TYPES CA- 1 6 AND CA-26 RELAYS
64
56
48
40
32
CA-26
CA• I 6
24
1 6
8
4
8
1 2
16
2 0
2 4
RESTRAINT
CURRENT
I N AMPERES
Curve
537959
Fig. 13. Percentage Slope Curve of the CA- 1 6 and CA-26
Relays with Six Restra int Windings in Series
1.
C o ntacts
Adjust the adjustable stop screw o n the upper
disc of the relay so that a contact sep aration of
0. 050 inch is obtained between the moving contact
and the stationary contact. Lock the screw with the
nut provided for the purpose.
2 .
M i n i m um T r i p
The relay should b e level for this test. Minimum
trip current can best be determined with the perma
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
0 . 15 amperes
CA- 26
1. 25 amperes
3.
P e r c e ntage S l o p e C h a r a c te r i s t ic
Connect the relay p er the test circuit of Fig . 1 1 .
I.L. 41 ·337.2C
Pass 19 amperes for the CA- 16 and 38 amperes for
the CA-26 relay into terminals 1 2 and 13 of the re
l ay. Adjust the plug in the operating electromagnet
until the contacts just clo se with the following cur
rent� into the re straint circuits of the relays.
CA- 16
16 to 17 amp eres
CA- 26
14 to 15 amperes
4.
T i m e C urve
P l ace 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 ermanent magnet until the
contacts j ust clo se in the following times:
CA- 16
52 ± 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 S w i t c h ( IC S )
Close the main relay contacts and p as s sufficient
d-e current through the trip circuit to clo se 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
fre ely.
6. I n d i c a t i n g I n sta n ta n eo u s T r i p U n 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 p ick-up at a v al ue of current that i s
e qual t o the maximum rms symmetrical external fault
current to the relay.
7.
S e n s it i v e F a u l t D et e c t o r
Loosen the lock nut at the top of 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. Apply 0. 15 amperes to terminals
14 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 slowly. This causes the plunger to move
up , compressing the spring until a point of maximum
deflection is re ached. F urther upward motio n 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-
9
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