Eaton IZMY Series User manual

Instruction Manual MN013020EN
IZMY Series Air Circuit Breakers Instruction Manual
Instructions apply to:
IZMY16 IZMY25/40

ii
Instruction Manual MN013020EN
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
WARNING
The warnings and cautions included as part of the
procedural steps in this manual are for personnel
safety and protection of equipment from damage.This
example of a typical warning is intended to familiarize
personnel with the style of presentation.
WARNING
IZMY Series circuit breakers are provided with safety
features. Nevertheless, the voltages, currents, and
power levels available around operational equipment
are extremely dangerous. Under no circumstances
should interlocks and other safety features be made
inoperative, as this may result in death, bodily injury,
or property damage.
WARNING
IZMY Series circuit breakers should not under any
circumstances be applied outside their nameplate
ratings. Operation outside of these ratings could
result in death, bodily injury, or property damage.
WARNING
Never attempt to disable any interlocks. Doing so
could result in an electrical fault that could result in
death, bodily injury, and/or equipment damage.
WARNING
Failure to inspect, clean, and maintain circuit breakers
can reduce equipment life or cause the equipment
to not operate properly under faulty conditions. This
could result in equipment damage, bodily injury, or
even death.
WARNING
Arc chutes and their cover plates must always be
secured properly in place before a breaker is installed
in its compartment. Failure to do so could result in
equipment damage, bodily injury, or even death.
WARNING
The circuit breaker mechanism contains stored
mechanical energy and moving parts and should be
operated with the front cover and arc chutes in place.
Parts may move forcefully and without warning. If the
front cover or arc chutes have been removed, limit
contact to the handle and buttons. Failure to do so
may result in serious bodily injury.
CAUTION
Do not attempt to lift a breaker or cassette with ordinary
crane hooks or chains. Damage to vital circuit breaker
parts could result. Use two appropriate lifting straps when
using any type of lifting device.
CAUTION
Make certain that the cassette is properly mounted or
seated securely on a work table before attempting to
have the breaker fully extended on the cassette’s drawout
rails. Failure to comply could result in the cassette tipping
forward resulting in equipment damage and/or bodily
injury.
CAUTION
Do not store equipment on its back. This could result in
equipment damage.
CAUTION
It is important to take care when placing a drawout circuit
breaker on its extension rails. If the circuit breaker is not
properly seated on the rails, the breaker could fall causing
equipment damage and/or bodily injury.
CAUTION
Inspection and maintenance procedures should be carried
out only by personnel familiar with the hazards associated
with working on power circuit breakers. Additionally, they
should become familiar with the specifics associated with
IZMY Series circuit breakers as presented in this manual.
IMPORTANT
Please read and understand these instructions before
attempting to unpack, install, operate, or maintain this
equipment. Study the breaker and its mechanism carefully
before attempting to operate it on an energized circuit.
IMPORTANT
A circuit breaker stored for any length of time should be
operated a minimum of five times before it is placed in
service.
IMPORTANT
Different degrees of access to push-buttons on the front
of the circuit breaker can be achieved through the use of
optional accessory devices.
IMPORTANT
Before doing any work, make sure a drawout breaker is
levered out to the TEST, DISCONNECT, or WITHDRAWN
position. During the levering out and levering in of the
circuit breaker, be aware of any signs that would indicate
that the levering process is not working properly. If
working on a fixed circuit breaker, bus systems should
be de-energized for convenience and safety. All circuit
breakers should be switched to the OFF position and the
mechanism springs discharged.
!
!
!
!

iii
Instruction Manual MN013020EN
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Purpose
This instruction manual is expressly intended to cover
the installation, operation, and maintenance of IZMY air
circuit breakers. These circuit breakers may be supplied as
part of complete switchboard assemblies or as separate
components. This manual applies only to the circuit breaker
and (if drawout) its mating cassette. In the case of fixed
circuit breakers, certain sections of this leaflet, referring
to such items as position interlocks and the drawout
mechanism, will not apply.
Trip units associated with the IZMY air circuit breakers will
be addressed in a general manner in this leaflet. Specific trip
unit details and time-current characteristic curves are covered
in separate documents specific to the trip units.
IZMY circuit breaker accessory items are just shortly
described in this leaflet. Field installation instructions for such
items, however, are covered in individual instruction leaflets
specific to the accessory.
For application information, consult Eaton or see applicable
Product Guides, Technical Documents, and Industry
Standards.
Safety
All safety codes, safety standards, and/or regulations
must be strictly observed in the installation, operation, and
maintenance of this equipment.
WARNING
The warnings and cautions included as part of this
booklet are for personnel safety and protection of
equipment from damage. An example of a typical
warning label heading is shown above to familiarize
personnel with the style of presentation. This will help to
ensure that personnel are alert to warnings. In addition,
cautions, similar to warnings, are boldface.
All possible contingencies that may arise during installation,
operation or maintenance do not purport to be covered by
this manual. If further information is desired by purchaser
regarding particular installation, operation, or maintenance of
particular equipment, contact the local Eaton representative.

iv
Instruction Manual MN013020EN
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Contents
SECTION 1. CIRCUIT BREAKER OVERVIEW ..................................................1
Usage and scope of application ................................................................ 1
Normal operation, installation and transportation conditions .......................................... 1
SECTION 2. CIRCUIT BREAKER STRUCTURE.................................................2
External structure – Fixed type ................................................................. 2
External structure – Drawout type .............................................................. 2
Internal structure: Fixed/drawout types............................................................
3
SECTION 3. CIRCUIT BREAKER INSTALLATION ...............................................4
Drawout circuit breaker installation .............................................................. 4
Fixed circuit breaker installation ................................................................ 4
Power loss (at ambient temperature of +40°C) .................................................... 4
Derating factors............................................................................. 5
Recommended bus bar specifications ........................................................... 5
SECTION 4. ACCESSORY .................................................................6
Closing release ............................................................................. 6
Shunt release .............................................................................. 6
Motor operator ............................................................................. 6
Internal auxiliary contact ...................................................................... 7
Undervoltage release ........................................................................ 7
Interphase partition .......................................................................... 7
Position cell switch .......................................................................... 8
Latch check switch (LCS)...................................................................... 8
Overcurrent trip switch (OTS) .................................................................. 8
Door escutcheon ............................................................................ 8
External neutral current transformer ............................................................. 8
Mechanical interlock ......................................................................... 9
SECTION 5. CIRCUIT BREAKER OPERATION .................................................9
Charging operation .......................................................................... 9
Motor charging ............................................................................. 9
Opening and closing operations ................................................................ 9
Lever-in operation of drawout circuit breaker ..................................................... 10
Drawout circuit breaker position locking ..........................................................11
SECTION 6. OUTLINE AND MOUNTING DIMENSION DIAGRAMS ..............................12
SECTION 7. ELECTRICAL WIRING DIAGRAMS ...............................................24
IZMY16/25/40 electrical wiring diagram ......................................................... 24
Position cell switch electrical wiring diagram ..................................................... 24
SECTION 8. INSTALLATION, OPERATION AND MAINTENANCE NOTICE .........................25

1
Section 1. Circuit breaker overview
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Usage and scope of application
The IZMY series intelligent general-purpose circuit breakers
(hereafter referred to as circuit breakers) are a new-
generation of high-performance air circuit breakers with
advanced technology and comprehensive functions, thus
offering safety and reliability.
The IZMY air circuit breaker series is a fixed or drawout
design using an electronic tripping system. It is designed and
tested for use at nominal voltages of AC 440 V and 690 V.
IZMY series Air circuit breaker
Section 1. Circuit breaker overview
IZMY air circuit breakers are available with continuous current
ratings from 400 A to 4000 A. The circuit breaker nameplate
provides complete rating information.
The circuit breakers feature isolation function, with the
symbol as
“”.
•The electrical and mechanical characteristics are suitable
for ambient temperature of -25°C to +70°C with 24-hour
average values equal to or below +35°C. When above
+40°C, derating is needed for use. See Derating Factor
Table.
•The altitude should not exceed 5000m at the installation
site. When higher than or equal to 2000m, the electrical
performance of the circuit breaker needs to be corrected.
See Derating Factor Table.
•With the maximum temperature at +40°C, the relative air
humidity does not exceed 50%. A higher relative humidity
(RH) is allowed at a lower temperature, such as 90% RH
when at 20°C. Special measurement should be taken for
occasional condensation due to temperature changes.
Normal operation, installation and transportation conditions
•Pollution level: 3.
•Protection degree: IP40 when the circuit breaker is
installed inside cabinet cubicles and the door escutcheon
is installed.
•Utilization category: B.
•Mounting category: IV for the circuit breaker's main circuit,
and III for the remaining auxiliary circuits and control
circuits.
•The vertical inclination does not exceed 5° during
mounting.
•Transportation and storage temperature: -40°C to +85°C.
IZMY16 Fixed type IZMY16 Withdrawable type
IZMY25/40 Fixed type IZMY25/40 Withdrawable type

2
Section 2. Circuit breaker structure
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Section 2. Circuit breaker structure
External structure – Fixed type
External structure – Drawout type
Secondary terminal
Bracket
Trip unit (not applicable on switch disconnectors)
Open/Closed indication
Released/Charged indication
Nameplate
Manual charging handle
Closing button
Opening button
Fault tripping indicator/Reset button (not applicable
on switch disconnectors)
1
2
3
10 9 8 7
4 5 6
9
8
7
6
5
4
3
2
1
10
Secondary terminal
Cassette
Trip unit (not applicable on switch disconnectors)
Position locking device
Lock catch button
Three-position indication
Nameplate
Open/Closed indication
Released/Charged indication
Manual charging handle
Closing button
Opening button
Fault tripping indicator/Reset button (not applicable
on switch disconnectors)
1
2
3
4 5 6 7
8
10111213
9
8
7
6
5
4
3
2
1
10
11
12
13
9

3
Section 2. Circuit breaker structure
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Internal structure: Fixed/drawout types
1
2
3
4
5
6
7
8
9
10
11
13
14
15
16
12
9
8
7
6
5
4
3
2
1
15
16
14
13
12
11
10
Arch chamber
Shunt release
Undervoltage release or
second shunt release
Secondary terminal
Delivery handle
Operating mechanism
Basic device
Trip unit
Reset button
Opening button
Closing button
Cover
Auxiliary contact
Closing (Spring) release
Charging handle
Charging motor

4
Section 3. Circuit breaker installation
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Section 3. Circuit breaker installation
Drawout circuit breaker installation
1. Remove the basic device of the circuit breaker (see lever-
out operation for more details on Section 5)
2. Mount the circuit breaker into the cabinet:
Circuit breaker
IZMY
Hexagon head bolt
GB5783-
Nut
GB6170-
Washer
GB97 GB93-
IZMY16 M10x30 M10 Φ10
IZMY25 M12×30 M12 Φ12
IZMY40 M12×30 M12 Φ12
Notes: See below diagram for detailed mounting methods and
locations.
3. Lever the basic device of the circuit breaker into the
cassette (see circuit breaker lever-in operation for more
details on Section 5)
Fixed circuit breaker installation
Place the circuit breaker into the cabinet.
Circuit breaker
IZMY
Hexagon head bolt
GB5783-
Nut GB6170- Washer GB97
GB93-
IZMY16 M10×30 M10 Φ10
IZMY25 M12×30 M12 Φ12
IZMY40 M12×30 M12 Φ12
Note: Detailed mounting methods and positions are shown
below.
Nut
Washer
Hexagon
head bolt
Power loss (at ambient temperature of +40°C)
Power loss is the total power consumption measured when
the rated current of frame level (In) passes through the circuit
breaker.
Power loss (W)
Breaker model Fixed type Drawout type
IZMY16 1600 A frame 123.5 331.5
IZMY25 2500 A frame 356.8 823.4
IZMY40 4000 A frame 486.7 856.8
Nut
Washer
Hexagon
head bolt

5
Section 3. Circuit breaker installation
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Derating factors
When the working ambient temperature is greater than +40°C, the continuous current carrying capacity can be corrected with
reference to below table:
Model Rated current (A) +40°C +45°C +50°C +55°C +60°C +65°C +70°C
IZMY16 1600 A frame 400-1250 1 1 1 1 1 1 1
1600 1 1 1 0.95 0.93 0.87 0.8
IZMY25 2500 A frame 400-2000 1 1 1 1 1 1 1
2500 1 1 1 1 0.99 0.94 0.88
IZMY40 4000 A frame 2000-2500 1 1 1 1 1 1 1
3200 1 1 1 0.95 0.92 0.89 0.85
4000 1 0.95 0.92 0.89 0.85 0.82 0.8
When the attitude is higher than or equal to 2000 meters at the installation site, the electrical performance of the circuit breaker
can be corrected with reference to below table:
Altitude (m) 2000 3000 4000 4500 5000
Power frequency voltage
withstand (V)
5000 4500 3500 3000 2900
Operating voltage 440/690 440/690 440/690 440/690 440/690
Short-circuit breaking capacity
correction factor
1 0.83 0.71 0.66 0.63
Operating current correction
factor
IZMY16 1600 A frame 1 0.98 0.93 0.9 0.87
IZMY25 2500 A frame 1 1 1 1 0.97
IZMY40 1600 A frame 1 0.93 0.88 0.85 0.82
Note: The derating correction factor is only for the maximum current in the frame.
Recommended bus bar specifications
Rated frame current Inm (A) Rated current In (A)
Recommended bus bar dimensions
No. of bars
Horizontal outgoing Vertical outgoing
Dimensions (mm x
mm)
IZMY16 1600 A frame 400 2 / 50×5
630 2 / 50×6
800 2 / 50×10
1000 2 / 50×10
1250 3 / 50×8
1600 3 / 50×10
IZMY25 2500 A frame 400 2 / 80×5
630 2 / 80×5
800 2 / 80×5
1000 2 / 80×5
1250 3 / 80×5
1600 2 / 80×10
2000 3 / 80×10
2500 4 / 80×10
IZMY40 4000 A frame 2000 3 2 100×5
2500 2 2 100×10
3200 3 3 100×10
4000 5 4 100×10
The copper bar specifications used in the table are when the circuit breaker is at the ambient temperature of up to 40 °C and installed in an open area, in
accordance with the conventional thermal conditions in GB14048.2.

6
Section 4. Accessory
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Section 4. Accessory
Closing release
After charging, the closing release enables the energy stored
in the operating mechanism to release instantaneously,
allowing the circuit breaker to close quickly.
When used with the Latch check switch (LCS), the closing
release can operate on the circuit breaker only when the
charging spring is fully charged and the tripping latch is in the
re-trip (non-tripping) position. If both conditions are not met,
the closing signal will be invalid until the signal is removed
and re-applied.
•IZMY16/25/40
Power loss table of the closing release
Frame
Insulation
voltage (Ui)
Rated control
voltage Us(V)
Acutating
voltage
Pickup
transient
current
Pickup
transient
power
1600 A 400 V AC230/DC220 (0.85~1.1) Us2.2 A 500 W
AC24/DC24 (0.85~1.1) Us2.5 A 60 W
2500 A
4000 A
400 V AC230/DC220 (0.85~1.1) Us2.5 A 550 W
AC24/DC24 (0.85~1.1) Us5.1 A 264 W
Shunt release
The shunt release enables the circuit breaker to open
remotely.
•IZMY16/25/40
GB9074.8 M4x10
IZMY16
GB93 2×Φ4
GB97 2×Φ4
GB29.2 2×M4×62
IZMY25/40
GB93 2×Φ4
GB97 2×Φ4
GB29.2 2×M4×62
GB9074.8 M4x10
IZMY16
IZMY25/40
Power loss table of the shunt release
Frame
Insulation
voltage (Ui)
Rated control
voltage Us(V)
Acutating
voltage
Pickup
transient
current
Pickup
transient
power
1600 A 400 V AC230/DC220 (0.85~1.1) Us2.2 A 500 W
AC24/DC24 (0.85~1.1) Us2.5 A 60 W
2500 A
4000 A
400 V AC230/DC220 (0.85~1.1) Us2.5 A 550 W
AC24/DC24 (0.85~1.1) Us5.1 A 264 W
Motor operator
The circuit breaker offers motor charging and automatic
recharging functions (manual charging is also available for the
circuit breaker)
•IZMY16/25/40
Rated control voltage
Us(V)
AC24/
DC24
AC230/
DC230
Actuating voltage (0.85~1.1) Us
Power loss 1600 A frame 80 W 80 VA
2500 A frame 150 W 150 VA
4000 A frame 150 W 150 VA
Charging time (s) 5s 5s
GB819 2×M4×10
GB5783 M6×60
GB93 Φ6
GB93 Φ6
M5x12
IZMY16
IZMY25/40

7
Section 4. Accessory
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Internal auxiliary contact
•IZMY16/25/40
Rated operating
voltage Ue(V)
Rated control
capacity
Conventional
thermal
current Ith (A)
Auxiliary contact AC400 800 VA 6
AC230
DC220 300 W
DC110
Undervoltage release
•IZMY16/25/40
In areas prone to thunderstorms or in power grids with
unstable power supply voltage, it is recommended to use
undervoltage release with time delay functions, to prevent
the circuit breaker from tripping due to short-time voltage
drop. The delay time can be selected from 1s, 3s, 5s, to 10s
by users. For special requirements on the delay time, please
contact Eaton.
Rated operating voltage Ue(V)
AC24/
DC24
AC230/
DC320
Acutating voltage(V) (0.35-0.7) Ue
Reliable closing voltage(V) (0.85-1.1) Ue
Reliable no-closing voltage(V) ≤0.35 Ue
Pickup power IZMY16 263 W 570 W
IZMY25/40 228 W 456 W
Maintaining
power
IZMY16 2.2 W 4 W
IZMY25/40 5.7 W 4.2 W
GB9074.8 M4X10
IZMY16
IZMY25/40
GB9074.8 M4X16
GB9074.8 M4x10
GB29.2 2×M4×62
GB97 2×Φ4
GB93 2×Φ4
IZMY16
IZMY25/40
Interphase partition
The interphase partition is mounted vertically between the
wiring boards in the fixed section of the drawout circuit
breaker, to increase the insulation strength of the busbar
connection.
Counter
The counter calculates the number of operations, which can
be read on the front panel. It is compatible with manual and
electrical operation functions. Only available for IZMY25/40.
Keylock Safe-OFF
The keylock Safe-OFF can secure the opening (OFF) button of
the circuit breaker in its actuated position. The keylock facility
is supplied as a kit for field installation.
How to use:
One lock and one key: The keylock safe-OFF kit is supplied
with one lock and one key. The circuit breaker is not allowed
to close in the locked state;
GB9074.8 2×M4×9
GB9074.8 M4X10
IZMY16
IZMY25/40

8
Section 4. Accessory
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Door escutcheon
The door escutcheon is mounted on the door, and features a
protection level up to IP40. The circuit breaker offers an IP20
protection level when mounted separately. Corresponding
door escutcheon is available for both fixed and drawout circuit
breakers.
External neutral current transformer
The TN-S power distribution system uses a three-pole
circuit breaker, which requires an external neutral current
transformer to be equipped with. The ground-current N-phase
transformer only measures the N-phase current for ground
protection judgement, with its N-phase transformer mounting
direction not subject to the wiring method.
During mounting, be cautious of the following:
Twisted-pair wires are available on the external neutral
current transformer, with Code No. 23 and 24 on them to
connect corresponding secondary terminals. Simply follow
the code numbers on the conductors to connect to the
secondary terminals.
Position cell switch
Three sets of switches are available to indicate the current
position of the circuit breaker (Connected, Test,
Disconnected). The corresponding switch will be switched on
when the circuit breaker is in a certain position
Latch check switch (LCS)
A latch check switch (LCS) indicates when the circuit breaker
is “ready to close” (charged and not held tripped).
The LCS for Remote Indication consists of one Form C
contact wired to the circuit breaker secondary contacts (31,
32 and 33) for integration into external control schemes.
Screw M4*8
Waist round hole
Overcurrent trip switch (OTS)
An overcurrent trip switch (bell alarm) provides an electrical
indication when a circuit breaker trips as a result of the trip
unit. Opening as a result of a circuit breaker’s manual open
button, shunt trip, or undervoltage release does not cause
the overcurrent trip switch to operate. Overcurrent trip
switches are available in two switch combinations only.
Position
indication
mounted inside
the switch

9
Section 5. Circuit breaker operation
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Mechanical interlock
Mechanical interlocks are available to interlock the operation
of two or three IZMY Series circuit breakers. The mechanical
interlock holds one or more circuit breakers tripped (prevents
closure) when others are closed.
Consult the instruction leaflet for details.
Circuit breaker 1
interlocking pieces
Lever 12
Lever 11
Regulating part 1
Steel cable 1
Steel cable 2
clip 2
clip 1
Regulating part 2
Lever 22
Lever 21
Circuit breaker 2
interlocking pieces
R≥100
Note: The steel cable is too long and can be wound
into the shape shown above, but the sum of all bending
angles cannot exceed 720°
Circuit breaker 1 Circuit breaker 2
0 0
0 1
1 0
Notes: 1 = Closed, 0 = Open
Section 5. Circuit breaker operation
Charging operation
Manual operation
When charging, repeatedly pull the handle up and down
several times, until you cannot feel the reaction force of the
handle, indicating the charging is completed. At this point,
the “CHARGED” and “DISCHARGED” indicators are in the
“CHARGED” position.
Motor charging
The motor operator starts charging automatically upon
energization of the control circuit.
Opening and closing operations
Manual operation
•Manual closing
When the circuit breaker is in “CHARGED” and “OPEN”
states, press down the green button (I), and the circuit
breaker will be closed. The “OPEN” and “CLOSED”
indicators are switched from “0” to “1”.
•Manual opening
When the circuit breaker is in closed state, press down the
red button (O), and the circuit breaker will be opened. The
“OPEN” and “CLOSED” indicators are switched from “T”
to “0”.
Press

10
Section 5. Circuit breaker operation
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Motor operation
Closing: Apply the rated voltage to the closing release to
close the circuit breaker when in “CHARGED” and “OPEN”
states.
Opening: Apply the rated voltage to the shunt release to
open the circuit breaker when in the “CLOSED” state.
Lever-in operation of drawout circuit breaker
1. Make sure that the cassette is in the “Disconnected”
position and the crank handle is not in the “handle
moving position hole”. Press the lock catch with your
thumb and pull out the sliding plate in the direction
shown in the figure until it cannot be pulled further.
CAUTION
To pull out the slide plate, make sure to press and hold the
“Lock catch”.
2. Place the circuit breaker’s basic device onto the sliding
plate. After placing it properly, push the circuit breaker’s
basic device inward until it cannot be pushed further. The
operation is shown in the figure.
Press
Lock catch
a
cb
CAUTION
Make sure that the clamping band (a) on the sliding plate
of the cassette fully enters the corresponding groove of the
basic device.Sliding plate part (b) cannot stand out of surface
(c) of the basic device.
3. Push the circuit breaker’s basic device inward until you
hear two “clicks”, which means that the basic device
reaches the “Disconnected” position, and the “sliding
plate’s locking device” locks the basic device.
4 Remove the crank handle.
5. Fully insert the hexagonal head of the crank handle into
the position switch hole of the cassette. Press down the
unlock button and turn the crank handle clockwise to
move the basic device inward (During the process from
the “Disconnected” position to “Connected” position,
every time when a position is reached, the “unlock
button” will be ejected as shown in the figure below.
Press the unlock button to continue rotating the handle)
CAUTION
When the "unlock button" cannot be pressed, slightly shake
the crank handle from side to side until the unlock button can
be pressed down. It is forbidden to test the circuit breaker
when in the connected position.
When the circuit breaker is levered into to this position,
the "unlock button" will be ejected. At this point, the circuit
breaker has fully reached the mounting position, so you can
no longer continue to turn the crank handle clockwise
“Disconnected” position
The primary and secondary circuits are
isolated, and the circuit breaker can be
manually operated without affecting the
operation of the power grid
“Test” position
The secondary circuit is switched on, the
primary circuit is isolated, and the circuit
breaker can be operated manually or by the
motor operator.
“Connected” position
The primary and secondary circuits are
switched on, and the circuit breaker can be
operated manually and by the motor operator

11
Section 5. Circuit breaker operation
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Lever-out operation of circuit breaker’s basic device
1. Remove the crank handle and insert the hexagonal head
of the handle fully into the position switch hole of the
cassette.
2. Press down the position lock button while turning the
handle counterclockwise (During the process from the
"Connected" position to "Disconnected" position, the
"unlock button" will be ejected every time it reaches a
position, thereby locking the handle so that it cannot
continue to rotate. At this point, press the "unlock button"
as shown in the figure below to continue rotating the
handle)
CAUTION
When the "unlock button" cannot be pressed, slightly shake
the crank handle from side to side until the unlock button can
be pressed down.
It is forbidden to test the circuit breaker when in the
connected position.
“Disconnected” position
The primary and secondary circuits are
isolated, and the circuit breaker can be
manually operated without affecting the
operation of the power grid
“Test” position
The secondary circuit is switched on, the
primary circuit is isolated, and the circuit
breaker can be operated manually or by the
motor operator.
“Connected” position
The primary and secondary circuits are
switched on, and the circuit breaker can
be operated manually and by the motor
operator
3. Put the crank handle back to its original place and pull out
the circuit breaker's basic device.
CAUTION
Only when levered to the “disconnected” position, the
handle must be removed before pulling out the sliding plate.
4. Remove the circuit breaker's basic device
CAUTION
Put the sliding plate back to its orginal position until you hear
two “clicks”, indicating that the “lock catch” locks the sliding
plate.
Drawout circuit breaker position locking
To lock the circuit breaker, pull out and padlock the pull rod
when the circuit breaker is in any position. At this point, the
position switching cannot be continued.
1. Pull the pull rod out.
2. Put the padlock through. At this point, the basic device
cannot switch positions.
CAUTION
Remove the crank handle from the position switch hole
before pulling out the position lock’s pull rod.
Pull rod
Lock diameter
6mm optimum

12
Section 6. Outline and mounting dimension diagrams
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
70 70
95
164
180
130.5
2x(6.5x8.5)
2xØ6.5
70 70 70
95
909070
130.5
164
2x(6.5x8.5)
4xØ6.5
254
357
357
324
35
11299.5
46
B
301
95 131.568
74
柜门外边
47
分离位置
357
25
45
12.5
37
2xØ5
51
74
232
47.5 11
47.511
214
324
16
235
135 135
74
232
214
324
16
25.5
25.5
235
135 135
35
253.5 253.5
11×Ø5 11×Ø5
3P 4P
断路器底面
断路器中心 断路器中心 开孔中心
断路器底面
前视图
水平接线
门框开孔
Section 6. Outline and mounting dimension diagrams
Drawout type (IZMY16 400-1600 A)
Current 400-1250 A 1600 A
Dimension B
(mm)
10 15
Front view
Horizontal wiring
Disconnected position
Door escutheon cutout
CB
bottom
CB
bottom
Outside of the door
CB center
CB center
Cutout center
Cutout center

13
Section 6. Outline and mounting dimension diagrams
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
水平接线
前视图
门框开孔
柜门外边
拆卸灭弧室距离
25
12.5
33
45
2xØ11
51
318
336
335
316
2xØ7
7070 70
100 50.5
13.5 13.5
193 123
2x(6.5x8.5)
4x(9x12)
B
65
13.5
100
13.5
140
200
40
81 51
87.5
10×Ø5 10×Ø5
74
214
265.5
235
135 135
19 15.5
232
74
214
265.5
235
135 135
19 15.5
232
35
3P 4P
13.5
100
13.5
246
70 70
50.6
266
2xØ7
4x(9x12)
2x(6.5x8.5)
248
335
266
断路器底面
断路器中心 断路器中心 开孔中心
断路器底面
Fixed type (IZMY16 400-1600 A)
Current 400-1250 A 1600 A
Dimension B
(mm)
10 15
Front view
Horizontal wiring
Door escutheon cutout
CB
bottom CB
bottom
Distance when removing the arc chamber
Outside of the door
CB center CB center
Cutout center Cutout center

14
Section 6. Outline and mounting dimension diagrams
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
前视图
水平接线
门框开孔
11×Ø5 11×Ø5
185.2 185.2
124
248
372
297.7
16.4273
16.6
16.6
49.6
327.2
18.4
185.2 185.2
124
248
372
297.7
16.427349.6
327.2
18.4
57.5
80
50
32
12.5
3×Ø13
3P 4P
522
430
407
430
115 115 115
162.5
277.5
440
175
20
20
152
132.5
4xØ13
4x(13x23)
2020
175
152
115 115
325
132.5
4xØ13
4x(13x23)
430
113
B
92
32
20
175
2082
87
395
46
分离位置
柜门外边
断路器底面
断路器中心 断路器中心 开孔中心
断路器底面
Drawout type (IZMY25 800-2500A)
Current 800-1600A 2000-2500A
Dimension B
(mm)
10 20
Front view
Horizontal wiring
Disconnected position
Door escutheon cutout
CB bottom CB bottom
Outside of the door
CB center CB center
Cutout center Cutout center

15
Section 6. Outline and mounting dimension diagrams
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
水平接线
前视图
门框开孔
8×Ø5 8×Ø5
185.2 185.2
327.2
16.5
273
153
153
9
185.2 185.2
327.2
16.5
273
153
153
9
57.5
3P 4P
381
390
422 537
496
115115
400
38 124
195.8
32
Ø11
4
515
315 200
115115115
124
38
32
195.8
32
390
113
B
53.5
40
299
109
122
124
柜门外边
拆卸灭弧室距离 80
50
32
5.5
94
12.5
3×Ø13
标准型
断路器底面
断路器中心 断路器中心 开孔中心
断路器底面
Fixed type (IZMY25 800-2500 A)
Current 800-1600 A 2000-2500 A
Dimension B
(mm)
10 20
Front view
Horizontal wiring
Distance when removing the arc chamber
Standard type
The shaped part is the lap surface of the busbar
Outside of the door
Door escutheon cutout
CB
bottom
CB
bottom
CB center CB centerCutout center Cutout center

16
Section 6. Outline and mounting dimension diagrams
IZMY Series Air Circuit Breakers Instruction Manual MN013020EN January 2024 www.eaton.com
Drawout type (IZMY40 2000-3200 A)
前视图
垂直接
线
30
42 12.5
50 80
3×Ø13
522
430
407
430
115 115
175
20 20
325
4xØ13
4x(13x23)
132.5
162
440
175
20
20
115 115 115
162
132.5
4xØ13
4x(23x13)
162.5277.5
395
175
20 2082
87
134104
430
柜门外边
46
分离位置
42
标准型
Front view
Vertical wiring
Disconnected position
Outside of the door
Standard type