ABB VM1 Quick guide

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MEDIUM VOLTAGE PRODUCTS
VM1
Installation and service instructions
12 ... 24 kV - 630 ... 2500 A - 16 ... 31.5 kA
Table of Contents
I. Introduction 3
II. Programme for environmental protection 4
1. Packing and transport 5
2. Checking on receipt 6
3. Storage 7
4. Handling 8
5. Description 9
6. Structure 10
7. Operation 14
8. Circuit breaker characteristics 22
9. Installation 38
10. Putting into service 52
11. Maintenance 54
12. Application of the standards for X-ray
emission 57
13. Spare parts and accessories 58

2VM1 - USER MANUAL
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For your safety!
 Make sure that the installation room (spaces,
divisions and ambient) is suitable for the
electrical apparatus.
 Check that all the installation, putting into
service and maintenance operations are carried
out by qualified personnel with suitable
knowledge of the apparatus.
 Make sure that the standard and legal
prescriptions are complied with during
installation, putting into service and
maintenance, so that installations according to
the rules of good working practice and safety in
the work place are constructed.
 Strictly follow the information given in this
instruction manual.
 Check that the rated performance of the
apparatus is not exceeded during service.
 Check that the personnel operating the
apparatus have this instruction manual to hand
as well as the necessary information for correct
intervention.
 Pay special attention to the notes indicated in
the manual by the following symbol:
Responsible behaviour safeguards your
own and others’ safety!
For any requests, please contact the ABB
Assistance Service.

MEDIUM VOLTAGE PRODUCTS 33
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I. Introduction
This publication contains the information needed
to install medium voltage VM1 circuit breakers and
put them into service.
For correct use of the product, please read it
carefully.
Like all the apparatus we manufacture, the VM1
circuit breakers are designed for different
installation configurations.
However, they do allow further technical and
construction modifications (at the customer’s
request) to adapt to special installation
requirements.
For this reason, the information given below may
sometimes not contain instructions concerning
special configurations.
Apart from this manual, it is therefore always
necessary to consult the latest technical
documentation (circuit and wiring diagrams,
assembly and installation drawings, any
protection coordination studies, etc.), especially
regarding any variants requested in relation to the
standardised configurations.
Only use original spare parts for maintenance
operations.
For further information, please also see the
technical catalogue of the circuit breaker.
All the installation, putting into service,
running and maintenance operations
must be carried out by skilled personnel
with in-depth knowledge of the
apparatus.

4VM1 - USER MANUAL
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II. Environmental protection programme
The VM1 circuit breakers are manufactured in
accordance with the ISO 14000 Standards
(Guidelines for environmental management).
The production processes are carried out in
compliance with the Standards for environmental
protection in terms of reduction in energy
consumption as well as in raw materials and
production of waste materials. All this is thanks
to the medium voltage apparatus manufacturing
facility environmental management system.

MEDIUM VOLTAGE PRODUCTS 55
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1. Packing and transport
The circuit breaker is shipped in special packing,
in the open position.
Each piece of apparatus is protected by a plastic
cover to prevent any infiltration of water during
the loading and unloading stages and to keep the
dust off during storage.

6VM1 - USER MANUAL
On receipt, check the state of the apparatus,
integrity of the packing and correspondence with
the nameplate data (see fig. 1) with what is
specified in the order confirmation and in the
accompanying shipping notes.
Also make sure that all the materials described in
the shipping notes are included in the supply.
Should any damage or irregularity be noted in the
supply on unpacking, notify ABB (directly or
through the agent or supplier) as soon as possible
and in any case within five days of receipt.
The apparatus is only supplied with the
accessories specified at the time of ordering and
validated in the order confirmation sent by ABB.
The accompanying documents inserted in the
shipping packing are:
 instruction manual (this document)
 test certification
 identification label
 copy of the shipping documents
 electric wiring diagram.
Other documents which are sent prior to shipment
of the apparatus are:
 order confirmation
 original shipping advice notesany drawings or
documents referring to special configurations/
conditions.
Caption
A Circuit breaker rating plate.
B Drive rating plate.
1 Type of apparatus.
2 Symbols of compliance with Standards.
3 Serial number.
4 Circuit breaker characteristics.
5 Characteristics of the drive auxiliaries.
Fig. 1
A
3
4
5
B
1 2
Before carrying out any operation, always
make sure that the capacitors are
discharged and that the apparatus is in the
open position.
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2. Checking on receipt
Circuit breaker IEC 62271-100
VM1 ... CEI 17-1
NO. ... EXPOSED CONDUCTIVE PART ... kg
RATED VOLTAGE ... kV
LIGHTNING WITHSTAND VOLTAGE ATM. ... kV
RATED FREQUENCY 50/60 Hz
RATED NORMAL CURRENT ... A
SHORT-TIME WITHSTAND CURRENT (...s) ... kA
CLOSING / OPENING TIME ... ms
BREAKING CAPACITY ... kA
MAKING CAPACITY ... kA
AT A VOLTAGE OF ... kV
OPERATION SEQUENCE O-0.3s-CO-3Min-CO
DRIVE IEC 62271-100
MAB ... CEI 17-1
NR. ...
–... ... V ...
–... ... V ...
– ... ... V ...
Manufactured by ABB

MEDIUM VOLTAGE PRODUCTS 77
When a period of storage is foreseen, our
workshops can (on request) provide suitable
packing for the specified storage conditions.
On receipt the apparatus must be carefully
unpacked and checked as described in Checking
on receipt (chap. 2).
If immediate installation is not possible, the
packing must be replaced, using the original
material supplied.
Insert special hygroscopic substances inside the
packing, using at least one standard packet per
piece of apparatus.
Should the original packing not be available and
immediate installation is not possible, store in a
covered, well-ventilated, dry, dust-free, non-
corrosive ambient, away from any flammable
materials and at a temperature between –5 °C and
+45 °C.
In any case, avoid any accidental impacts or
positioning which stresses the structure of the
apparatus.
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3. Storage

BC13 2 A
3
8VM1 - USER MANUAL
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4. Handling
Fig. 2
Version Pole centre
distance Rated current Hole
Fixed 150-210 mm up to 1250 A A
Fixed 275 mm from 1600 to 2500 A A
Fixed 210 mm from 1600 to 2000 A A
Withdrawable 150 mm up to 1250 A A
Withdrawable 210 mm up to 1250 A C
Withdrawable 210 mm from 1600 to 2500 A B
Withdrawable 275 mm up to 1250 A B
Withdrawable 275 mm from 1600 to 2500 A C
Fig. 3
Before carrying out any operations, always make
sure that the capacitors are discharged.
To lift and handle the circuit breaker, proceed as
follows (fig. 2):
• use a special lifting tool (1) (not supplied) fitted
with ropes with safety hooks (2);
• insert the hooks (2) in the supports (3) fixed to
the frame of the circuit breaker and lift. Latch
the hooks (2) into the support holes (3)
according to the type of apparatus (see table);
• on completion of the operation (and in any case
before putting into service) unhook the lifting
tool (1) and dismantle the supports (3) from the
frame.
During handling, take great care not to stress the
insulating parts and the terminals of the circuit
breaker.
The apparatus must not be handled by
putting lifting devices directly under the
apparatus itself. Should it be necessary
to use this technique, put the circuit
breaker onto a pallet or a sturdy
supporting surface (see fig. 3). In any
case, it is always advisable to carry out
lifting using the supports (3).

MEDIUM VOLTAGE PRODUCTS 99
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5. Description
5.2. Service conditions
5.2.1. Normal service conditions
Follow the recommendations in the IEC 60694 and
62271-100 Standards. In more detail:
Ambient temperature
Maximum 
 

apparatus for indoor installatio 
Humidity
The average value of the relative humidity, measured for a

The average value of the pressure of the water vapour without


The average value of the relative humidity, measured for a

The average value of the pressure of the water vapour,


Altitude

5.2.2. Special service conditions

Possible within the limits permitted by reduction of the
dielectric resistance of the air.
Increase in the ambient temperature
Reduction in the rated current.
Encourage heat dissipation with appropriate additional
ventilation.
Climate
To avoid the risk of corrosion or other damage in areas:
with a high level of humidity, and/or
with rapid and large temperature variations, take
appropriate steps (for example, by using suitable electric
heaters) to prevent condensation phenomena.
For special installation requirements or other
operating conditions, please contact ABB.
The VM1 type vacuum circuit breakers are
designed for indoor installation in air-insulated
switchgear.
In respect of the technical characteristics, VM1
circuit breakers are suitable for operation of
electric circuits under normal and fault service
conditions.
The vacuum circuit breakers have particular
advantages when used in systems with a high
frequency of operations and/or which lead to a
certain number of short-circuit trips. The VM1
type vacuum circuit breakers stand out for their
particularly high operating reliability, extremely
long useful life expectancy and for being
completely maintenance-free.
The VM1 type vacuum circuit breakers are
available in the fixed and withdrawable version.
The basic structure is shown in the “Technical
data” section.
5.1. Standards and regulations
5.1.1. Fabrication
The VM1 circuit breakers conform to the following
Standards:
 VDE 0670, part 1000, and IEC 60694
 DIN VDE 0670, part 104, and IEC 62271-100
 DIN VDE 0847, part 4, and IEC 61000-4.
5.1.2. Installation and operation
For assembly and operation, please refer to the
relative regulations, and in particular to:
 DIN VDE 0101, AC electrical plants with voltage
higher than 1 kV
 DIN VDE 0100-410, Installation of electrical
plants up to 1000 V, protective measures
 VDE 0105, Operation of electrical plants
 DIN VDE 0141, Earthing systems for special
electrical plants with rated voltages higher
than 1 kV
 Accident prevention regulations of insurance
institutes against accidents at the workplace or
of comparable organisations
 Safety directives for auxiliary and operating
materials.

1
4
2
3
5
7
8
9
6
11
10
10 VM1 - USER MANUAL
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6. Structure
6.1. Drive structure
The drive is of the magnetic type and basically
consists of the magnetic actuator (6) (fig. 4), the
control module (5), the sensors (10), the
capacitor/s (4) and the kinematics which transmit
the movement to the circuit breaker poles.
The actuator (6) acts on the circuit breaker poles
by means of special kinematics. The capacitor/s
(4) provides/provide the energy required for the
operation.
The mechanical operating positions of the circuit
breaker are detected by two due sensors (10).
The basic version of the circuit breaker is fitted
with the following controls and instruments:
 closing pushbutton “I” (8)
 opening pushbutton “O” (9)
 coupling for manual emergency operation (1)
 mechanical position indicator (2)
 mechanical operation counter (3)
 luminous signalling of the “ready” state (7)
(READY).
It is also possible to install auxiliary open/closed
position contacts (11) (accessory on request).
Fig. 4
6.1.1. Structure of the control module
The control module (5) of the circuit breaker
consists of:
 a microprocessor
 opto-electrical input couplers
 output relay
 electronic power system for controlling the
actuator coils.

MEDIUM VOLTAGE PRODUCTS 1111
Fig. 5 Fig. 6
- The energy available is sufficient for one opening
operation within 60 s from interruption of the
auxiliary power supply.
If the energy stored is not sufficient, the luminous
“READY” signal is off, the “READY” contact is open
and the “NOT READY” contact is closed to indicate
that the circuit breaker is not ready for the
operation.
When there is no auxiliary voltage, the capacitor is
able to keep the circuit breaker operational for
about 2 minutes.
6.1.3. Position sensors
The use of two inductive proximity sensors (fig. 6)
allows the state of the circuit breaker (open -
closed - anomalous intermediate position) to be
determined without the use of auxiliary contacts,
allowing continual monitoring of the system.
The signal of the two sensors is sent to the
electronic control module.
6.1.2. Capacitor
The energy for operating the circuit breaker is
stored in one or two capacitors according to the
circuit breaker model (fig. 5).
The capacitors are designed so that the energy for
an O-C-O operating cycle is supplied without the
need for recharging.
The energy stored by the capacitor is constantly
monitored by means of measuring the voltage of
the capacitor.
The “READY” indication signals application of the
power supply voltage and the “ready” state of the
circuit breaker for the next operation.
The energy stored in the capacitors determines
the position of the READY/NOT READY contacts
and lighting up of the luminous “READY” signal
according to the following criteria.
 Case 1: circuit breaker in the open position.
- The energy available is sufficient for one closing
and opening operation.
 Case 2: circuit breaker in the closed position.
- The energy available is sufficient for one opening
operation.

5
4
3
1
2a
2
2b
7
6
16
15
14
13
12
11
8
10
98a
12 VM1 - USER MANUAL
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6. Structure
Fig. 7
8a Cinematismo di trasmissione del movimento del comando ai poli
dell’interruttore
9 Regolatore della corsa
10 Sensori di posizione
11 Bobina di chiusura
12 Magneti permanenti
13 Ancora mobile
14 Bobina di apertura
15 Dispositivo manuale di apertura di emergenza
16 Struttura di supporto
6.2. Structure of the circuit breaker
poles
The poles are installed in the rear part of the
circuit breaker frame (fig. 7).
The active parts of the poles (vacuum
interrupters) are embedded and protected against
shocks and other external agents.
With the circuit breaker closed, the current flows
from the top terminal (1) to the fixed contact (2a)
in the vacuum interrupter (2), and then through
the moving contact (2b) and the flexible connector
(5) as far as the bottom terminal of the circuit
breaker (4).
The movements of the moving contact are
ensured by the insulating tie-rod (7) and by the
kinematics (8a).
1 Terminale superiore
2 Ampolla in vuoto
2a Contatto fisso
2b Contatto mobile
3 Polo
4 Teminale inferiore
5 Connessione flessibile
6 Molla ammortizzatrice
7 Biella isolante
8 Albero di leva

1
2
3
4
MEDIUM VOLTAGE PRODUCTS 1313
6.3. Basic structure of the with-
drawable circuit breaker
The withdrawable truck (4) (fig. 8), either manual
or motorised, consists of a steel sheet structure
with wheels (3), on which the circuit breaker with
the relative auxiliary components, the isolating
contacts (2) for electrical connection with the
switchgear and the multi-pole connector (1) for
connection of the circuit breaker auxiliary circuits
are installed.
After having been racked into the switchgear and
hooked up, the withdrawable circuit breaker can
take up the following positions: racked-out,
isolated for test (with connector inserted) and
racked-in. The racked-in circuit breaker is
automatically earthed by means of the truck
wheels. The magnetic actuator of the circuit
breaker and the relative controls and indicators,
are accessible from the front. Withdrawable
circuit breakers of the same type and
characteristics are interchangeable. However, the
code of the connector prevents incorrect
combinations between the circuit breaker and
switchgear.
Fig. 8

14 VM1 - USER MANUAL
Magnetic latching in end-of-run position. Magnetic latching and action of the magnetic
field of a coil.
Moving armature in opposing position and
magnetic end-of-run latching.
Fig. 9
coil respectively. The magnetic field generated by
each coil attracts the moving armature and
thereby moves it from one of the latching points
of the permanent magnets to the other. The
capacitors which allow circuit breaker operation,
for a maximum time of two minutes, even in the
case of a drop in the auxiliary voltage, are
provided in the control circuit. In case of
emergency, the circuit breaker can in any case be
opened by means of a special crank handle which
acts directly on the moving armature of the drive.
Compared to a traditional operating mechanism,
the magnetic actuator has few moving parts and
greatly reduced wear even after a high number of
closing and opening cycles.
These characteristics therefore make it practically
maintenance-free.
7.1. Operation of the circuit
breaker drive
7.1.1. Magnetic actuator
The magnetic actuator used in the VM1 circuit
breakers generates the run required to operate
the moving contacts of the interrupters and
integrates all the functions of a traditional
operating mechanism. The magnetic actuator is a
bistable system where end-of-run positions of the
moving armature are reached by means of
magnetic fields generated by two coils (one for
closing and one for opening). The moving
armature is kept in position by permanent
magnets.
The circuit breaker operations are obtained by
means of energisation of the opening or closing
—
7. Operation

MEDIUM VOLTAGE PRODUCTS 1515
 The anti-pumping function ensures that only one
closing-opening cycle is carried out when a closing
command followed by an opening command is
active. The active closing command must be
cancelled and reset for the next closing operation.
 Activation of the input for the closing command
can be locked by means of an external locking
signal.
 The input for the “lock on closing” command must
be energised to be able to close the circuit breaker
(without power it inhibits closing).
7.1.4.2. Additional functions of the control module
- full option version
When the “FULL OPTION” control module is
requested, the following functions are also
available:
 Undervoltage function: controls circuit breaker
opening if the voltage applied drops below the
limit of tolerance (established by the Standards).
The rated voltage value to be monitored is set in
the factory in conformity with the order
specifications. To prevent the function
intervening when the voltage drops below the
specified level (e.g. in the case of motor starting),
it is possible to set a trip time (see par. 7.1.7).
If no voltage is applied to the undervoltage
function input, it is impossible to close the circuit
breaker.
The undervoltage function can be disabled. In this
case, it is possible to open and close the circuit
breaker without applying voltage to the input of
the function. It is also possible to select either the
circuit breaker lock in the open state or permission
to reclose the circuit breaker after an opening
operation for undervoltage (see par. 7.1.7).
 Monitoring function of the actuator closing and
opening coil. This function serves to monitor the
continuity of the closing and opening coils of the
magnetic actuator to detect any faults.
If a fault is detected, the luminous “READY” signal
on front of the circuit breaker turns off and the
“READY/NOT READY” signalling contacts are
activated.
 Additional safety opening command function.
The second input of the control module for the
opening function is designed so that an opening
command is carried out directly even in the case of
a fault in the microprocessor.
7.1.2. Opening and closing operations
The opening and closing operations can either be
remotely controlled by means of the special inputs
provided in the control module, or locally by
pressing the pushbuttons (8 - 9) (fig. 4).
During the operations, the moving armature of
the actuator acts directly on the moving contact
by means of the kinematics (8a) (fig. 7).
7.1.3. Reclosing function
Thanks to the short duration of capacitor
recharging, the drive is suitable for multiple
reclosing operations with O-0,3s-CO-3min-CO
cycle.
7.1.4. Control module
The control module is available in the standard
version and in the full option version.
7.1.4.1. Functions of the control module - standard
version
All the conditions for controlling the opening and
closing commands given to the magnetic actuator
are managed by a microprocessor:
 the power supply voltage must be applied to the
AC/DC converter.
 the capacitor must be sufficiently charged for the
next operation:
Circuit breaker position Operations
Open Closing and Opening
Closed Opening
 the closing coil can only be activated when the
circuit breaker is open
 the opening coil can only be activated when the
circuit breaker is closed
 closing is disabled when an opening command is
active at the same time
 de-activation of the opening or closing coil takes
place when the relative limit position has been
reached.
 WRONG POSITION (auto trip) function: if the final
CLOSED (or OPEN) position is not reached within
70 ms during a closing (or opening) operation, an
opening operation is immediately started to
guarantee reaching a defined safe position in any
case.

16 VM1 - USER MANUAL
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7. Operation
7.1.6. Truck locking magnet (compulsory device)
The locking magnet is inserted in withdrawable
circuit breakers with manual movement and
prevents traverse of the withdrawable truck when
there is no power supply voltage.
It is always provided since it is an integral part of
the safety interlock against racking-out with the
apparatus closed due to any possible fault
situation.
Circuit breaker closed Circuit breaker open Capacity of the capacitor/s
Ready signal: lit Ready signal: lit
Sufficient energy for an O-C-O cycle
Ready contact: closed Ready contact: closed
Not Ready contact: open Not Ready contact: open
Ready signal: flashing Ready signal: flashing
Sufficient energy for a C-O cycleReady contact: closed Ready contact: closed
Not Ready contact: open Not Ready contact: open
Ready signal: flashing Ready signal: off
Sufficient energy for one opening
Ready contact: closed Ready contact: open
Not Ready contact: open Not Ready contact: closed
Ready signal: off Ready signal off:
Insufficient energy for opening
Ready contact: open Ready contact: open
Not Ready contact: closed Not Ready contact: closed
Meaning of the signals according to the charging state of the capacitor/s
Circuit breaker closed Circuit breaker open State of the coils
Ready signal: flashing Ready signal: off
No continuity
the closing coil
Ready contact: closed Ready contact: open in
Not Ready contact: open Not Ready Contact: closed
Ready signal: off Ready signal: off
No continuity
in the opening coil
Ready contact: open Ready contact: open
Not Ready contact: closed Not Ready contact: closed
Meaning of the signals according to the state of continuity of the coils
7.1.5. “READY” signalling
The luminous signal and relative “READY/NOT
READY” contacts signal:
 capacitor/s charged
 detection of the correct “CLOSED” and “OPEN”
positions by the position sensors
 watchdog (function only present on the FULL
OPTION control module).
If the luminous “READY” signal is off or flashing,
please refer to the table below to find the cause.
Note:
To carry out circuit breaker closing it is not sufficient for the
luminous READY signal to be lit and the relative contact
activated. It is indispensable to apply voltage to the logical
“-SL1”: 24 ... 240 V d.c. / a.c. input (input for commanding
locking on closing; this function is the same as the one carried
out by the locking electromagnet in the mechanical operating
mechanism of the VD4 circuit breaker).

MEDIUM VOLTAGE PRODUCTS 1717
3
2
1
3
2
1
3
2
1
3
2
1
4
3
2
4
3
2
4
3
2
4
3
2
4
3
2
4
3
2
4
3
2
4
3
2
1
1
5
5
3
3
2
1
1
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
on off
7.1.7. Circuit breaker control card
N.B. Changing the settings by means of dip-switches must be carried out with the control
module de-energised and the capacitor discharged since the selections set and/or modified
are acquired by the control electronics at the moment it is turned on.
Connector for the
storage capacitor/s
and the actuator coils
Power supply
connector
Connector for:
- closing pushbutton
- opening pushbutton
- luminous “READY” signal
Connector for input signal of
the circuit breaker
open/closed position sensors
Jumper only present in the full
option version.It is not normally
short-circuited and energy
consumption during capacitor
charging is 100 W.If it is short-
circuited, energy consumption
during capacitor charging is
reduced to 50 W (the charging time
is obviously doubled)
pos. 1-2: trip input for
PR12 release
pos. 2-3: standard opening
input
Presetting of the trip threshold for
the undervoltage function
Rated voltage Setting
range
35% ... 70%
(Normally
preset to OFF)
220-240 V
AC / DC
84 V ... 154 V
AC / DC
100-127 V
AC / DC
45 V ... 70 V
AC / DC
48-60 V
DC
21 V ... 33 V
DC
24-30 V
DC
11 V ... 16 V
DC
Input connector:
-SO4(1); -SL1; -SO3; -SO2; -SC2
ANSI self-pumping function
enabled
ANSI self-pumping function
disabled (normally preset)
Disabled (normally preset)
Automatic opening due to low energy of
the capacitor/s
Enabled (on request)
Enabling for closing with undervoltage function activated
Output connector:
DOR; DN; DR; DC2(1);
DO2(1); -DC1; DO1
Enabling for closing only after return of voltage at the undervoltage
input (the circuit breaker re-opens after the set delay time)
Enabling for closing with undervoltage function activated
(1) Full Option version.
(2) If enabled, the SO3 input behaves like a hardware input operation even when there is a
fault in the microprocessor. If disabled, the –SO3 input behaves like a digital opening
input processed by the microprocessor.
Selector not used for the VM1 circuit breaker
(the position selected does not matter)
Safety opening disabled
Safety opening (2)
Safety opening enabled (normally
preset)
Function
disabled(normally
preset)
No delay
Delay: 0,5 s
Presetting of the trip delay
of the undervoltage function
Delay: 1 s
Delay: 2 s
Delay: 3 s
Delay: 4 s
Delay: 5 s

1
2
18 VM1 - USER MANUAL
Fig. 10
—
7. Operation
7.3.2. Interlocks in the case where ABB
withdrawable trucks are used
1) The VM1 circuit breaker can only be closed by
means of the logical input when a voltage of 24
V - 240 V AC/DC is applied (electric lock on
closing).
2) The VM1 circuit breaker can only be closed
when the withdrawable truck is in the test or
service position. In intermediate positions the
closing lock voltage is cut off by the auxiliary
contacts.
3) A mechanical interlock positioned on the
withdrawable truck prevents a closed circuit
breaker from being moved from the test
position to the service position.
4) MV1 circuit breaker can only be racked-in/
isolated if the locking electromagnet in the
truck is supplied and the apparatus (as well as
being open) is in the “READY” state.
7.2. Principle of extinction of the
vacuum interrupter
Given the relatively low static pressure of the
interruption chamber (between 10-4 and 10-8 hPa),
a relatively limited distance between the contacts
is required to obtain high dielectric strength. The
vacuum arc is extinguished on the first passage of
the current through natural zero.
Considering the limited distance between the
contacts, the high conductivity of the plasma of
metallic vapours, the drop in voltage of the arc
and, moreover, the short arcing time, the energy
associated with the arc is extremely limited,
therefore producing benefits for the useful life of
the contacts obtained and, consequently, for the
useful life of the vacuum interrupters.
7.3. Interlocks
7.3.1. Interlocks / protection against
malfunction (for withdrawable circuit
breakers for ABB switchgear)
A series of interlocks is provided to prevent
incorrect operations and/or malfunctions. The
interlocks are the following:
 the withdrawable truck can only be moved from
the test/isolated position to the service position
(and vice versa) if the circuit breaker is open (this
means that first of all the circuit breaker must be
opened).
 the circuit breaker can be closed if the
withdrawable truck is exactly in the defined test
position or in the service position (electric
interlock).
 the circuit breaker can be opened manually in the
service or test position when it is not powered,
but it cannot be closed.
 the switchgear is provided with devices which only
allow connection and disconnection of the plug
connector (1) (fig. 10) in the test/isolation
position.
Any detailed information regarding additional
interlocks, e.g. in connection with the earthing
switch operating mechanism, is given in the
specific order documentation.

1
2 3
MEDIUM VOLTAGE PRODUCTS 1919
Fig. 11
7.3.3. Interlock in the case where non-ABB
withdrawable trucks are used
The VM1 circuit breakers mounted on non-ABB
withdrawable trucks must be fitted with one or
two additional auxiliary contacts interlocked with
the mechanical interlocks. These contacts must
cut off the input voltage directed to the electric
closing lock.
Similarly to what takes place for the auxiliary
contacts on the ABB withdrawable truck,
additional electrical impulses cannot be received
after the first half-turn of the spindle (2) (fig. 10).
The electrical impulses can only be applied again
after the last half-turn. This guarantees that it is
impossible to close the circuit breaker when the
withdrawable truck is in an intermediate position.
It is therefore necessary to implement a
mechanical interlock to prevent movement of a
closed circuit breaker. The slide locking device (1)
(fig. 11) on the circuit breaker (optional accessory
for fixed circuit breakers) can be used for this
purpose: if the VM1 circuit-breaker is closed, the
slide locking device is outside the base plate (2)
(fig. 11).
Figure 11 shows the pawl (3) on the ABB
withdrawable truck. If the circuit breaker is
closed, the pawl (3) cannot be turned
anticlockwise. This prevents movement of the
withdrawable truck and therefore movement of
the circuit breaker.
Note: any additional interlocks must not exert any force on the circuit
breaker drive.
If the interlocking mechanism extends beyond the base of the circuit
breaker housing, suitable measures must be taken to prevent the circuit
breaker from resting on the interlock, for example during transport.

20 VM1 - USER MANUAL
—
7. Operation
7.3.4. Characteristics of the control module
contacts without potential
The contacts without potential are supplied with
special relays.
For the characteristics of the contacts, please see
the table and curves given below.
Notes
– In the case of inductive loads, the contacts must be protected against
overvoltages by means of varistors.
– For the other characteristics, please refer to the IEC 60694.5.4.4.5.4 (Ed.
2.2), Class 3 Standards.
Rated voltage (operating range) 

Maximum power applicable (see curves B and C)  (V a.c. on resistive load)
(V d.c. on resistive load - curve A)
Maximum voltage applicable 

Maximum current applicable 
Rated current 
Maximum contact resistance <
Maximum capacity <
Maximum closing time <
Maximum opening time <
Insulation between contacts and coil 
Resistance with contacts open 
Operating temperature 
Storage temperature 
Mechanical life 
Electrical life 
