TYP ES CA- 1 6 AN D CA-26
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CA-ll
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CA•21 UUT
(FUIT ll£1)
IUISTAIICE
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187A426
Fig. 1 1 . Diagram of Test Connections for the CA- 1 6 one!
CA-26 R elays
C. T i m e C urv e
Apply 20 amperes
to
terminals 1 2 and 13 of the re
lays. The contacts should close in the follo wing
times:
CA- 16
52
±
5% Milliseco nds
Q:A-2 6
72
±
5 % Milliseconds
D.- I n d i c at i n g C o nta ctor S w i tc h ( I C S )
Close the main relay contacts and p as s sufficient
d-e current through the trip circuit to c lo se the con
tact of the ICS. This value of current should not be
greater than the particular ICS tap s etting being used .
The op eration indicator target should drop fre ely.
The contact gap should be approximately . 0 4 7
inch between t h e bridging moving contact and t h e ad
justable stationary contacts. The bridging moving
contact should touch both stationary contacts simul
taneously.
E . I n d i c a t i ng I n s t a n ta n e o u s U n it ( I I T ) - W h er e s u p p l i e d )
The core screw which i s adjustable from the top
of the trip unit determines the pick-up value. The
trip unit has a nominal ratio of adjustment of 1 to 4
and an accuracy within the limits of 10%.
The making of the contacts and target indic ation
should occur at approximately the same instant.
Position the stationary contact for a minimum of 1/3 2
inch wipe. The bridging moving contact should touch
both stationary cont act s simultaneously. Apply suf
ficient current to operate the liT.
8
32
28
24
..
"'
"'
..
� 20
;!';
1 6
1 2
8
4
CA·26
CA-16
20
40
60
8 0
RESTRAINT CURRENT IN AMPERES
100
Curve
537958
Fig. 12. Percentage Slope Curve of the CA- 1 6 one! CA-26
Relays with One Restraint Winding
F . S e n s i t i v e F a u l t D etec to r (wh ere s u p p l i e d )
Apply current to terminals 14 and 1 5 of the re
l ay. The fault detector should operate between the
limits of 0. 1 4 2 to 0. 158 amperes.
R o u t i n e M a i nte n a n c e
All contacts should be periodically cleaned.A c on
tact burnisher S# 18 2A836HO
1
is recommended
for
this p urpose. The use of abrasive material for clean
ing contacts is not recommended , bec ause o f the
danger of embedding small p article s in the face of
the soft silver and thus impairing the contact.
C A L I B R A T I O N
Use the following proc edure for calibrating the
relay if the relay has been tak en apart for repairs or
the adjustments disturbed. This p rocedure should
not be used until it is apparent that the relay is not
in prop er working order. ( Se e "Accep tance Chec k").
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