Time Overcurrent Relays Type lAC
1
2
I NDUC T I ON
U N I T
I N STANT.
U N I T
I N STAN T ,
UN I T
10
" •
SHORT F I NGER
F i g . 1 7 I nternal Connec t i ons fo r the Type
I AC52B Re l ay Fron t V i ew
V A R I A B L E R E S i S T A N C E
O R L O A D B O X
� ----
1
S Y N C H R O N O U S
T I M E R
S W I T C H
I
I
I
I
I
I
I
I
1 1 5 V O L T S
R A T E D F R E Q U E N C Y
I
'- - - ...
--
- - - -
-.
I
1
I
t- - - - - -t --,
i
I
I
I
,
-
.... \ 1 I
I
L./
y 1--'
I
I
\
1
I
, _ _.,.,
F R E Q U E N C Y M E T E R
( W H E N R E Q U I R E D )
F i g . 1 8 Tes t i n g Connect i on s for Type l AC
Rel ays s uch as Type I AC5 1 A
INSTALLATION
LOCATION
The location should be clean and dry free from
d u s t and excessive vibration, and wel
i
lighted to
facilitate inspection and testing
MOUNTING
The relay should be mounted on a vertical sur
face. The outline and panel diagrams are shown in
Figures
19
and
20.
CONNECTIONS
Internal connection diagrams for the various
relay types are shown
in
Fig.
11
to
17
inclusive .
�"""'.
Typical wiring diagrams are giVen in�ig. _i to�
inclusive .
One of the mounting studs or screws should be
permanently grounded by a conductor not less than
No.
12
B&B
gage copper wire or its equivalent.
INSP ECTION
At the time of installation, the relay should be
inspected for tarnished contacts, loose
or
other imperfections .
If
any t r o u b l e is
it
should be corrected in the manner described
''Maintenance''.
ADJUSTMENTS
TARGET
&
S EAL ·I N ELEM ENT
For trip coils operating on currents ranging
from 0.2 up to 2.0 amperes at the minimum control
voltage, set the target and seal-in tap plug in the
0.2 -ampere tap.
For trip coils operating on currents ranging
from 2 to 30 amperes at the minimum control volt
age, place the tap plug in the 2 -ampere tap.
The tap plug is the screw holding the right -hand
stationary contact of the seal -in element. To change
the tap setting, first remove the cmmecting plug.
Then, take a screw from the left -hand stationary
12
contact and place
it
in
the desired tap. Next remove
the screw from the other tap, and place
it
in the
left-hand contact. This procedure is necessary to
prevent the right -hand s t a t i o n a r y contact from
getting out of adjustment. Screws should not be in
both taps at the same time as pickup for d-e will be
the higher tap value and a -c pickup will be increased.
M AIN ELEM ENT
CURRENT SETTING
The current at which the contacts operate may
be changed by changing the position
of
the tap plu
,
in
the tap block at the top of the relay. Screw th
'
""""·
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