Westinghouse HQS Installation, Operation & Maintenance Instructions Manual

INSTALLA TION
INSTRUCTIONS
TYPE HQS PHASE SELECTOR RELAY FOR
SELECTIVE-POLE CARRIER RELAYING
CAUTION
B efore
putting · r elays into service,
remove all blocking
serted for the purpose of securing the parts
during shipment, make
parts operate freely, inspect the contacts to
see that they are clean and close properly,
and operate the relay to check the settings
and electrical connections.
APPLICATION
The type HQS relay operates on negative and
zero sequence currents to select the faulted
phase when single
a
occurs on the protected
The zero sequence current is obtained from the
neutral of the line current transformers, and
the negative sequence current from an external
three-phase filter supplied with the relay.
CONSTRUCTION AND OPERATION
The type HQS relay consists of three phase
selector elements, three contactor switches,
and three operation indicators mourited in the
standard case of Figure
three-phase negative,
mounted in the case of Figure
at· i on of this relay in the carrier scheme is
described in I.L. 41-600.2.
Phase Selector
The phase selector element is similar to the
element as used in the type HZ
H directional
and HRK-P relays. The primary of a small cur­
rent transformer receives the
_component of line current which causes a large
current to flow in a one-turn movable aluminum
secondary. Two other
mounted on either side of a magnetic frame and
these coils receive the negative sequence com­
ponent of line current from
SUPERSEDES I.L. 41-610.1 B
which may have been in­
sure that all moving
phase-to-ground fault
transmission line.
4. The external
sequence filter is
3. The oper­
zero sequence
coils are
current
an external
•
OPERATIO N
filter. These zero
elements are assembled at right angle to each
other with the one-turn loop in the air gaps
of the negative sequence current coil
path. The interaction of the two fluxes pro­
duces torque and rotates the loop in a direc­
tion depending on the relative instantaneous
direction of current flow in the two coils.
An
Isolantite arm
loop and supports a rectangular silver contact
which bridges two stationary contacts mounted
on either side of the loop.
contacts are
silver conical surfaces mounted
on the lower end of
s prings. The contact separation is adjustable
by a small screw
rigid stationary contact supporting arm.
of these supporting
each of the four stationary contacts.
screw on the lower end of this arm provides
the contact follow adjustment.
screws on the movement
negative sequence coil iron limit the movement
of the loop. There are three of these phase
selector elements,
phases and designated S
A, B , and C
respectively.
and 0 indicate
the negative and zero sequence
coils.
Contactor Switch
The d-e. contactor switch in the relay is a
small solenoid type
plunger with a silver
lower end moves in the core of the solenoid.
As the plunger travels
bridges three silver stationary contacts.
coil is in series with the main contacts of
the relay and with
breaker. When the
coil becomes energized and closes the switch
EFFECTIVE FEBRUARY 1949
J.L. 41-610. 1 c
•
MAINTENA NCE
and negative sequence
flux
extends from the moving
The stationary
vertically
hanging
near the upper end of the
One
arms hangs parallel to
The set
Tw o additional
frame beneath the
one for each of the three
and s0 for phases
, S
B
A
The sub numbers
switch. A cylindrical
disc mounted on its
upward, the disc
The
the trip coil of the
relay contacts close, the
2