TYPES CA-16 AND CA-26 RE LA YS
64
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6 0
5 6
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-
-
5 2
-
48
Ul
44
UJ
ll:
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g,
40
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UJ
3 2
ll:
ll:
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u
2 8
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20
0
1 6
1 2
8
4
0
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0
2
4
6
8
1 0
1 2
14
16
18
20
2 2
RESTR A I N T C U R R E N T I N A M P E R E S
849A343
Fig. 13. Percentage Slope Curve of the CA- 1 6 and CA-26
Re lays with Six Restraint Windings in Series
2.
M i n i m u m T r i p
The relay sho uld b e level for this test. Minimum
trip current can best be determined with the p erma
nent magnet removed.
Adjust
the spring tension until the relay just
closes its contacts with the follo wing current applied
to terminals
12
and
13
of the relay.
CA- 16
CA-26
0. 15
amperes
1.
25
amperes
3.
P e rce ntage S l o pe C h aract e r i s t i c
*
Co nne c t t he relay per t he test c ircuit of Fig . 1 1 .
Pass 2 0 amperes
for
t he CA- 1 6
and 1 4
amp e r e s for
t he
CA-26
rel ay int o ter minals 9 and 19 of t he rel ay.
Adj u s t t h e pl ug ( when used) in t h e op erating el e ctro
m ag net unt i l the c o nt acts j u st c l o s e wit h t he fol lowing
curre nts into t he op erat ing c ir c u it of t he r e l ays .
CA- 1 6
2 9 . 4
t o
3 4
amperes
CA-26
36
to 4 0 amp e r e s
4.
T i m e C u rve
Place the p ermanent magnet on the rel ay and ap
ply 20 amp eres to terminals
1 2
and
1 3
of the rel ay.
Adjust the k eep er of the p ermanent magnet until the
contacts j ust clo se in the following times:
CA- 16
5 2 ± 5%
milliseconds
CA- 26
72 ± 5%
milliseconds
These times should be the average of
5
readings
5.
lnd i c a t i n g C o n ta c t o r S w i t c h ( IC S )
Close the main relay contacts and �pass sufficient
d-e current thro ugh the trip circuit to close the con
tacts of the ICS. This value of current should be not
greater than the p artic ular ICS tap s etting being
used.
The op eration indicator target should drop
freely.
6 .
I n d i c a t i n g I n s t a n ta n eo u s T r i p U n i t ( l i T )
The core screw must be adjusted to the value of
pick-up current desired. It is recommended that the
liT be set
to
pick-up at a value of current that i s
e qual t o the maximum rms symmetrical external fault
current to the relay.
7.
S e n s i t i v e F a u l t D et e c t o r
Loosen the lock nut at the top o f the element and
run the core scre w down until it iS flush with the top
of the lock nut. Back off the Micarta disc by loos en
ing the two lock nuts. ApplYO.
15
amperes to terminal s
1 4
and
1 5 .
Operate the moving element by hand and
allow the current to hold the moving contact disc
against the st ationary contacts. Now, screw up the
core scre w slo wly. This causes the plunger to move
up , compressing the spring until a point of maximum
deflection is re ached. Further upward motion will
cause the plunger to drop
p art
way out of the coil ,
thus diminishing the spring pres sure on the contacts.
By thus adjusting the core screw up or down the max
imum spr i n g deflection for t h i s value of c urrent m ay
be found. Then l o c k the c ore scre w in p l ac e . N e xt,
adj u st the d e- energized p o sition o f t h e p
1
ungpr by
9
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