. Thi s allows its po sition
to be change d by in s erting a non-m agn etic t ool into
the slot on the bottom sid e of the unit.
The magn etic plug and core adj ustmen t m ay b e
utilized to po sitively clo s e the contacts o n current
alon e. Thi s m ay be desired on some installations in
9
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