Westinghouse
I.L. 41-103G
INSTALL A Tl 0 N
•
OPERATION
•
MAINTENANCE
INSTRUCTIONS
TYPE CO CIRCUIT OPENING
OVERCURRENT RELAY
CAUTION
Before putting relays into service, remove all
blocking which may have been inserted for the pur
pose of securing the parts during shipment, make
sure that all moving parts operate fr
�
ely, inspect the
contacts to see that they are clean and close properly,
and operate the relay to check the settings and
electrical connections.
A P P L ICAT IOH
These induction overcurrent relays are used to
disconnect circuits or apparatus when the current in
them exceeds a given value . When no suitable
station battery is available, the circuit opening
type relay in conjunction with a-c series trip coil is
used to trip the circuit breaker.
COHT EHTS
This instruction leaflet applies to the following
types of circuit opening relays:
Type co-2 Short Time Relay
C0-5 Long Time Relay
C0-6 Definite Minimum Time Relay
C0-7 Moderately Inverse Time Relay
C0-8 Inverse Time Relay
C0-9 Very Inverse Time Relay
C0-11 Extremely Inverse Time Relay
COHSTRUCTIOH AHD OP ERATIOH
The type CO relays consist of an overcurrent
unit (CO), a de-ion contactor switch (CS), an opera
tion indicator (01) and an indicating instantaneous
trip
(liT)
when required.
ELECTROMAGNE T
The electromagnets for the types CQ-5, C0- 6 ,
C0-7, C0-8 and C0-9 relays have a main tapped coil
located on the center leg of an "E" type laminated
structure that produces a flux which divides and re
turns through the outer legs. A shading coil causes
the flux through the left leg to lag the main pole
SUPERSEDES I.L. 41-103F, dated June 1968
*Denotes change from superseded Issue.
flux.
The out-of-phase fluxes thus produced in the
air gap cause a contact closing torque.
The electromagnets for the types C0-2 and
C0-1 1 relays have a main coil consisting of a tapped
primary winding and a secondary winding.
Two
identical coils on the outer legs of the lamination
structure are connected to the main coil secondary
in a manner so that the combination of all the fluxes
produced by the electromagnet result in out-of-phase
fluxes in the air gap.
The out-of-phase air gap
fluxes produced cause a contact closing torque.
DE-ION CONTACTOR SWITCH (CS)
This switch is a small a-c solenoid switch
whose coil is energized from a small transformer
connected in the main current circuit. A cylindrical
plunger operates a spring leaf arm with a silver
contact surface on one end and rigidly fixed to the
frame at the other end.
The overcurrent unit contacts are in the con
tactor switch coil circuit and w�n they close , the
solenoid plunger moves upward to open the de-ion
contacts which normally short circuit the trip coil.
These contacts are able to transfer the heavy current
due to a short circuit and permit this current to ener
gize the breaker trip coil.
OPERATION INDICATOR (01)
The operation indicator is a small clapper type
device .
A magnetic armature is attracted to the
All
possible contingencies which may arise during
installation, operation, or maintenance, and all
details and variations of this equipment do not
purport to be covered by these instructions. If
further information is desired by purchaser re
garding his particular installation, operation or
maintenance of his equipment, the local West
inghouse Electric Corporation representative
should be contacted.
EFFECTIVE JUNE 1976
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