11
Figure 4: Vacuum circuit breaker magnetic-actuator operator module
Item
Description
16.0
Pole support channels
16.1
Post insulator
20.0
Fixed-end pole head
27.0
Fixed-end connection pad
28.0
Strut
29.0
Moving-end connection pad
30.0
Vacuum interrupter
40.0
Moving-end pole head
48.0
Insulating coupler
49.0
Contact pressure spring
60.0
Mechanism housing
49.0
48.0
40.0
29.0
28.0
30.0
16.1
16.1
20.0
27.0
16.0
16.0
Figure 5: Vacuum interrupter cutaway view
A
Item
Description
A
Fixed-contact current connection
B
Ceramic insulator
C
Arc shield
D
Fixed contact
E
Moving contact
F
Metal bellows
G
Guide
H
Moving-contact current connection
B
C
D
E
F
B
G
H
60.0
Introduction
The type 3AH35-MA vacuum circuit breaker
magnetic-actuator operator is intended for
stationary applications, such as the type
SDV7-MA outdoor distribution circuit breaker.
The type 3AH35-MA circuit breaker magnetic
actuator conforms to the requirements of
ANSI/IEEE standards, including C37.04,
C37.06, C37.09 and C37.010.
The circuit breaker includes three vacuum
interrupters, a magnetic-actuator operating
mechanism, necessary electrical controls and
an operator housing. In a typical installation,
insulating barriers may be located between
the vacuum interrupters.
This section describes the operation of each
major subassembly as an aid in the operation,
maintenance and repair of the circuit breaker.
Vacuum interrupters
The operating principle of the vacuum
interrupter is simple. Figure 5: Vacuum
interrupter cutaway view is a section view of
a typical vacuum interrupter. The entire
assembly is sealed after a vacuum is
established. The vacuum interrupter
stationary contact is connected to the fixed-
end pole head (20.0) of the circuit breaker.
