Westinghouse COQ Series Installation Operation & Maintenance

INSTAL LATIO N
INS TRU CTI ON S
NEGATIVE SEQUENCE GENERATOR RELAY
Before putting
CAUTION
into service, remove all
have been inserted for the purpose of securing
the parts during shipment.
moving parts operate freely.
tacts to see that they are clean and can close
properly. Operate the
settings and electrical connections.
APPLICATION
A COQ relay operates to disconnect a genera-
tor from a faulted
sequence currents can damage the machine.
CONSTRUCTION AND OPERATION
The type COQ relay consists
disc type overcurrent
s�itch, an operation indicator, and a negative
sequence current filter.
OVERCURRENT ELEMENT
This is an induction-disc
operated by negative
supplied to an electromagnet
the relay. A voltage
secondary coil of this electromagnet by trans­
former action of the
are located on the center leg of the electro­
magnet. Current flow is from the
coil to coils on the outer legs
tromagnet. The reaction between the outer leg
coil fluxes and the main coil flux creates an
operating torque on a spiral
disc mounted on a vertical shaft.
The vertical shaft is
ment frame by a pin and end stone type bearing
on the lower end and a pin
on the upper end. Both shaft bearings as well
SUPERSEDES I. L. 41-277A
4<])enotes changed from superseded issue.
TYPE COQ
protective relays
blocking which may
Make sure that all
I nspect the con­
relay to check the
line before negative
of an induction
element, a contactor
type element
sequence quantities
in the rear of
is induced in the
main coil. Both coils
secondary
of the elec­
shaped aluminum
supported to the ele­
and olive bearing
OPERA TION
•
as their 2djustable pins are removable.
screw and nylon plug
position, and a sho�lder nut
locks the top pin in position.
Attached to an
disc shaft is a rigid
silver hemisphere.
and silver hemisphere
contact assembly which
trical circuit. This circuit is completed by
a spiral spring with
rigid arm and the
slotted spring adjuster which
to the element frame.
The stationary contact assembly
a silver contact attached to the
the leaf spring. This spring is fastened to a
Micarta block mounted on the element frame.
small set screw permits the adjustment of con­
tact follow.
Contactor Switch
This switch is a
conneqted in series with
the relay and the trip coil of
When the relay contacts
coil becomes energized and moves a cylindrical
plunger upward.
the plunger's lower end,
contacts which are in parallel
contacts. The main
lieved of the duty of carrying
rents. These three
until the trip circuit is opened by an auxili­
ary switch on the breaker.
Operation I ndicator
The operation indicator is a small solenoid
I.L. 41-2778
MAINTENANCE
•
A set
locks the bottom pin in
of the time dial
insulated section of
arm holding small
a
This combination of arm
comprises the moving
is part of an elec­
one end soldered to
other end fastened to
in turn fastens
consists of
free end of
small d-e solenoid type
the main contacts of
a breaker.
close, the solenoid
A silver disc is mounted on
and it bridges three
with the main
contacts are thereby re­
tripping cur­
contacts remain closed
EFFECTIVE APRIL 1957
the
the
a
A