GE STD16C - Page 21

GEK—45307
Any
change
in
R3
to
give
the
desired
slope
will
have
small
effect
upon
minimum
pickup
and
harmonic
restraint.
However,
after
the
slope
setting
has
once
been
set)
any
adjustment
of
minimum
pickup
will
change
the
slope
characteristics.
The
slope
set
points
must
then
be
rechecked,
to
make
sure
that
they
are
still
in
accordance
with
Table
III.
INSTANTANEOUS
OVERCURRENT
UNIT
This
unit
is
located
at
the
upper
right-hand
side
of
the
relay.
Its
setting
may
he
checked
by
passing
a
high
current
of
rated
frequency
through
terminals
5
and
6,
The
unit
should
pick
up at
B times
the
tap
rating)
as described
under
CHARACTERISTICS.
If
the
setting
is
incorrect,
it
may
be
adjusted
by
loosening
the
lock
nut
at the
top
of
the
unit
and
turning
the
cap
screw
until
the
proper
pickup
is
obtained.
In
making
this
adjustment,
the
current
should
not
be
allowed
to
flow
for
more
than
approximately
one
second
at
a
time.
DROPOUT
OF
MAIN
UNIT
After
the
other
tests
are
complete,
check
the
dropout
of the
main
unit,
as
described
in
the
ACCEPTANCE
TESTS
section.
LOCATION
The
location
should
be clean
and
dry,
free
from
dust
and
excessive
vibration,
and
well
lighted
to
facilitate
inspection
and
testing.
MOUNTING
The
relay
should
be
mounted
on
a
vertical
surface.
The
outline
and
panel
drilling
dimensions
are
shown
in
Figure
18.
CONNECTI
ONS
Internal
connection
diagrams
are
shown
in
Figures
10
and
11.
Typical
wiring
diagrams
are
given
in
Figures
1,
2
and
3 for
differential
applications.
Of
course,
any
through-current
transformer
winding
may
be
used
for
any
power
transformer
winding,
provided
the
taps
are
properly
chosen.
When
the
relay
is
mounted
on
an
insulating
panel,
one
of
the
steel
supporting
studs
should
be
permanently
grounded
by
a
conductor
not
less
than
No.
12
AWG
gage
copper
wire,
or
its
equivalent.
Every
circuit
in
the
drawout
case
has
an
auxiliary
brush.
(See
Figure
12.)
This
is
the
shorter
brush
in
the
case,
which
the
connecting
plug
should
engage
first.
On
every
current
circuit
or
other
circuit
with
shorting
bars,
make
sure
the
auxiliary
brushes
are
bent
high
enough
to
engage
the
connecting
plug
or
test
plug
before
the
main
brushes;
otherwise
the
CT
secondary
circuit
may
be
opened
where
one
brush
touches
the
shorting
bar
before
the
circuit
is
completed
from
the
plug
to
the
other,
main
brush.
21