TYP ES CA- 16 AND CA-26 R E LA YS
6
6
4
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6
2
8
4
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3
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u 2
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6
2
8
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20
6
2
8
4
CA - 2 6
0
2
4
6
8
10
1 2
14
16
18
20 22
RESTRAINT CURRENT IN AMPERES
849A343
Fig. 13. Percentage Slope Curve of the CA- 1 6 and C A-26
Relays with Six Restra int Windings in Series
2.
M i n i m um T r i p
The rela,y should b e level for this test. Minimum
trip current can best be detennined with the p enna
nent magnet removed.
Adjust
the spring tension until the relay just
closes its contacts with the following current applied
to tenninals 1 2 and 13 of the relay.
CA- 16
0. 15 amperes
CA- 26
1. 25 amperes
3.
P e r c e ntage S l op e C h a r a c te r i s t i c
Connect the relay p er the test circuit o f Fig. 1 1 .
P ass 20 amperes for the CA- 16
and
14 amperes for
the CA-26 rela,y into tenninals 9
and
19
of
th
e
re
la,y. Adjust the plug
in
the
op erating electromagnet
until the contacts just close \1/ith
the
follo wing cur
rents into the
op erating
circuit
of
the rel a.Ys.
CA- 1 6
2 9 . 4
to
34
amperes
C
A
-
2
6
36
to
40
amperes
4.
T i m e C urve
Place the p ermanent magnet on the rel ay and ap
ply 20 amp eres to terminals 1 2 and 13 of the relay.
Adjust the k eep er of the p ennanent magnet until the
contacts just 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.
l n d i c a t i n g C o n ta c t o r Sw i t c h ( IC S )
Close the main rela,y contacts and pass sufficient
d-e current through the trip circuit to close the con
tacts of the
res.
This value of current should be not
greater than the p artic ular ICS tap setting 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 it ( 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 is
e qual to the maximum rms symmetrical external fault
current to the relay.
7.
S e n s it i v e F a u lt D ete c t o r
Loosen the lock nut at the top of the element and
run the core screw 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. Apply O. 15 amperes to tenninals
1 4 and 15. 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 screw slo wly. This causes the plunger to move
up , compressing the spring until a point of maximum
deflection is reached. Further upward motio n will
caus e 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 spring deflection for this value of curre nt may
be found. Then lock the c ore screw in place. Next,
adj ust
the d e- energized position
of the
p l unger by
9
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