Westinghouse CV-1 Installation, Operation And Maintenance Instructions

Before putting relays into 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
close properly, and operate the relay to check the
settings and electrical connections.
The Type CV Relays are single-phase induction­
disc type relays operating either on under or over­
voltage or both. These relays are applied as a volt­
age fault detector operating in conjunction with
' . .-?'
( other protective relays. The relays are also used as
timing devices for various automatic operations.
This instruction leaflet applies to the following
types of relays:
CV- 1 Long Time Undervoltage Relay
CV-2 Short Time Undervoltage Relay
CV -4 Long Time Overvoltage Relay
CV-5 Short Time Overvoltage Relay
CV-6 Long Time Over or Undervoltage Relay
CV-7 Short Time Over or Undervoltage Relay
CV-8 Low Voltage Pickup Overvoltage Relay
CONSTRUCTION AND OPERATION
The Types CV- 1, CV-2, CV-4, CV-5, CV-6, and
CV-7 Relays consist of a voltage unit and an indi­
cating contactor switch (ICS). The principal com­
ponent parts of the relay and their location are
shown in Figs. l, 2, and
All possible contingencies which may arise during installation, operation, or maintenance, and all
details and variations of this equipment do not purport to be co Fe red by these instructions. If further
information is desired by purchaser regarding his particular installation, operation or maintenance of
his equipment, the local Westinghouse Electric Corporation representatire should be contacted.
SUPERSEDES I.L. 41-201L DATED SEPTEMBER 1982
INSTALLATION
TYPE CV VOLTAGE RELAY
CAUTION
APPLICATION
CONTENTS
3.
• •
The Type CV-8 Relay in addition to the above
components also has a capacitor which is series
tuned with the main coil of th e electromagnet.
This tuned circuit offers a low impedance to
fundamental current and a high impedance to
third harmonic currents. Hence, the relay has a
low pickup value for fundamental voltage and a
much higher value of pickup for third harmonic
voltage. At rated voltage the electromagnet is
saturated causing the circuit to be detuned. The
impedance of the circuit is increased and limits
the fundamental current to a safe value.
A. Voltage Unit (CV)
The overvoltage unit operates on the induction­
disc principle. A main tapped coil located on the .
center leg of an "E" type laminated structure pro­
duces a flux which divides and returns through
the outer legs. A shading coil causes the flux
through the left leg (front view) to lag the main
pole flux. The out-of-phase fluxes thus produced
in the air gap causes a contact closing torque.
The undervoltage unit operates on the same
principle as the overvoltage unit except the shad­
ing coil is on the right leg (front view). This causes
the out-of-phase fluxes to produce a contact
opening torque.
B. Indicating Contactor Switch (ICS)
The indicating contactor switch is a small d-e
operated clapper type device. A magnetic arma­
ture, to which leaf-spring mounted contacts are
attached, is attracted to the magnetic core upon
energization of the switch. When the switch
closes, the moving contacts bridge two stationary
contacts, completing the trip circuit. Also, during
Wes tinghouse I.L. 41-201M
MAINTENANCE
EFFECTIVE JANUARY 1984