Westinghouse 41-759.3 Instructions Manual

TYPE AR HIGH SPEED AUXILIARY RELAY
CAUTION:
Before putting
service, remove all blocking which may have been
inserted for the purpose of securing the parts during
shipment. Make sure that all moving parts operate
freely. Inspect the contacts to see that they are
clean and can close properly. Operate the relay to
check the settings and electrical connections.
APPLICA TION
The high threshold AR relay is a sensitive high
speed auxiliary relay with 4 N .0. contacts designed
to be secure against misoperation due to inadvertent
grounding of a station battery or the trip lead. With
the battery balanced with respect to ground, the
maximum momentary voltage that can be applied to
an auxiliary relay for either of these grounds is half
battery voltage . The operating level of the high
threshold AR exceeds these levels .
CONSTRU C TION AND
AR Unit
The relay consists of four
screws, four leaf spring moving contacts, a moving
armature and card assembly, which operates the
moving contacts; a U shaped laminated core, a coil,
a frame, a molded insulation block and a series
resistor. Refer to Fig. 1 and
connected around the coil to eliminate the genera­
tion of induced voltages upon interruption of the
coil circuit.
The armature and card assembly slip over a hinge
pin which is inserted in the laminations . The moving
and stationary contacts are mounted on the molded
insulation block. The molded block and coil and
lamination assembly are mounted to the frame. All
contacts are fine silver .
When the coil and resistor are energized, the
armature is attracted to the laminations. The card
moves with the armature
moving contacts. The tension of the moving contacts
is the resetting force.
S U PERSED ES L914464
Complete Revision
INSTALLATION
INSTRUCTIONS
HIGH THRESHOLD DESIGN
protection relays into
OP ERATION
stationary contact
2.
A zener diode is
thereby operating the
Westinghouse
OPERATION
•
High speed operation is obtained by the low
inertia of the moving parts, a sensitive electromag­
net, and the proper L/R ratio of the operating circuit.
Operation Indicator (0.1.)
The de operation indicator is a small clapper
type device. A magnetic armature is attracted to the
magnetic core upon .energization
During this operation two fingers on the armature
deflect a spring located on the front of the switch,
which allows the operation indicator target to drop.
The front spring, in addition to holding the target,
provides restraint for the armature and thus controls
the pickup value of the switch.
Indicating Contactor Switch Unit (ICS)
(When Supplied)
The de indicating contactor switch is a small
clapper type device. A magnetic armature, to which
leaf-spring mounted contacts are attached, is attrac­
ted to the magnetic core upon energizing of the
switch. When the switch closes, the moving contacts
bridge two stationary contacts, completing the trip
circuit. Also during this operation two fingers on
the armature deflect a spring located on the front of
the switch, allowing the operation indicator target
to drop.
The front spring, in addition to holding the target,
provides restraint for the armature and thus controls
the pickup value of the switch.
C HA R A CTERIS TICS
The relay operates in 4 milliseconds for an energy
10
input of watts .
The relay is adjusted to have a pickup value less
than 80% of rating, but not less than
typical battery equalizing charge voltage. i.e. mini­
mum pickup is greater than
TABLE I
28
volts for 48 volt rating
70 125
volts for volt rating
250
140 volts for volt rating
EF F EC T IV E MARCH 1976
I L 41-759.3
. .
MAINTENANCE
•
(When Supplied)
of the switch.
50%
of the