Siemens 3AH35-MA User Manual
www.usa.siemens.com/sdv7
Instruction manual
Type 3AH35-MA vacuum circuit breaker
magnetic-actuator operator module
Installation operation maintenance E50001-F710-K378-X-4A00
Answers for infrastructure.
Hazardous voltages and stored energy.
Will cause death, serious injury or property damage.
Even if the circuit breaker and control circuits have been de-energized
for a long time, the power supply capacitors will maintain significant
stored energy. Always discharge the capacitors before maintenance.
Always de-energize and ground the equipment before maintenance.
Read and understand this instruction manual before using equipment.
Maintenance should be performed only by qualified personnel. The use
of unauthorized parts in the repair of the equipment or tampering by
unqualified personnel will result in dangerous conditions which will
cause death, severe injury or equipment damage. Follow all safety
instructions contained herein..
Stored energy and high speed moving parts.
Will result in serious injury. Fingers can be crushed by the magnetic
actuator.
Do not remove guard panel. Do not operate circuit breaker if guard
panel removed.
Important
The information contained herein is general in nature and not
intended for specific application purposes. It does not relieve the
user of responsibility to use sound practices in application,
installation, operation and maintenance of the equipment
purchased. Siemens reserves the right to make changes in the
specifications shown herein or to make improvements at any
time without notice or obligation. Should a conflict arise
between the general information contained in this publication
and the contents of drawings or supplementary material or
both, the latter shall take precedence.
Qualified person
For the purpose of this manual a qualified person is one who is
familiar with the installation, construction or operation of the
equipment and the hazards involved. In addition, this person has
the following qualifications:
Is trained and authorized to
de-energize, clear, ground and tag circuits and equipment in
accordance with established safety procedures.
Is trained in the proper care and use of protective
equipment, such as: rubber gloves, hard hat, safety glasses or
face shields, flash clothing, etc., in accordance with
established safety practices.
Further, a qualified person shall also be familiar with the proper use
of special precautionary techniques, personal protective equipment,
insulation and shielding materials, and insulated tools and test
equipment. Such persons are permitted to work within limited
approach of exposed live parts operative at 50 volts or more, and
shall, at a minimum, be additionally trained in all of the following:
The skills and techniques necessary to distinguish exposed
energized parts from other parts of electric equipment
The skills and techniques necessary to determine the nominal
voltage of exposed live parts
The approach distances specified in NFPA 70E and the
corresponding voltages to which the qualified person will be
exposed
The decision-making process necessary to determine the degree
and extent of the hazard and the personal protective equipment
and job planning necessary to perform the task safely.
Is trained in rendering first aid.
Note:
These instructions do not purport to cover all
details or variations in equipment, nor to
provide for every possible contingency to be
met in connection with installation, operation
or maintenance. Should further information be
desired or should particular problems arise
that are not covered sufficiently for the
purchaser’s purposes, the matter should be
referred to the local sales office.
Table of contents
Introduction 04 – 05
Installation checks and functional tests 06 – 09
Vacuum interrupter/operator 10 – 25
Maintenance 26 – 40
Overhaul 41 – 47
The contents of this instruction manual shall
not become part of or modify any prior or
existing agreement, commitment or
relationship. The sales contract contains the
entire obligation of Siemens Industry, Inc. The
warranty contained in the contract between
the parties is the sole warranty of Siemens
Industry, Inc. Any statements contained herein
do not create new warranties or modify the
existing warranty.
Technical data and troubleshooting 48 – 51
Introduction
Hazardous voltages and stored energy.
Will cause death, serious injury or property damage.
Even if the circuit breaker and control circuits have been de-energized
for a long time, the power supply capacitors will maintain significant
stored energy. Always discharge the capacitors before maintenance.
Always de-energize and ground the equipment before maintenance.
Read and understand this instruction manual before using equipment.
Maintenance should be performed only by qualified personnel. The use
of unauthorized parts in the repair of the equipment or tampering by
unqualified personnel will result in dangerous conditions which will
cause death, severe injury or equipment damage. Follow all safety
instructions contained herein..
Stored energy and high speed moving parts.
Will result in serious injury. Fingers can be crushed by the magnetic
actuator.
Do not remove guard panel. Do not operate circuit breaker if guard
panel removed.
4
Introduction
The type 3AH35-MA vacuum circuit breaker
magnetic actuator module is designed to
meet all applicable ANSI, NEMA and IEEE
standards. Successful application and
operation of this equipment depends as
much upon proper installation and
maintenance by the user as it does upon the
proper design and fabrication by Siemens.
The purpose of this instruction manual is to
assist the user in developing safe and
efficient procedures for the installation,
maintenance and use of the equipment.
Contact the nearest Siemens representative
if any additional information is desired.
Signal words
The signal words “danger,” “warning” and
“caution” used in this manual indicate the
degree of hazard that may be encountered by
the user. These words are defined as:
Danger - Indicates an imminently hazardous
situation that, if not avoided, will result in
death or serious injury.
Warning - Indicates a potentially hazardous
situation that, if not avoided, could result in
death or serious injury.
Caution - Indicates a potentially hazardous
situation that, if not avoided, may result in
minor or moderate injury.
Notice - Indicates a potentially hazardous
situation that, if not avoided, may result in
property damage.
Hazardous procedures
In addition to other procedures described in
this instruction manual as dangerous, user
personnel must adhere to the following:
1. Always work only on a de-energized
circuit breaker. The circuit breaker should
be isolated, grounded and have all control
power removed before performing any
tests, maintenance or repair.
2. Before working on the circuit breaker
make sure the capacitors (106.2) are fully
discharged (refer to Figure 2: Operator
controls and discharging capacitors on
page 7). Verify that the CLOSE/OPEN
indicator (58.0) is in the OPEN position.
Discharge the capacitors (106.2) by
unplugging the connector (105.2) on the
controller board (105.0). The red LED
(106.4) on each of the capacitor boards
(106.1) indicate the state of the charge
on the capacitors (106.2). When the
capacitors (106.2) are discharging, the
LEDs are flashing. This indicates
hazardous voltage. When the LEDs stop
flashing, the capacitors are discharged to
a low voltage.
3. Always let an interlock device or safety
mechanism perform its function without
forcing or defeating the device..
Field service operation and warranty
issues
Siemens can provide competent, well-trained
field service representatives to provide
technical guidance and advisory assistance
for the installation, overhaul, repair and
maintenance of Siemens equipment,
processes and systems. Contact regional
service centers, sales offices or the factory for
details, or telephone Siemens field service at
+1 (800) 347-6659 or +1 (919) 365-2200
outside the U.S.
For medium voltage customer service issues,
contact Siemens at +1 (800) 347-6659 or +1
(919) 365-2200 outside the U.S.
5
Installation checks
and functional tests
Figure 1: Type 3AH35-MA 27.6 kV
25 kA vacuum circuit breaker
magnetic-actuator operator module
Introduction
This section provides a description of the
inspections, checks and tests to be performed
on the circuit breaker magnetic actuator
module only.
The inspections and checks in this section are
to be performed with the circuit breaker
disconnected and isolated from primary
(high-voltage) power sources.
Inspections, checks and tests
without control power
De-energizing control power
To de-energize control power in the outdoor
circuit breaker, open the control power
disconnect device in the relay and control
compartment.
The control power disconnect device is
normally a fused knife switch. Opening the
knife switch de-energizes control power to
the circuit breaker operating mechanism. In
some outdoor circuit breakers, a molded-case
circuit breaker or pullout-type fuse holder
may be used in lieu of the fused knife switch.
Opening the fused knife switch, or moldedcase circuit breaker, or removing the pullouttype fuse holder accomplishes the desired
result: control power is disconnected.
If any maintenance is to be performed,
discharge the capacitors.
Fast discharge of capacitors
After control power has been removed,
discharge stored energy from the capacitors
(refer to Figure 2: Operator controls and
discharging capacitors on page 7).
1. Press red Open pushbutton (54.0).
2. Remove the mechanism housing cover
sheet (60.1).
3. The green LED on the power supply
(104.0 in Figure 2: Operator controls and
discharging capacitors on page 7) should
not be illuminated. If the green LED is on,
open the control power disconnect device
in the relay and control compartment.
4. Discharge the capacitors (106.2) by
unplugging the connector (105.2) from
the controller board (105.0). Do not
unplug connector (106.3) from the
capacitor boards, or damage to the
capacitor board or the controller board
may occur. The red LED (106.4) on each
of the capacitor boards (106.1) indicates
the state of charge of the capacitors
(106.2). When the capacitors (106.2) are
discharging, the red LEDs are flashing.
This indicates a hazardous voltage. When
the LEDs stop flashing, the capacitors
(106.2) are discharged to a low voltage.
As-found and vacuum-integrity check tests
Perform and record the results of both the asfound insulation test and the vacuumintegrity check (dielectric) test. Procedures for
these tests are described in the Maintenance
section of this instruction manual beginning
on page 26.
6
105.1
54.0
53.0
60.1
59.0
58.0
60.0
104.0
105.0
Identification Description
53.0 Close pushbutton (black)
54.0 Open pushbutton (red)
58.0 CLOSED/OPEN indicator
59.0 Operations counter
60.0 Mechanism housing
60.1 Mechanism housing cover
104.0 Power supply (green LED shown circled)
105.0 Controller board
105.1
105.2 Connector for capacitors
106.1
106.2 Capacitor
106.3 Connector (for each capacitor board)
106.4 Red LED capacitor discharge state
Light-emitting diodes (LEDs)
(red, yellow, green)
Capacitor board
(two or three depending upon rating)
105.2
105.2
106.1
106.1
105.0
106.2
106.3
106.4
Figure 2: Operator controls and discharging capacitors
7
Hazardous voltages and stored energy.
Will cause death, serious injury or property damage.
Even if the circuit breaker and control circuits have been de-energized
for a long time, the power supply capacitors will maintain significant
stored energy. Always discharge the capacitors before maintenance.
Always de-energize and ground the equipment before maintenance.
Read and understand this instruction manual before using equipment.
Maintenance should be performed only by qualified personnel. The use
of unauthorized parts in the repair of the equipment or tampering by
unqualified personnel will result in dangerous conditions which will
cause death, severe injury or equipment damage. Follow all safety
instructions contained herein..
Stored energy and high speed moving parts.
Will result in serious injury. Fingers can be crushed by the magnetic
actuator.
Do not remove guard panel. Do not operate circuit breaker if guard
panel removed.
8
Automatic capacitor charging
When control power is energized, the
controller board (105.0) executes a self-test
of the capacitors (106.2) and checks the
status of the capacitors (106.2). This self-test
runs automatically and regularly. The result of
the self-test is stored in the memory of the
controller board (105.0).
Capacitor charging check
The capacitor charging system of the circuit
breaker must be checked. Control power is
required for capacitor charging.
Note: A temporary source of control power
and test leads may be required if the control
power source has not been connected to the
circuit breaker. Refer to the specific wiring
information and rating label for your circuit
breaker to determine the voltage required
and the terminal points where the control
voltage signal should be applied. When
control power is connected to the circuit
breaker, the capacitors should automatically
charge.
1. Close the control power disconnect device
in the relay and control compartment to
energize the circuit breaker control circuit.
If not previously charged, the capacitors
should charge automatically.
2. Use the Close and Open pushbuttons on
the circuit breaker operating mechanism
(refer to Figure 3: Operator panel controls
on page 10) to first close, and then open
the circuit breaker contacts. Verify contact
positions visually by observing the OPEN/
CLOSED indicator on the circuit breaker.
When the capacitors are fully discharged
and control power is applied, the yellow
LED lights after approximately 25
seconds. The yellow LED turns off about
5-10 seconds later and the green LED
lights.
3. In step 2, when the Close pushbutton was
pressed, the circuit breaker should have
closed, and the capacitors should have
recharged automatically. The meaning of
the LEDs (105.1) on the controller board:
4. Perform the magnetic actuator-discharge
check.
a) Initial status: circuit breaker open.
b) Press red Open pushbutton (54.0).
c) Press black Close pushbutton (53.0).
d) Verify main contact status indicator
shows CLOSED.
e) Press red Open pushbutton (54.0)
again.
f) Verify main contact status indicator
shows OPEN.
5. De-energize the control power by opening
the control power disconnect device in
the relay and control compartment.
Remove the mechanism housing cover
sheet (60.1). Do not unplug connector
(106.3) from the capacitor boards, or
damage to the capacitor board or the
controller board may occur. Fast discharge
the capacitors (106.2) by unplugging the
connector (105.2) on the capacitor
controller board (105.0). During fast
discharge of the capacitors, a red LED on
each capacitor board will flash, indicating
that discharge is in process. The process is
complete when the red LED stops
blinking.
6. After the fast-discharge process, plug in
the connector (105.2) to the controller
board (105.0).
Final mechanical inspections without
control power
1. Make a final mechanical inspection of the
circuit breaker. Verify the contacts are in
the OPEN position.
2. Check visually that the connectors (106.3)
for each capacitor board are firmly
connected. Do not disconnect these
connections.
3. Reinstall the mechanism housing cover
sheet (60.1).
4. Check for loose hardware.
a) Green LED indicates ready (energy
sufficient for OPEN-CLOSE-OPEN cycle).
b) Yellow LED indicates open possible
(energy sufficient for OPEN operation).
c) Red LED indicates error (energy not
sufficient for operation).
9
Identification Description
53.0
54.0
58.0
59.0 Operations counter
105.1
Close pushbutton
(black)
Open pushbutton
(red)
CLOSED/OPEN
indicator
LEDs:
Red LED indicates
error (energy not
sufficient for
operation).
Yellow LED indicates
open possible
(energy sufficient for
OPEN position).
Green LED indicates
ready (energy
sufficient for OPENCLOSE-OPEN cycle).
Vacuum interrupter/
operator
59.0
58.0
54.0
105.0
53.0
Figure 3: Operator panel controls
10
27.0
28.0
29.0
Identification 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
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.
20.0
A
G
40.0
30.0
16.116.1
48.0
16.0
Figure 4: Vacuum circuit breaker magnetic-actuator operator module
Identification Description
B
C
D
E
B
F
H
16.0
49.0
60.0
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
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 fixedend pole head (20.0) of the circuit breaker.
Figure 5: Vacuum interrupter cutaway view
11
48.6
49.0
63.3
Identification Description
48.6 Angled lever
49.0 Contact pressure spring
63.1 Lever - phase C
63.3 Lever - phase A
63.5 Lever - phase B
Figure 6: Vacuum circuit breaker magnetic-actuator operator module
49.0
63.5
The vacuum interrupter movable contact is
connected to the flexible shunt (29.1)
associated with the other pole head and to
the driving mechanism of the circuit breaker.
The metal bellows provide a secure seal
around the movable contact, preventing loss
of vacuum while permitting motion of the
movable contact along the axis of the
vacuum interrupter.
When the two contacts separate, an arc is
initiated that continues conduction up to the
following current zero. At current zero, the
arc extinguishes and any conductive metal
vapor that has been created by and supported
the arc condenses on the contacts and on the
surrounding arc shield. Contact materials and
configuration are optimized to achieve arc
motion and to minimize switching
disturbances.
63.1
49.0
Primary connections
Figure 4: Vacuum circuit breaker magneticactuator operator module on page 11
illustrates the pad provision to accept the
primary connections. Each circuit breaker has
three connection pads at the fixed end of the
vacuum interrupter, and three connection
pads on the flexible connectors that are
associated with the movable contact of the
vacuum interrupter. Interconnecting bus in
the circuit breaker enclosure connects these
connection pads to the roof bushing
terminals. Bolting hardware is M12 x 1.75
grade 8. Torque M12 bolts to 52 ft-lb (70
Nm).
Phase barriers (if applicable)
For certain ratings, barriers of glass-polyester
insulating material are attached to the circuit
breaker and provide suitable electrical
insulation between the vacuum interrupter
and primary conductors and the enclosure.
Magnetic actuator operating mechanism
The energy needed for closing and tripping is
stored in two or three capacitor banks (106.0)
(depending on circuit breaker rating) charged
to approximately 160 V. The self-discharging
function is activated by removing the
connector (105.2) of the controller board
(105.0). Do not unplug connector (106.3)
from the capacitor boards, or damage to the
capacitor board or the controller board may
occur. The capacitors are charged
automatically when control power is applied.
From fully discharged condition, the
capacitors are fully charged in approximately
30-35 seconds.
The capacitor charge is monitored constantly
by the controller board (105.0). If the control
power source fails, the capacitors can initiate
one open operation initiated by the operatormounted pushbutton (54.0). This last
operation must be initiated within 300 s after
loss of control power supply. Within 300 s
after loss of operator control power, the
circuit breaker can perform one open
operation initiated by a remote command if
the remote command is from a wet
(powered) contact.
The green LED, which indicates that energy is
sufficient for an OPEN-CLOSE-OPEN operation
is illuminated as long as the voltage of the
capacitors is greater or equal to 150 V.
12
Vacuum interrupter/operator module
The vacuum interrupter/operator module
consists of the three poles, each with its
vacuum interrupter and primary insulators,
mounted above the common magnetic
actuator operating mechanism housing
(60.0). This module is shown in Figure 6:
Vacuum circuit breaker magnetic-actuator
operator module on page 12.
Construction
Each of the circuit breaker poles is fixed to the
pole support channel (16.0) by two cast-resin
insulators. The insulators also connect to the
fixed- and moving-end pole heads (40.0) that
in turn support the ends of the vacuum
interrupter. The pole supports are aluminum
castings or sheet steel (for 15.5 kV and
27.6 kV up to 25 kA). Refer to Figure 3:
Operator panel controls on page 10 and
Figure 4: Vacuum circuit breaker magneticactuator operator module on page 11, Figure
7: Pole assembly on page 14 and Figure 8:
Magnetic-actuator operating mechanism on
page 15.
The magnetic actuator mechanism and all the
control and actuating devices are installed in
the operator housing.
The CLOSE-OPEN indicator, Open pushbutton,
Close pushbutton, the LEDs on the controller
board and the operation counter are located
on the front of the mechanism housing.
The control connector for the control and
signalling cables is a multi-contact plug. The
mating control plug wiring connects to the
terminal blocks in the relay and control
compartment.
Circuit breaker pole (refer to Figure 7: Pole
assembly on page 14)
The vacuum interrupter is bolted to the fixedend pole head (20.0), which is rigidly
connected to the pole support channel (16.0)
by the post insulator (16.1). The moving
contact end of the vacuum interrupter is
stabilized against lateral forces by a centering
ring (28.1) on the moving-end pole head
(40.0). The external forces due to switching
operations and the contact pressure are
absorbed by the struts (28.0).
Current-path assembly (refer to Figure 7:
Pole assembly on page 14)
The current-path assembly consists of the
fixed-end pole head (20.0), the stationary
contact and the moving contact, plus a
flexible shunt (29.1) between the moving
contact terminal clamp (29.2) and the
moving-end connection pad (29.0).
Vacuum interrupter (refer to Figure 7: Pole
assembly on page 14)
The moving-contact motion is aligned and
stabilized by a guide bushing. The metal
bellows follows the travel of the contact and
seals the vacuum interrupter against the
surrounding atmosphere.
Switching operation
The sequence of actions involved in various
switching operations are described in this
section. Refer to Figure 7: Pole assembly on
page 14 and Figure 8: Magnetic-actuator
operating mechanism on page 15.
When a closing command is initiated, the
controller board (105.0) checks the circuit of
the magnetic actuator’s coil (101.3) for
integrity. After the integrity check has been
proven satisfactory, the capacitors (106.2)
power the magnetic actuator (101.0). This
process is monitored by the controller board
(105.0). The electrical current in the coil
(101.3) generates a magnetic field. An
attractive force causes the anchor (101.4)
moving upwards.
The coupling rod (62.8) moves upwards by
compressing the opening springs (64.0) by
means of the jack shaft (63.0). The contact
pressure springs (49.0) are compressed and
the insulating couplers (48.0) are moved
upwards. Through the angled levers (48.6)
the contacts in the vacuum interrupter (30.0)
are closed.
The forces that occur when the action of the
insulating coupler (48.0) is converted into the
action of the moving contact along the axis of
the vacuum interrupter are absorbed by the
guide link (48.9) that pivots on the movingend pole head and the eye bolt.
13
In the closed state, the necessary contact
pressure is maintained by the contact
pressure springs (49.0) and the atmospheric
pressure. The magnetic actuator maintains a
stable closed position without supplemental
energy input. The contact pressure spring
automatically compensates for arc erosion,
which is very small.
When a opening command is initiated, the
controller board (105.0) checks the circuit of
the magnetic actuator’s coil (101.3) for
integrity. After the integrity check has been
proven satisfactory, the capacitors (106.2)
power the magnetic actuator coil (101.3)
with a reverse current. This opposes the
attactive force between the magnetic
actuator (101.0) and the permanent magnet.
Due to the energy stored in the contact
pressure springs (49.0) and the opening
spring (64.0), the magnetic actuator’s anchor
(101.4) is pushed downwards. This opening
process is supported by the opening spring
(64.0). In the OPEN position the opening
spring assures that the ambient pressure does
not close the contacts in the vacuum
interrupters (30.0).
Operating mechanism
The operating mechanism is comprised of the
mechanical and electrical components
required to:
1. Charge the capacitors for providing
sufficient electrical energy to move the
magnetic actuator and close or open the
circuit breaker.
2. Mechanisms to release closing and
opening actions.
3. Means of transmitting force and motion
to each of the three vacuum interrupters.
4. Operate all these functions automatically
through the capacitors (106.2), the
controller board (105.0). auxiliary switch
3SV9 (68.0), the lock out switch (114.0)
and the opening spring (64.0).
5. Provide indication of the circuit breaker
status (OPEN/CLOSED), indicate capacitor
energy status (green LED indicates ready,
yellow LED indicates OPEN possible and
red LED indicates error) and number of
operations.
Figure 7: Pole assembly
27.0
20.0
31.0
16.1 16.1
28.0
30.0
16.016.0
60.0
36.0
28.1
63.0
29.2
29.1
48.6
49.0
64.3
48.9
48.0
62.9
62.8
29.1
29.0
40.0
48.9
Identification 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
28.1 Centering ring
29.0 Moving-end connection pad
29.1 Flexible shunt
29.2 Terminal clamp
30.0 Vacuum interrupter
31.0 Fixed contact
36.0 Moving contact
40.0 Moving-end pole head
48.0 Insulating coupler
48.6 Angled lever
48.9 Guide link
49.0 Contact pressure spring
60.0 Mechanism housing
62.8 Coupling rod
62.9 Coupling link
63.0 Jack shaft
64.3 Lever
14
Figure 8: Magnetic-actuator operating mechanism
Circuit breaker shown in OPEN position.
105.1
105.0
109.0
105.2
105.2
63.0
54.0
104.0
54.1
53.0
60.0
106.0
106.1
106.4
113.0
113.0
106.1
63.5 64.3
101.1
101.3
113.0
106.3
64.0
62.9
101.5
62.8
101.0
101.1
103.0
114.0
59.0
58.0
68.0
102.1
106.0
68.1
Identification Description
53.0
54.0 Open pushbutton (red)
58.0 CLOSED/OPEN indicator
59.0 Operations counter
60.0
62.8 Coupling rod
62.9 Coupling link
63.0 Jack shaft
63.5 Lever phase B
64.0 Opening spring
64.3 Lever
68.0 Auxiliary switch
101.0 Magnetic actuator
101.1 Side plate
101.3
101.5 Safety guard
102.1 Manual opening shaft
104.0
105.0 Controller board
105.1
105.2
106.1 Capacitor board
106.3
106.4
109.0 Control panel
113.0 Position switches
114.0 Lockout switch
Close pushbutton
(black)
Operator mechanism
housing
Coil of magnetic
actuator
Power supply for
controller board
LEDs:
Red LED indicates error
(energy not sufficient
for operation).
Yellow LED indicates
open possible (energy
sufficient for OPEN
position).
Green LED indicates
ready (energy sufficient
for OPEN-CLOSE-OPEN
cycle).
Connector (disconnect
to discharge capacitors)
Connector for each
capacitor board
Red LED - capacitor
discharge state
15
Construction
The essential parts of the operating
mechanism are shown in Figure 8: Magneticactuator operating mechanism on page 15.
The essential parts of the magnetic actuator
(101.0) are the side plates, cover plate,
permanent magnets, coupling rod, coil,
armature parts and bearing plate for
armature.
The magnetic actuator (101.0) is connected
by the side plates with the mechanism
housing (60.0). Also, the magnetic actuator
(101.0) secures to the jack shaft (63.0). The
magnetic actuator (101.0) requires no
maintenance.
If the circuit breaker is stored for a long time
without control power, the capacitors will
fully discharge. Charge the capacitors at least
every two years for a minimum of three
hours. Apply control power to the power
terminals as shown on the drawings specific
to the order on which the circuit breaker was
supplied. Refer to the example of circuit
diagram shown in Figure 14 on page 24.
Mode of operation
The capacitors have been charged, the
mechanism is ready for an operation at any
time. This is indicated by the green LED
(105.1) on the front panel. If the control
voltage fails, the stored energy is sufficient
for one open operation initiated by the
operator-mounted Open pushbutton (54.0)
within five minutes. Within five minutes after
loss of operator control power, the circuit
breaker can perform one open operation
initiated by a remote command if the remote
command is from a wet (powered) contact.
Closing
There are two different closing operations
possible:
Remote (electrical)
Local (electrical) (by pressing the
pushbuttons).
When a close command is initiated, the
capacitors supply current to the actuator coil,
creating an electromagnetic field. This field
adds to the magnetic field of the permanent
magnets. As a result, the coupling rod (62.8)
moves upward. In turn, this transfers force to
the jack shaft (63.0) by means of the
coupling link (62.9), closing the circuit
breaker. Simultaneously, the opening spring
(64.0) is compressed.
Trip-free function for the type SDV7-MA
outdoor distribution circuit breaker
For the type SDV7-MA outdoor distribution
circuit breaker, the trip-free function is
embedded in the controller electronics.
Opening
When an opening command has been given,
a reverse current is supplied to the magnectic
actuator coil (101.3). This cancels the
attractive force between the magnetic
actuator (101.0) and the permanent magnet.
Due to the stored energy of the contact
pressure spring (49.0), the magnetic
actuator’s armature is pushed downwards.
This opening process is supported by the
opening spring (64.0). In the OPEN position,
the opening spring assures that the ambient
atmospheric pressure does not close the
contacts in the vacuum interrupters (30.0).
16
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