Advertisement
TYPE HQS RELAY
letters
can
be
seen when the chassis is re
moved from the case.
The
potential and control circuits thru the
relay are
disconnected from the external cir
cuit
by opening the associated test switches.
Opening the current test switch short-circuits
the
current
transformer
connects one side of the relay coil but leaves
the
other
side
of the coil connected to the
external
circuit
thru
jaws.
This
circuit can be isolated
serting
the
current
ternal
connections),
circuit
test plug, or by inserting a piece of
insulating material approximately 1/32"
into
the
current
test
switches
of the current test switch pair must
be
open
when
using the current test plug or
insulating material
in
circuit the
current; transformer secondary.
A cover operated switch can be supplied with
its
contacts
wired
in series with the
circuit.
This
switch opens the trip circuit
when the cover is removed.
existing type FT cases at
added
to
the
time.
Testing
The
relays can be tested in service, in the
case
but
with the external circuits isolated
or out of the case as follows:
Testing in Service
The ammeter test plug can be inserted in the
current
test
jaws
after opening the
blade switch to check the current thru the re
lay.
This
plug
consists of two
strips
separated by an insulating strip.
ammeter is connected to these strips by termi
nal
screws and the leads are carried out thru
holes in the back of the insulated handle.
Voltages
between the potential circuits can
measured
conveniently by clamping #2 clip
be
leads on the projecting clip lead lug on
contact jaw.
Testing in Case
With
all
blades in the full open position,
4
secondary and
dis
the current test jack
by
in
test plug (without
ex
by
inserting
the
ten
thick
jack
jaws.
Both
this manner to short
trip
This switch can be
any
knife
conducting
The
the
the
ten
circuit test plug can be inserted in
the
contact
jaws.
This
elements
to
a
set of binding posts and com
pletely
isolates
the relay circuits from the
external connections by means of an insulating
barrier
on
the plug.
cuits
are
connected
The
plug
is inserted in the bottom test jaws
with
the binding posts up and in the top test
switch jaws with the binding posts down.
The
external
test
the
relay
elements by #2 test clip leads in
stead
of
the
test plug.
external
test circuit to the current elements
using
clip leads, care should be taken to see
that
the
current test jack jaws are open
that the relay is completely isolated from the
external circuits.
Suggested means
lating
this
circuit are outlined above under
"Electrical Circuits."
Testing out of Case
With
the chassis removed from the base, re
lay
elements
may
be tested by·using the ten
circuit
test plug or by #2 test clip leads as
described
above.
The factory calibration
made with the chassis in the case and removing
the
chassis
from
the case will change
calibration
values by a small percentage.
is
recommended
that
position as a final check on calibration.
INSTALLATION
The
relays should be mounted on switchboard
panels or their equivalent in a location
from
dirt,
moisture, excessive vibration and
heat.
Mount
the relay vertically by means of
the two mounting studs.
may
be utilized for grounding the relay.
electrical
connections
the
terminals
by
means of screws for
panel
mounting or to terminal studs furnished
with
the
relay
for
panel
mounting.
The
easily removed or inserted by locking two nuts
on the studs
and then turning
with a wrench.
The external connections
connects the relay
The external test cir
to these binding posts.
circuits may be made to
When connecting an
so
for
iso
is
the
It
the relay be checked in
free
Either of these studs
The
may be made direct to
steel
ebony-asbestos or slate
terminal
studs may
be
the proper nut
of both
the relay
Advertisement
