GE AK-50 - Protective Devices: Undervoltage Tripping; Cut-Off Switches Function; Control Relay Function; Time-Delay Undervoltage Tripping Device

GEI
-
74600
Low
-
voltage
Power
Circuit
Breakers
PROTECTIVE
DEVICES
\
TIME
-
DELAY
UNDERVOLTAGE
TRIPPING
DEVICE
(
Fig
.
21
)
When
any
time
delay
of
3
to
10
sec
-
onds
exists
from
loss
of
voltage
,
the
device
is
considered
satisfactorily
ad
-
justed
.
This
device
is
factory
set
,
non
-
adjustable
in
the
field
.
2
.
Remove
two
screws
(
16
)
.
3
.
Remove
magnet
and
coil
as
-
sembly
.
This
device
is
mounted
to
a
bracket
on
the
leftside
of
the
operating
mecha
-
nism
(
looking
from
the
front
)
.
The
purpose
of
this
device
in
to
trip
the
breaker
,
if
desired
,
when
certain
undervoitage
conditions
exist
.
For
rated
voltage
,
the
armature
(
3
)
is
at
-
tracted
by
the
magnet
(
14
)
.
If
the
volt
-
age
falls
below
the
predetermined
value
the
magnet
(
14
)
releases
the
armature
(
3
)
.
Spring
(
4
)
then
pulls
armature
(
3
)
upward
against
the
restraining
force
of
the
oil
in
cylinder
(
10
)
;
this
action
causes
a
minimum
time
delay
of
three
seconds
.
When
the
spring
overcomes
the
restraining
force
of
the
oil
,
the
armature
engages
screw
(
20
)
thus
ro
-
tating
the
trip
shaft
and
opening
the
breaker
.
4
.
Straighten
laminations
around
shading
ring
(
5
)
.
From
1
/
4
in
.
to
3
/
8
in
.
of
oil
should
be
maintained
in
the
cylinder
at
all
times
.
In
order
to
make
an
inspection
of
the
oil
,
the
cylinder
may
be
un
-
screwed
from
the
cap
.
G
-
E
silicone
oil
9981
LT
40
NV
or
similar
grade
should
be
used
in
the
cylinder
.
5
.
Remove
shading
ring
and
straighten
lower
end
of
coil
clamp
(
13
)
.
6
.
Remove
coil
.
Install
new
coil
in
reverse
order
.
REPLACEMENT
(
Fig
.
21
)
INSTANTANEOUS
UNDER
-
VOLTAGE
TRIPPING
DEVICE
(
Fig
.
21
)
Device
1
.
Disconnect
coil
leads
.
The
instantaneous
undervoitage
de
-
vice
is
mounted
in
the
same
location
and
manner
as
the
time
-
delay
device
.
Its
construction
is
similar
to
the
time
-
delay
device
with
the
exception
of
the
time
-
delay
feature
.
The
omission
of
this
feature
eliminates
the
cylinder
(
10
)
,
plunger
(
12
)
,
connecting
rod
(
11
)
,
clevis
(
7
)
,
bracket
(
1
)
,
and
adjusting
nut
(
8
)
from
the
device
.
2
.
Remove
two
screws
from
bracket
(
1
)
.
(
Bracket
is
omitted
when
instan
-
taneous
undervoitage
device
is
used
.
)
ADJUSTMENTS
(
Fig
.
21
)
An
adjusting
screw
(
20
)
in
the
trip
lever
is
used
to
allow
from
1
/
32
in
.
to
1
/
16
in
.
overtravel
after
tripping
the
breaker
.
3
.
Remove
four
mounting
screws
(
21
)
and
remove
device
.
4
.
Install
new
device
in
reverse
order
.
Adjusting
screw
(
2
)
and
spring
(
4
)
:
are
used
to
adjust
the
armature
so
that
it
will
pick
up
at
80
percent
of
normal
voltage
and
drop
out
between
30
percent
and
60
percent
of
normal
voltage
.
The
adjustments
and
replacement
of
this
device
are
the
same
as
those
de
-
scribed
above
for
the
time
-
delay
under
-
voitage
device
.
Coil
(
15
)
1
.
Disconnect
leads
to
coil
23
Oft
.
-
O
22
.
)
o
21
dx
\
A
2
20
O
I
O
o
2
o
o
3
o
o
4
o
gr
19
3
18
4
17
5
o
1
o
o
2
o
o
3
o
J
2
—
o
4
o
-
v
6
ii
cu
I
[
:
'
8
8
—
•
r
~
n
.
.
O
9
16
-
j
|
—
050
10
i
m
1
;
Q
6
°
1
o
B
12
O
11
15
14
!
3
U
.
V
17
.
Pin
13
.
Clamp
14
.
Magnet
15
.
Coil
16
.
Screws
23
.
Supporting
Bracket
1
.
Bracket
2
.
Adjusting
Screw
and
Nut
3
.
Armature
4
.
Spring
5
.
Shading
Ring
6
.
Pin
7
.
Clevis
9
.
Cap
10
.
Cylinder
11
.
Connection
Rod
12
.
Plunger
22
.
Trip
Paddle
and
Clamp
18
.
Adjusting
Screws
19
.
Locking
Wire
20
.
Adjusting
Screws
8
.
Adjusting
Nut
21
.
Mounting
Screws
Time
-
c
/
e
/
av
undervo
/
faae
triooino
dmvic
*
FiQ
.
21
.
Courtesy of NationalSwitchgear.com