ABB AMVAC Technical Manual page 10

AMVAC. Circuit breaker specifier's guide.
General
The Circuit breaker shall be an ABB AMVAC or approved equal, three-pole, drawout (or
stationary) type, electrically operated with stored energy magnetic actuator operating
mechanism. The circuit breaker is intended for use as a general purpose device in
accordance with the latest revisions of the following ANSI standards applying
to 5, 7.5, 15, or 27 kV applications: ANSI C37.04, C37.06, and C37.09. The
circuit breaker shall also conform to the general purpose capacitor switch-
ing ratings referenced in the ANSI standards.
Option: Definite purpose capacitor switching ratings are optionally offered
for single and back-to-back applications. Details of these applications are
required at the time of quotation to insure conformance to specific appli-
cations.
Drawout Circuit Breaker Racking System and Interlocks
The circuit breaker shall be inserted and withdrawn by means of a breaker
mounted racking system, which can be operated with the compartment
door open or closed. The racking system shall provide smooth consis-
tent racking, and shall secure the breaker from both sides of the cell
in all racking positions. During racking, the breaker shall automati-
cally open and close cell-mounted safety shutters to cover station-
ary primary contacts when the breaker is not in the "Connected"
position.
The racking system shall have three distinct positions. In
addition to the withdrawn position (free movement):
"Disconnected" (both primary and secondary con-
tacts disengaged), "Test" (secondary contacts
engaged, primary contacts disconnected, and shut-
ter closed), and "Connected" (Shutter open, pri-
mary and secondary contacts engaged). Positive
stops shall be provided for all three positions, with
deliberate operator intervention required to enable con-
tinued insertion or withdrawal of the circuit breaker from any
position.
The racking system and all moving parts of the breaker-cell interface, including the secondary disconnects, shutter actuator and ground
contact, shall be capable of 500 complete rack-in/rack-out operations without maintenance.
It shall not be possible to insert or withdraw a closed breaker, and the breaker shall not be allowed to close within a cell unless it is in the
"Connected", "Test", or "Disconnected" position. Electrical and mechanical blocking means shall be employed to preclude breaker
contact closure in any position other than "Connected", "Test", or "Disconnected". The stored energy capacitors shall be automatically
discharged in the "Disconnected" position prior to removing the circuit breaker from the circuit breaker compartment.
Controls
Opening and closing speed shall be independent of the operator or the control voltage within the rated control voltage range. Circuit
breaker charge, close, and trip circuits shall be electrically separated, and control voltage for each circuit shall be independently specified
from the full range of ANSI preferred control voltages. Provisions shall be provided for manually opening the circuit breaker. These pro-
visions shall be installed and easily accessible at the front of the breaker.
All control components shall be front-accessible for quick inspection after easy removal of the circuit breaker front cover. Mechanism
operated cell switches shall not be allowed; the circuit breaker shall include eight on-board auxiliary contacts (four normally open "a" and
four normally closed "b") for customer use, wired through the secondary disconnect. All breaker-mounted contacts shall operate in both
the "Connected" and "Test" positions.
Option: Nine additional contacts (for a total of nine normally open "a" and eight normally closed "b") shall be installed on the circuit
breaker and wired through the secondary disconnect, for a total of 17 on-board contacts.
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