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

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TYP E K RD -4 DI R ECTIONAL O V E RCURRENT
GROUND R ELAY
DI RECTIO NAL UN IT POLA RIZIN G CIRCUIT BURDEN
CIRC UIT
Current
Voltage
RA TING
2 30 t t
amperes
208 t t t
v olts
-�
-
�
----- -
-
-
VOLT AMPE RES L'I
POWER
ANG L E
0
-- -------
1 . 20 3° Lag
2 1 . 0 28° L e ad
-
- � �--- �--�
0
Degrees current l eads or l ags voltage at 1 2 0 vo lts on voltage polari zed units
and 5 amperes o n current polari zed uni t s .
6
Burden of vo ltage polarized unit taken at 1 20 volts . Bur den of cur rent pol ar­
ized unit s tak en at 5 ampe res.
tt One s eco nd rating.
ttt 30 s econd rating. The 1 0 s eco nd ratin g i s 345 vo lts. Th e co n tinuou s rating
is 1 20 vol ts.
Directional Unit (D)
No s etting is required.
I N S T A L L A T I O N
The relay s should be mounted on switchboard
panels o r their equival ent in a location fre e from dirt ,
moisture, excessive vibration and heat. Mount the re­
lay v ertically by means of the two mo unting stud s
for proj ection mounting or by m e an s of the four mount­
ing hol e s on th e flange for the s emi- fl u sh mounting.
Either o f the stud s or the mounting screws may b e
utilized for grounding the relay . The electrical con­
nections may be made directly to the terminals by
means o f screws for steel panel mounting or to ter­
minal studs furnished with the relay for thick pan el
mo unting. Th e terminal stud s m ay be easily removed
or inserted by locking two nuts on the stud s and
then turning the proper nut with a wrench.
For detailed information , refer to I . L . 4 1-076.
A D J U S T M E N T S A N D M A I N T E N A N C E
The proper adj ustments to in sure correct op era­
tion of this relay hav e been made at the factory . Up­
on receipt of the relay , no c u stomer adj u stments,
other than tho s e covered under "SETTINGS, " should
be required.
Acceptance Check
The following check i s recommended to insure
that the relay i s in proper working order.
8
Overcurrent Unit (I)
1. Contact Gap - The gap between the statio nary
and moving contacts with the relay in the de­
energized po sition should be approximat ely
. 0 20. "
2. Minimum Trip Current - The no rmally-closed
co ntact o f the directional unit should b e
blocked o p e n w h e n checking the pick-up o f
t h e overcurrent unit.
The p1ck-up of the ov ercurrent unit c an be
checked by inserting the tap screw i n the
desired tap hole and applying rated tap v alue
current. The contact should clo s e with ±5% of
tap v alue current.
D i rectional Unit (D)
1 . Co ntact G ap - The gap between the station ary
contact and moving contact with the relay i n
t h e de-energized position should b e approxi­
m ately . 0 20 . "
2 . Sensitivity - The r espective directional units
should trip with value of energization and
phase angle relationships as indicated in
Table 1 .
*
3 . Spurious Torque Adjustm ents - There should
be n o s purious closing torques when the oper­
ating circuits are energi zed per Table 2 .
4 . Coupling - Apply 20 amperes to terminals 6
and 7 . M easure voltage across terminal s
4
and
5. Should be l e s s than 20 vo lts.
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