ABB AMVAC Technical Manual page 11

On drawout circuit breakers, a self-aligning,
fully automatic secondary coupling system
shall be used to connect and disconnect all
control wiring during circuit breaker insertion
and withdrawal. The secondary disconnect
shall require no manual intervention to attain
proper position when the breaker is racked to
the "Connected", "Test", or "Disconnected"
positions. Secondary contacts shall use a
corrosion inhibiting contact finish. 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 break-
er-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.
The circuit breaker shall have a flag to indicate open or closed position. An indicating light will illuminate when the stored energy system
has sufficient energy for circuit breaker change of state. During the capacitor charging function, the indicator blinks green illumination
until full capacitor charge when solid green illumination is provided. Capacitors shall store sufficient energy to provide and open-close-
open function even after loss of control power. Capacitors shall hold their charge for up to 200 seconds after loss of control power. A
loss of control power trip function shall be user selectable.
The circuit breaker shall have a five-digit, non-resetting operation counter clearly visible from the front of the breaker. The operation
counter shall advance when the breaker opens. An electronic controller shall be provided for controlling capacitor charging, switching
capacitor energy to the closing or opening coils, and providing the anti-pumping feature. The electronic controller shall also incorporate
undervoltage and remote monitoring functions. Electronic controllers shall be universal AC/DC devices allowing either 24 - 60 VAC or
VDC or 110 - 250 VAC or VDC control power flexibility. All control components shall be front-accessible for quick inspection after
easy removal of the circuit breaker front cover. Proximity sensors shall be used to sense magnetic actuator armature position.
Option: Electronic controller shall have (instantaneous) (time delay) undervoltage function that shall cause the circuit breaker to open
when the control power falls to a value which is 30-60% of nominal voltage.
Option: Electronic controller shall be equipped with Close Blocker and Close Locker features to electronically prevent local or remote
actuation of close function.
Current Path
Each primary lead assembly shall consist of a vacuum interrupter completely embedded in an epoxy resin casting. The epoxy casting
shall encapsulate not only the vacuum interrupter, but also the upper and lower current carrying parts and brush-type current transfer
assembly. The epoxy casting shall limit access to any moving parts, protecting them from dirt and debris. Epoxy encapsulation shall be
used on all 630, 1200, or 2000 ampere circuit breakers. Connecting directly to embedded pole pads, silver-plated copper upper and lower
leads shall use tulip-type self-aligning primary disconnects. A dedicated ground contact shall be provided to engage the stationary ground
contact in the circuit breaker compartment to ground the circuit breaker in all positions from "Disconnected" through "Connected".
Maintenance and Handling
The magnetic actuator mechanism shall be front-accessible. No routine lubrication of the magnetic actuator shall be required. Routine
inspections shall be performed with the breaker in the upright position. Interrupters shall have a contact wear indication for evaluation
by contact measurement tools. Circuit breakers shall have self-contained wheels designed for easy insertion, removal and transport on
flat indoor surfaces.
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