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T YPE COQ RELAY
(dead-ended)
under
the
screw located
in
the
contactor switch.
CONTACT CIRCUIT CONSTANTS
Universal Trip Circuit
Resistance of 0.2 ampere Target .... 2.88 ohms
Resistance of 2.0 ampere
Contactor Switch .................
Resistance of Target and
Switch in Parallel ............... 0.23 ohms
INSTALLATION
The relays
should
be
board panels or their equivalent in a location
free from dirt, moisture,
and heat.
Mount the relay vertically by means
of the two mounting studs for the type FT pro
jection case or by means of the four
holes on the flange for the semi-flush type FT
case.
Either of the
screws
may
be
utilized
relay.
The electrical connections may be made
direct to the terminals by means of screws for
steel panel mounting or to terminal studs fur<>
nished
with the
relay for ebony-asbestos
slate panel mounting.
be easily
removed or inserted
nuts on the
studs and then turning the proper
nut with a wrench.
SETTINGS
There are
two
settings
value and
the time
dial settings.
protection of generators from
tive sequence currents,
determined by the type of machine and the full
load current rating of the machine.
Tap Value Setting
This setting is determined by
current of the
generator expressed in current
transformer secondary amperes.
6
small
filister head
Micarta
base
of
the
0.25 ohms
mounted
on
switch
excessive vibration
mounting
studs or the
mounting
for
grounding
the
or
The terminal studs may
by locking two
namely, the tap
For
the
excessive nega
the settings
must be
the full load
Time Dial Setting
Settings of the
time dial are determined by
the type of machine to be protected.
�
dial indicates a I
T
=
for which the
relay protects.
time dial, the relay
can be
�
generators with
I
T constants
"30" to "90" as shown in Fig. 3.
ADJUSTMENTS AND MAINTENANCE
All the relays
should be
odically and the
time of
checked at least
once every
such other time
intervals as
by experience to be suitable to the particular
application.
Phantom loads should not be used
in testing induction-�ype
the resulting
distorted
which produces an error in timing.
All contacts should be cleaned periodically.
A contact burnisher S#l8 2A836H01 llirecommended
for this purpose. The use of abrasive material
for cleaning
contacts is not recommended, be
cause of the danger of
cles
in
the face of the soft silver and thus
impairing the contact.
The proper
adjustments
operation of this relay
factory and should
not
after receipt by the customer.
ments have
been changed
apart for repairs,
the instructions
should be followed.
Adjust the
stationary
its adjusting screw
such
spring is just free of
By means of the
time dial,
contacts until
they deflect
contacts approximately
index pointer
such that
mark on the time dial.
contact by means of its adjusting
the moving and stationary contacts just touch.
This adjustment is to set "O" on the time dial
and provide follow for the contacts.
The time
K
curve of a generator
By t urning the
used to
protect
varying
from
inspected
peri-
operation should be
six months or at
may be dictated
relays
because
of
current
wave
form
embedding small parti
to
insure
correct
have been made at the
require
readjustment
If the adjust-
or the
relay
taken
below
contact
by means of
that
the
contact
the front spring stop.
move the
moving
the
stationary
1/64 inch.
Set
the
it points to the "O"
Adjust the stationary
screw until
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