ABB AMVAC Technical Manual - Amvac

4

AMVAC

Summary of benefits:

• Simple mechanical operation

• Fewer than 10 moving parts

• Manual opening capability

• High reliability

Manual opening mechanism

Magnetic actuator

Electronic controller

Auxiliary contacts

Electrical energy storage

Sensor for switching position

detection

The magnetic actuator,

encapsulated vacuum interrupter

pole assemblies, electronic 

controller, capacitors, and push

button/capacitor discharge 

assembly are the key components

for this next generation product.

The magnetic actuator has a 

magnetic frame assembly, two 

identical operating coils, two rare

earth magnets, and a single moving

armature. Instead of mechanical

assemblies for armature position

sensing, proximity sensors detect

armature position for the 

electronic controller. The rare earth

magnets are especially encapsulated

to eliminate the corrosion normally

associated with this type of

magnet. Evaluation confirms that

these permanent magnets will

retain 99% of their flux density for

over 100 years.

Similar evaluations find that the

capacitors used for stored energy

have a lifetime up to 20 years.

These special capacitors charge in

as little as seven seconds after 

control power is available and are

periodically "topped off" by the

electronic controller as needed.

Covers over the capacitor terminals

prevent accidental contact. The

capacitors are discharged by a

unique discharge assembly when

the circuit breaker is moved to the

"Disconnect" position and the

racking truck handles are moved

inward to unlock the circuit break-

er from the breaker compartment.

The AMVAC circuit breaker is

designed to provide many years of

trouble free service for the end

user.