()
GEK-45375
These
tests
are intended
to
insure
that
the
relays
have not deviated
from
their
original
setting.
If
deviations
are encountered the
relay
must
be
retested
and
serviced
as
described in
this
manual.
l.
Perform pickup
test
as
described in the
"Installation
Section"
for
the tap
settin~
in
service.
2. Perform the time
tests
as
described 'in the
"Installatfon
Section".
HI-SEISM)C
INSl_'_!\!iTANEOUS
Ufil_l
·1.
Check
that
the instantaneous
unit
picks
up
at
the des-ired
current
level,
as
outlined
in the
"Acceptance Test
Section".
HI-SEISMIC
TARGET
AND
SEAL-IN
UNIT
1.
Check
that
the
unit
picks
up
at
the values
shown
in Table
ll.
2.
Check
that
the
unit
drops out
at
25%
or
more
of tap value.
CONTACT
CLEANING
For
cleaning
relay
contacts,
a
flexible
burnishing tool should
be
used. This
consists
of
a flex··
ible
strip
of
metal with
an
etched-roughened
surface
resembl'ing in
effect
a
superfine
file.
The
polishing
action
is
so
delicate
that
no
scratches
are
left,
yet
it
•till
clean
off
any
corrosion
thoroughly
and
rapidly.
Its
flexibility
insures
the cleaning of the actual points
of
contact.
Do
not
use knives,
files,
abrasive
paper or c 1 oth
of
any
kind to clean re 1
ay
contacts.
SYSJQLTEST
Although
this
instruction
book
is
primarily
written
to check
and
set
the
IFC
relay,
overall
functional
tests
to
check the system operation
are
recommended
at
intervals
based
on
the
customer's
experience.
.
SE.RVICING
If
it
is
found during
installation
or
periodic
testing
that
the time
overcurrent
unit
is
out
of
limits,
the
unit
may
be
recalibrated
as
follows:
Pickup Tests
Rotate time
dial
to
No.
0 time
dial
setting
and
check
by
means
of
a
lamp
that
the
contacts
just
c 1 ose.
The
point
at
whic~
the contacts
j'Jst
close
can
be
adjusted
by
running the
stationary
contact
brush
in
or
out
by
means
of
its
adjusting
screw. This screw should
be
held
securely
in
its
support.
.With
the
contacts
just
closing
at
No.
0 time
setting,
there
should
be
sufficient
gap
between the
stationary
contact
brush
and
its
metal backing
strip
to
insure
aoproximately 1/32" wipe.
The
p-ickup
of
the
unit
for
any
current
tap
setting
is
adjusted
by
means
of
a
spring-adjusting
ring.
By
turning
the
ring
the operating
current
of
the
unit
may
be
brought
into
agreement with
the
tap
setting
employed
if
for
some
reason,
this
adjustment
has
been
disturbed.
This adjustment also permits
any
desired
setting
intermediate between the various tap
settings
to
be
obtained.
If
such adjustment
is
required,
it
is
recommended
that
the higher tap
setting
be
used.
It
should
be
noted
that
the
relay
will
not necessari'lv aqree •iiith the time
current
characteristics
of
Figures 6-8
and
20-22,
if
the
relay
has
been
adjusted to pickup
at
a value
other
than tap
value,
because the torque level
of
the
relay
has
been
changed,
Connect the operating
coil
terminals to a source
of
the proper frequency
and
good
waveform
having
a
vo
1 taqe
of
11
0
or
more, with
resistance
1
oad
boxes
for
setting
the
current.
See
Test C'ircui t
Figure 16.
13
Courtesy of NationalSwitchgear.com
To Next Page
Loading...
Need help?
General
