Instruction Manual for EExde Motors - Rotor UK

Three-phase Squirrel-cage Explosion-proof
Type: AOM…, AVM…, AKM…
Electric Motors
Handling, Service and Maintenance Manual
Introduction
This Manual determines the main directions for mounting, connecting, operating, maintenance and
repairing of three-phase squirrel-cage explosion-proof electric motors.
Safe and trouble-free performance depends on complying with all operating and maintenance directions
described in individual paragraphs of this Manual in conjunction with data contained on motors’
nameplates and in manufacturers’ catalogues and local regulations.
It is a necessity that mounting, operating, maintenance as well as inspections are carried out by fully
qualified personnel, trained for working and operating of electrical equipment while supervised by a
person professionally qualified and certified as fully trained.
Terminology
• Potentially explosive environment
Environment where an explosive atmosphere could occur.
• Explosive gas atmosphere
A mixture of flammable gases, vapours or mists combined with air under atmospheric conditions
exists in such proportions that it may ignite by excessive temperature, arc or spark.
• Maximum surface temperature
The highest temperature, which originates at the worst conditions on whatever part of the surface of
the electrical equipment which could cause ignition of the surrounding atmosphere.
• Enclosure
All walls surrounding live part of the electrical equipment inclusive of covers, cable bushes, shafts,
bars, pull rods, spindles that determine kind of protection against explosion and/or degree of
internal protection (IP rating) of the electrical equipment.
• Flame-proof enclosure “d”
Kind of protection against explosion where parts capable of ignition of the explosive atmosphere are
located inside the enclosure. This enclosure would contain the explosion of the explosive mixture
inside the enclosure, withstand the pressure caused by the explosion as well as the relevant
temperature rise. It would prevent transfer of the explosion to the surrounding explosive
atmosphere.
• Increased safety “e”
Kind of prevention against explosion where additional measures are taken in order to prevent, by
implementing a high degree of safety, temperature rise, sparking and/or creation of electrical arc
inside and on the external parts of the electrical equipment which would not cause these
occurrences during normal operation.
• DE (Drive End)
The end the mechanical energy is being taken.
• NDE (Non Drive End)
The end which is in opposite to the DE.
• Left (right) side
Left (right) half of the motor when looking at the DE.
Standards
For explosion-proof squirrel-cage electric motors the following standards and recommendations are
applicable:
IEC 34-1 Rotating electrical machines. Specification for rating and performance.
IEC 34-5 Degree of protection
IEC 34-6 Rotating electrical machines. Classification of methods of cooling.
IEC 34-7 Specification for symbols for types of construction and mounting arrangements of
rotating electrical machines.
IEC 34-8 Terminal markings and direction of rotation of rotating electrical machines.
IEC 34-9 Permitted noise level.
IEC 34-11 Specification for built-in thermal protection for electric motors rated at 660 V AC and
below.
IEC 34-14 Mechanical vibration of rotating electrical machines of frame sizes 56 mm and above.
IEC 72-1 Standard dimensions and power rating of rotating electrical machines.

IEC 38
EN 50014
EN 50018
EN 50019
Standardised voltages.
Electrical apparatus for potentially explosive atmospheres. General requirements.
Electrical apparatus for potentially explosive atmospheres. Flame–proof enclosure “d”.
Electrical apparatus for potentially explosive atmospheres. Increased safety “e”.
Marking of the electrical apparatus for potentially explosive
atmospheres.
The permitted utilisation of the electrical apparatus is determined by
explosion proof execution described by its marking according to EN 50014.
Explosion-proof marking is written on motor’s nameplate and on the
relevant certificate and consists of the following marks:
EEx
defines that the apparatus complies with one or more kinds of protections against
explosion specified in the EN 50014 standard.
d
designation of the protection against explosion, Flame-proof Enclosure
e
designation of the protection against explosion, Increased Safety
IIB
designation of the Group of the explosion-proof electrical apparatus
H 2
explosive gas of the Group IIC – Hydrogen
T4
Temperature Class designation of the explosion-proof electrical apparatus of Group II
Complete designation of the explosion-proof electric motor
EExde IIB+H 2T4
Electrical apparatus for potentially explosive environment other than
environment where methane is present, with protection against explosion
applicable for the motor is Flame-proof Enclosure and its terminal box is of
Increased Safety. Both are of Group IIB complemented with hydrogen H 2
which normally falls in Group IIC and the Temperature Class T4.
Execution
If not agreed otherwise rated data for continuous Duty Cycle S1 are valid at frequency of 50Hz, ambient
and/or coolant temperature up to +40°C and an altitude up to 1000 metres above see level.
Motors of frame sizes 71 to 100 mm are of protection IP54 and frame sizes 112 to 200 mm are of
protection IP55. Degree of protection of the fan is IP2.. Method of cooling is IC411.
The motor itself is fully Flame –proof according to European Norm
EN 50014 and EN 50018. The terminal box is of Increased Safety according to EN 50014 and EN
50019.
Design
The explosion-proof motors are fully enclosed, fan ventilated three-phase squirrel-cage induction motors
for low voltage application.
The mounting arrangements available are specified in the relevant catalogue as well as in the mounting
arrangement table enclosed with this document.
The basic construction parts, the frame, both endshields, flanges, bearing retainer plates and caps as
well as the terminal box are all of grey cast iron.
The fan is of Al-Si alloy.
Fans of motors of frame sizes 71 to 132 and 200 mm are fitted to the shaft with a key and a key way,
fans of motors of frame sizes 160 and 180 are clamped to the shaft.
The fan cover is of steel sheet perforated 8 x 8 mm at the suction end.
Terminal box is located on top and the cable entry can be turned at 90°.
Terminal box is equipped with one, two or three explosion-proof cable glands on its side depending on
the construction arrangement.
Motors suitable for direct on-line starting are equipped with one cable gland as standard. Motors
suitable for Star-Delta starting are equipped with two explosion-proof cable glands.
Motors which are equipped with temperature gauges of built-in thermal protection are always fitted with
one extra auxiliary explosion-proof cable gland for cabling the temperature gauges to the thermal
protection control system.
Connection terminals are designed as explosion-proof bushes interconnecting the inside of the motor
frame with the inside of the terminal box.
For wiring of the motor it is possible to use copper cables as well as cables with aluminium conductors.
Design of 132M foot mounted and foot & flange mounted motors enables its fitting to 132S fitting
dimensions, similarly 160L and 180L foot and foot & flange motors could be fitted to 160M and 180M
fitting dimensions respectively.
The symmetrical position of the stator packs in the relevant frames enables all flange mounted motors to
be turned through 180° when required in order to choose the position of the terminal box on the DE or
NDE.
Feet of foot and foot & flange mounted motors of frame sizes 71 to 180 mm are cast-on the frames
whereas the feet of the 200 frame are bolted.
DE shaft ends of all frame sizes are equipped with centralising tapped holes and keys with a key way.
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All rotors are dynamically balanced with full key, designation F.
Motors frame sizes 71 to 100 mm are fitted with closed ball bearings, 62 range, lubricated for life.
Motors frame sizes 112 to 200 are fitted with open ball bearings, 63 range as standard. At modified
executions these frame sizes are fitted with closed bearings, lubricated for life.
Detailed description of individual parts of motors can be found in later paragraphs of this manual.
This description of the motor construction is valid for the basic standard execution and some other
executions derived from the standard motors.
The number of executions and their modifications is much larger. It is therefore not possible to describe
them all in this brief description.
Should you have any query please ask your national distributor or directly the manufacturer, Siemens
Elektromotory, s.r.o., manufacturing plant Frenstat.
Health and Safety Instructions
The electrical machines described in this manual make parts of industrial electrical equipment. They
have been designed to relevant recognised technical standards.
Due to their functional electrical and mechanical properties these machines may in certain
circumtances, cause health or material hazard e.g. when misused, incompetently handled, when
insufficiant maintenance is exercised or when subject of unacceptable manipulation.
General criteria for permitted use which means fitting, mounting and operational conditions are
determined by the data contained on the motor‘s nameplate, in the relevant catalogue and possibly in
the technical conditions agreed between the customer and the manufacturer which must be strictly
adhered to.
In case of utilising the motor for a non-industrial application where some extra Health and Safety
measures (e.g. Protection against electric shock) are required, it is necessary to guarantee that these
additional safety measures are taken on the whole equipment at the time the motor is fitted.
Only those measures necessary to be taken when installing in an industrial environment are described
in the operation manual. When installing a motor national, local and other requirements and provisions
specific for the equipment in question must be taken into consideration.
It is supposed that when designing and implementing all mechanical and electrical instalations,
transportation, fitting and commissioning, operation, maintenance and repairs will be carried out and
supervised by qualified personnel suitably trained.
This includes the implementation of general rules for fitting and safety working on electrical equipment
as well as professional use of lifting equipment, binding equipment and tools.
Transportation and storage
Individual motors may be suspended only by their suspension eye bolts. The lifting capacity of the lifting
gear must be chosen according to the weight of the motor marked on the nameplate.
When installing a suitable guidance by rope or span beam must be used.
The eye bolts must be well tightened before lifting. The eye bolts have been designed to withstand the
weight of the motor only so they must not be used for lifting the whole assembly of the motor and the
driven equipment.
Motors suitable for vertical mounting are equipped with additional eye bolts which may only be used for
motor installation. Both bolts must be well tightened before lifting.
Should some of the motors not be commissioned immediately after delivery they must be stored in a
dry, vibration free storage place.
During storage the motors must be protected against permanent moisture, dirt, dust and various
chemical vapours and incompetent handling must be avoided. The storage place must be indoor, clean,
dust-free and without vibrations (v ef ≤ 0.2 mm/s). The storage place must not be heated and maximum
relative air humidity must not exceed 80% at 20°C.
Installation
When installing the motors in a potentially explosive environment all local and national standards and
regulations must be complied with as well as all rules set by the relevant supervising authority.
The kind of Protection against Explosion, explosion-proof equipment Group and Temperature Class is
marked on the motor nameplate.
When installing the motor all measures must be taken in order to prevent the motor being subject to
harmful effects caused by other equipment such as heat radiation, vibration, etc. The terminal box lid,
suction grill of the fan cover, lubricating nipples and motor nameplate must be fully accessible at all
times.
Uniform cooling must be enabled to all surfaces, inclusive of the bottom of the motor, in order to prevent
local excessive increase of the surface temperature.
Cooling air must not be prevented from free inlet and free outlet for air-cooled motors. The dimension
“x” (see the catalogue) must be kept in order to ensure the minimal gap between suction grill of the fan
cover and neighbouring equipment. It is imperative that the hot outlet cooling air must not be re-used as
an inlet air for cooling.
Vertically mounted motors with the shaft down must be equipped with a canopy in order to prevent
foreign bodies entering the fan compartment through the fan cover grill.
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Provision must be made for motors mounted in IM 3031 (IM V3) position to prevent flooding of the
flange and the entering of foreign bodies between the ribs of the motor and its fan cover.
Motors mounted in IM 3011 (IM V1) position have the terminal box located near NDE. It is
recommended that the terminal box of these motors is turned for 90° so that the cable entry can be
made from the free shaft end. Water running alongside the cable will not come in contact with the cable
gland and terminal box side.
Motors installed outdoors must be fitted with a protective shield as prevention against direct sun
radiation in the summer and snow etc. in the winter. The protective shield must not effect motor cooling
in any way.
During adverse operational conditions high temperatures over 100°C might occur locally on the surface
of the motor. Relevant provisions must prevent direct contact of personnel with these temperatures. No
temperature sensitive parts such as cables, conductors and/or electronic devices must be laid onto or
fitted to these surfaces.
Fitting
The motor must be fitted in the position that has been determined by the mounting marked on motor
nameplate. Fitting in any other position must be consulted with the national distributor or the
manufacturer.
Mechanical connection with the driven equipment can be achieved through a flexible coupling or other
transmission elements whilst ensuring that the permitted load of the shaft end (obtain from
manufacturers’ catalogue or ask your national distributor) is not exceeded. Additionally for the correct
mechanical connection provisions contained in the operation manual of the driven equipment must be
taken into consideration.
Measuring of deviations during the coupling adjustment is shown on Fig.1.
Fig.1 Coupling adjustment
Permitted deviations of the correct coupling adjustment are shown in the following table
Permitted Fitting Deviations
Coupling Size D
[mm]
Offset ∆x
[µm]
Angle Deviation ∆y
[µm]
125 70 200
160 70 200
200 and 250 80 220
315 80 220
355 and 400 90 250
It is recommended to make precise adjustment of the coupling without utilising the maximum permitted
deviations from the table above for smooth vibration-free and quiet operation and for utilising full life of
the bearings.
Belt and pulley transmission use is possible only when the relevant standards and provisions regarding
the protection against dangerous effects of static electricity in the specific environment are kept.
Rotors are dynamically balanced with full key as standard and marking “F” could be found on the shaft
front face or inside the key way.
If required by the customer rotors could be dynamically balanced with half key. In this case “H” could be
found on the shaft front face or inside the key way.
All couplings or pulleys that are to be fitted to the motor shaft must be dynamically balanced. The
balancing should be carried out without a key for motors dynamically balanced with full key (F).
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Should the rotor be dynamically balanced with half key (H), it is necessary to fit a coupling or pulley
dynamically balanced with half key.
It is necessary to clean the shaft end to remove the protective conservation layer and lubricate it with oil
before fitting a coupling or pulley. It is recommended that all couplings, pulleys and other parts be
heated before fitting on the shaft end.
Should the fitting be carried out without heating of the part to be fitted it is recommended that a suitable
tool is used.
A suitable puller must be used for pulling the parts fitted on the shaft end and a provision must be made
to prevent destruction of the tapped hole in the shaft end (see Fig.2).
Insert for protection of the tapped hole
Fig.2 Coupling fitting and removing (tapped hole protection)
The motor must stand on a firm base and its feet on a plain metal surface. If necessary thin metal shims
must be put under the feet to prevent pre-tension of the motor. The number of shims should be kept to
the minimum.
It is necessary to check the coupling adjustment after fitting and tightening the fixing screws.
Stable mounting base, precise levelling of the motor, correct balancing of the parts fitted to the shaft end
are all necessary measures for trouble-free quiet operation without vibration.
No excessive force must be exercised when fitting and removing transmission parts.
The keys are secured in the key way during transportation only.
If the motor is double shafted and one of the shaft ends will not be used for connection with driven
equipment it is necessary to remove the key before commissioning. Additional provisions for balancing
must be made should the motor comply with additional requirements for reduced level of vibration.
Provisions must be made to prevent access by personnel to the rotating parts of the motor, coupling,
pulley and/or other transmission elements.
Provision must be made (e.g. fitting a safety valve) for those applications where after disconnecting the
motor due to a fault to prevent a situation where the driven equipment (e.g. a pump) could be driving the
motor (due to reverse flow of the pumped fluid).
Protection against electric shock
Protection against electric shock of parts not normally under voltage must be carried out according to
IEC 364, IEC 479 and IEC 536 as well as according to the valid national rules and standards. An earth
conductor must be connected to the earth terminal of the motor designated by Mark 5019 according to
IEC 417. There are two earth terminals on the motors, one on the outside frame and the other is inside
the terminal box. With regards to the danger of electrocution it is necessary to pay the relevant attention
to all kinds of possible protection against electric shock of all parts not normally under voltage.
Wiring up
The motor must be wired according to the wiring diagram located in the inside of the terminal box lid. It
must be ensured that all inlet conductors make good contact with the motor terminals and that this
contact will be permanent. The voltage marked on the motor nameplate and connection of the motor
terminals must conform to the voltage of the supplying mains.
The size of the inlet cable must be chosen according to the rated current of the motor as well as
conditions depending on the whole equipment, environmental temperature, the way the conductor is laid
down, length of the conductor, etc.
It is possible to carry out the wiring termination utilising the terminals the explosion proof bushes are
equipped with where no cable eyes are required.
The terminal marking used is to IEC 34-8. If multiple bushes are used the terminals are marked by
numbers and on the wiring diagram located inside of the terminal box lid. It is clearly marked which
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number is assigned for which terminal marking as per IEC 34-8. The same marking is also stamped on
the terminal box bottom.
Terminals are marked as U, V, W for motors designed for direct on-line starting.
If connecting the mains with the sequence of phases L1, L2, L3 to terminals U, V, W the motor will
operate in a clockwise direction of rotation. In order to change the direction of rotation it is necessary to
swap any of the two inlet phases. All motors have been designed to run in both directions of rotation.
The way of wiring up of the motors, winding configurations and built-in thermal protection are described
in other paragraphs of this manual.
Motors with temperature gauges must be wired to the thermal protection control system in a way that
prevents an automatic start-up of the motor after the temperature has cooled down and the temperature
gauges have connected back up in order to eliminate a non-expected start-up of the driven equipment.
The start-up should be carried out in full awareness of the operation by the operation personnel.
Before the terminal lid is fitted back on the following must be checked:
• inlet conductors and possibly the links in the terminal box must comply with the wiring diagram
located in the terminal box lid as well as with the voltage of the supplying mains.
• the inside of the terminal box must be clean and free from cable offcuts and/or other foreign objects.
• all nuts on all studs of the bushes are fully tightened inclusive of any auxiliary terminals the motor
may be equipped with but not employed for the application
• the minimum air distances between live parts must be kept (8 mm for ≤ 500V, 10 mm for ≤ 690V, 14
mm for 1kV). No wires from a stranded conductor must stick out.
• inlet conductors must be laid down without any mechanical tension and their insulation must not be
damaged.
• the cable glands not used are fully closed and lifting elements are well tightened (a tool must be
utilised for their release)
• in order to comply with the marked degree of protection all seals and sealed surfaces must not be
damaged or deformed. If the slot tightness itself is secured by the precision of the contacting metal
surfaces it is necessary to clean them and lubricate them with a silicon grease after any
manipulation with them.
• cable glands and blinds to be correctly chosen and fitted with regards to the required protection
against explosion, the way the cable is laid down, diameter of the cable used, etc.
• cable glands and blinds to be tightened correctly
After wiring up the motor the terminal box lid must carefully fitted and screws tightened.
Circuit braking and over-current protection
The motor must be protected against overloading and short circuit according to the relevant standards.
The system of protection measures must be correctly chosen and the protection elements must be
correctly set to the rated current marked on the motor nameplate.
During operation an overloading might occur that could defect or destroy the motor winding and cause
inadequate surface temperature rise. It is therefore necessary to protect the motor by circuit breakers
and fuses.
Fuses should be chosen to be for 60% to 100% higher current than the rated current of the motor. They
protect the motor and the cabling against short circuit. It is therefore necessary to use a circuit breaker
with current characteristics, which protects the motor against overloading. In case of higher short-circuit
capacity of the supplying mains it is necessary to fit fuses before the circuit breakers. It is permitted to
use similar types of protection depending on the current of all three phases.
Motors for rated voltages according to IEC 38 are marked with a range of rated voltages and the
greatest rated current valid for the whole range of voltages marked on the motor nameplate. Deviations
for environment A according to IEC 34-1 are valid for these values.
Temperature gauges, built in thermal protection
Motors may be equipped with temperature gauges, PTC thermistors built-in in the critical part of the
stator winding. The temperature gauges are located in each phase of the stator are connected in series
and terminated to auxiliary terminals of the explosion-proof bushing marked as T1 and T2. They are to
be connected to the thermal protection control system. Temperature gauges allow temperature
sensitive detection of the thermal protection connected to the control system. The type of the thermal
protection is TP111 according to IEC 34-11.
This thermal protection is effective when the motor is subject to insufficient cooling causing thermal
overloading as well as excessive increase of the coolant temperature, gradual mechanical overloading
or long-term drop or increase of the supplying voltage. When the critical temperature rise has been
reached the built-in thermal protection in conjunction with its control system disconnects the motor from
the supply.
The built-in thermal protection is a simple but effective complement of the over-current protection under
those fault conditions where the over-current protection is not able to protect the motor at all times.
The relevant wiring diagram and its connection is described under paragraph Terminal Box Assembly.
During operation it is possible to check the functionality of the thermal protection by establishing the
continuity of the thermistor circuit by measuring the resistance of the circuit while the control system is
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disconnected. At the temperature gauge temperature 25°C ± 5°C the resistance of the thermal
protection circuit must not be greater than 800Ω.
It is possible to carry out the resistance measuring by standard measuring instruments but the voltage
applied to thermistor circuit must not exceed 4.5V. All relevant rules applicable for the environment in
question must be complied with during measuring.
It is necessary to connect the thermal protection to its control system by a separate cable to avoid
voltage induction to the thermal protection circuit from the supplying power cable. The Thermal
Protection Connection Diagram can be seen bellow (Fig.14).
Supply for motors through frequency inverters must be always operated with fully functional built-in
thermal protection.
The thermal protection control system must be certified by a recognised certification body for use with
explosion-proof electric motors.
Fig.14 Thermal Protection Connection Diagram
Insulation test
Before commissioning after long term storage or after putting out of operation the insulation resistance
of the winding must be checked. The insulation resistance of the motor winding is measured with DC
voltage against the frame. This must be also carried out during inspection.
The limit value of the smallest insulation resistance, critical insulation resistance and measuring voltages
for motors with rated voltage up to
1000 V must comply with the following.
• New, cleaned or repaired winding R i ≥ 10 MΩ U zDC = 500V
• Critical insulation resistance after 0.5 MΩ/kV U zDC = 500V
some time of operation
The above data are applicable for measuring at an ambient temperature of 25°C.
New dry windings have their insulation resistance higher than the limit insulation resistance. If the value
of the insulation resistance is close to the smallest limit value, the cause of this occurrence may be
humidity or pollution. If the value is lower it is necessary to establish the cause of the occurrence. It
may be that the winding needs drying.
The insulation resistance of the clean winding is directly dependent on temperature. It drops to half its
value when the temperature has risen for 10K. This means that if the temperature has risen for 50K the
insulation resistance drops to 1/32 of the initial value.
During the time of operation the insulation resistance can decrease due to the environment and
operational influence.
The critical value of the insulation resistance at the temperature of 25°C is possible to calculate from the
rated voltage multiplied by specific value of the critical insulation resistance.
For example the critical insulation resistance for voltage 690 V is:
0.69 kV x 0.5MΩ/kV = 0.345 MΩ
If during operation the value of the insulation resistance is higher than the value of the calculated critical
insulation resistance the motor is possible to use further.
If, however, the insulation value is close to the calculated critical value it is necessary to dry the winding
and possibly dismantle the motor, clean the stator and dry it out.
If the insulation value is close to the critical value it is necessary to ensure that the insulation resistance
checks are carried out in short intervals.
Measuring of the insulation resistance of low voltage motors is carried out by using measuring
instruments with voltage 500 V. Subsequent measuring by instruments with voltage 1000 V is permitted
only when the result of the measuring with 500 V was found to be higher than the critical insulation
resistance.
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Drying of the motor winding can be carried out by brought up heat (in drying ovens) or by heat
generated inside the motor when a DC current is applied. When drying by DC current its value must not
exceed 50% to 70% of the AC rated current of the relevant winding. It is recommended that the
individual windings are connected in a way that uniform load to each phase is applied. It is
recommended to increase the DC current gradually and if the motor seems to be more damp then the
increase of the DC current must be slower.
When drying in an oven the temperature of the air must not exceed 90°C. If the motor seems to be
more damp the increase of the drying air temperature must be slower.
It is necessary to measure the winding temperature and check the insulation resistance when drying.
Commissioning of the motor
Preparation
It is necessary to check the following after fitting or inspection:
• The fitting and operational conditions comply with the data specified on the motor nameplate
(voltage, current, connection, mounting, explosion-proof rating, degree of protection, method of
cooling, etc.).
• The motor is properly fitted and levelled.
• The driving elements, according to their design, must be correctly set and adjusted (tension of the
belts of a belt drive, teeth clearance and top clearance of toothed wheel drive, coupling adjustment,
etc.).
• The minimum permitted insulation resistance must be complied with (valid also after longer
operational break).
• The machine has been connected in a way that the required direction of rotation has been ensured.
• The rotor of the motor could be rotated by hand.
• All fitting screws and bolts must be fully tightened as well as all nuts of the terminal studs.
• All earth wiring has been properly connected as well as the cables for equalising the electric
potential where required.
• Bearings have been lubricated as described in this manual.
• The built-in thermal protection must be connected to its control system and its functionality must be
checked.
• All relevant provisions of protection against electric shock applicable for moving parts as well as for
live parts must be carried out.
These basic provisions is necessary to complement by additional measures where required (for special
executions or additional safety requirements).
Starting
Additionally to the normal commissioning the following provisions are recommended after fitting or
inspection:
• Motor is to be started without load.
• The noise level and level of vibrations is to be assessed in set main points.
• Should the motor not run smoothly or if the noise level is too high the motor must be disconnected
and assessed during the run-out.
• If mechanical running is improved purely by disconnecting the supply the possible cause of the
problem could be found in the electromagnetic part of the motor. If, however, the run does not
improve after disconnecting, the problem will be in mechanical arrangement such as imbalance of
the motor or the driven equipment, insufficient equilising of the system of the machines, etc.
• If the motor is running smoothly it is possible to put it under load. It is necessary to check the
smooth run under load, measure the voltage, the current and the output which should be endorsed
in a Commissioning Report.
• The temperature of bearings, winding, etc should be checked until a stable condition is reached and
endorsed in a Commissioning Report.
Switching off
Disconnect the power supply and let the motor run-out without braking. Do not open the motor terminal
box lid until stationary and disconnected from the power supply and control system.
Operation
Do not open any cover protecting live or rotating parts or any cover necessary for correct guidance of
the cooling air to ensure that the maximum cooling effect is reached during operation.
It is possible to assess the motor functionality according to the changes of the motor operation
compared with correct normal operation. It is necessary that immediate fault assessment and
subsequent rectification of the problem found is carried out in order to prevent major damage.
It is supposed that switching on and off is carried out by means of automatic control.
If the equipment is not in operation for a long period of time regular checks must be carried out to
maintain the motor dryness and the motor must be run on a regular basis (approximately once a month)
or at minimum the rotor must be rotated by hand.
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In case of a long term break in operation the provisions described under Commissioning must be carried
out.
Maintenance
Professionally trained and fully qualified personnel can maintain explosion-proof motors.
It must be ensured that the power supply is disconnected and isolated according to the local provisions
before commencement of any work on the explosion-proof motor, especially before opening any active
parts cover.
As well as the power supply all additional, auxiliary and protective circuits must be disconnected before
commencement of any work.
The basic safety rules:
• Switch the power off.
• Prevent repeated switching on.
• Make sure that there is no power anywhere in the motor.
• Make sure that the motor and the driven equipment are earthed.
• Cover or mark off all the neighbouring active parts.
Inspections, checks and overhauls
The thorough and regular maintenance, inspections and checks are necessary measures in order to
identify and rectify all possible faults in time before they develop into major damage.
It is possible to recommend just general intervals due to the different operational conditions of individual
motors.
The maintenance intervals must be established based on various conditions such as dust settlement,
frequency of starting, kind of load, etc.
The recommended time intervals are based on the assumption of trouble-free operation.
It is necessary to carry out relevant checks, or even inspection, if faults or extraordinary conditions such
as electrical or mechanical overloading or short circuiting occur.
As far as bearing lubrication is concerned see paragraph Bearings and Lubrication.
It is necessary to clean the motor surface as well as any air inlets on a regular basis for example by dry
compressed air. The cleaning interval depends on the degree of soiling.
A provision for air extraction should be made when cleaning by compressed air. Some protective items
such as glasses, respirator, etc. must be worn.
The first inspection
It is recommended to carry out the first general inspection after approximately 500 hours of operation to
establish that:
• all required technical conditions of the operation are complied with (inlet power, bearing
temperature, winding temperature, coolant temperature, etc.)
• no loose fittings can be found
• the motor operation is smooth with no excessive noise or vibrations
• motor fitting is not impaired
All deviations found during checks or inspections as well as all changes must be immediately rectified.
Overhauling
It is possible to carry out overhauling at the same time as maintenance, such as lubrication or grease
replacement, is carried out on low voltage motors.
It is necessary to check the following:
• rectification tolerance of the rotor
• that all fixing screws and bolts as well as nuts on the terminal studs are tightened
• insulation resistance of the winding is at a sufficient level
• cables, conductors, insulation parts and explosion-proof glands are in good condition without any
discoloration.
During general overhauling it is not normally necessary to disassemble the motor. This is normally
carried out only when changing bearings.
Dismantling and mounting of the terminal box, motors, bearings as well as directions for lubrication or
bearing replacement are described in the later paragraphs of this manual.
Repairs and alterations
All repairs and alterations which could influence a protection against explosion is necessary to be
carried out at the manufacturers or at a manufacturer approved repair shop.
Repaired motors and their technical details must fully comply to the approved documentation. Before
any alteration is carried out it is necessary to establish whether such an alteration is permitted whether
the final altered execution is one of the approved executions or whether it is necessary to re-certify the
motor to include the required execution. In order to do that the consent of the manufacturer has to be
sought.
- 9 -

If a major alteration without certification is carried out or if any detail which is part of the protection
against explosion is altered by non-authorised repair shop the certification declared on the motor
nameplate is considered to be void.
Altered motors must be fitted with new nameplates where the relevant repair shop logo is clearly
displayed. The motors must be then certified by a recognised certification body authorised to certify
explosion-proof apparatus.
Replacement of fans, bearings, cable glands, part of the terminals or terminal box mounting near DE or
NDE etc. are classified as alterations which do not effect protection against explosion if carried out by
qualified personnel.
Terminal board assembly and its connection
The terminal board type OEM 100 to 200 has been designed as increased safety “e” (type of explosionproof
protection) according to EN 50014 and EN 50019 and is of protection IP55 according to IEC 34-5.
The terminal board of explosion proof motors suitable for direct on-line starting is equipped by three
main terminals marked U, V, W. Motors suitable for Star/Delta starting or motors suitable for dual
voltage are equipped with six main terminals marked as U1, V1, W1, U2, V2, W2.
Some special executions may be equipped with additional auxiliary terminals for thermal protection.
The following tables show what types of terminal boards are assigned for which motor as well as the
difference between standard and special executions of explosion-proof motors.
Motor
Size
Terminal
Box Type
Starting and
Number of
Terminals
Size of Main Terminals
- 10 -
Terminals
for Thermal
Protection
Earth Terminals
Max
Cross-section
of Conductors
Standard Special Standard Special Internal External Standard Special
71
80
90 OEM 100 M5 M4 or M7x0.75 M4 or M7x0.75 M5 10 6
100
112 DOL/3 Y-∆/6 2xM5
132 OEM 112 M5 M5 2xM5 10
160 OEM 160 2xM5 2xM5 25 25
180 OEM 180 M4 or M5
200 OEM 200 2xM6 2xM6 35 35
Motor
Size
Terminal
Box Type
Terminal
Box
Location
Explosion-proof
rating/
Degree of
Terminal
Box
Turning
Number and Size
of Cable Glands
Max Diameter of the
Cable (mm)
Protection Standard Special S‘d Special
71
80 PG16 2xPG13.5 or PG13.5 & PG16 14 2x12 or 14&12
90 OEM 100
100
112 Top EExeII / IP55 90° & 180° PG21 2xPG16 or PG21& PG13.5 18 2x14 or 18&12
132 OEM 112
160 OEM 160
180 OEM 180 PG29 2xPG29 or 2xPG29& PG13.5 25 2x25 or 2x25&12
200 OEM 200 PG36 2xPG36 or 2xPG36& PG13.5 32 2x32 or 2x32&12
All necessary information about possible terminal board executions available can be found in the
manufacturers’ catalogue. For further details please contact your national distributor.
Motors of frame sizes 71 to 132 with built-in thermal protection are delivered suitable for direct on-line
starting only.
For motors of frame sizes 71 to 100 with built-in thermal protection a multiple explosion-proof bushing is
used.
It is necessary to connect the power cables and the auxiliary circuits according to the wiring diagram
located in the terminal box lid.
Motors frame sizes 160 to 200 with built-in thermal protection are suitable for Direct-on-line starting and
a modified execution suitable for Star-Delta starting or Y/∆ connection could be delivered.
The connecting terminals are part of the explosion-proof bushings. The relevant design of the
explosion-proof bushings can be seen on installation drawings and diagrams.

The basic power explosion-proof terminal rating in relation to motor sizes as well as the torque
necessary for tightening of the nut/stud assembly is shown in the following table:
Motor Size Explosion-proof
Bushing Type
Stud Size Tightening
Torque [Nm]
Cable Clamp
Screw Size
Cable Clamp Screw
Tightening Torque
71 to 132 25.1 M5 2.5 -- --
160 63.2 M6 4 2 x M5 4
180, 200 100.2 M8 8 2 x M6 5
The M4 bolts grade 8.8 used for clamping the bar cable clamp on the bushing stud are necessary to be
tightened using a torque of 3Nm after possible repositioning.
The explosion-proof bushing type 25.1 is used also for connection of the protection current circuits.
Different types of bushings can be also used for this application.
Terminal board assembly options and their arrangements can be found on the drawing shown in the
following table.
Terminal box assembly Terminal box drawing Connection drawing
OEM 100 Fig.3 Fig.4
OEM 112 Fig.5 Fig.6 & Fig.7
OEM 160 Fig.5 Fig 9 & Fig 10
OEM 180 & OEM 200 Fig.8 Fig 9 & Fig 10
Fig.3 OEM 100 Terminal Box
Fig.5 OEM 112 & OEM 160 Terminal Box
Fig.4 OEM 100 Terminal Box - Connection
Fig.6 OEM 112 Terminal Box – Connection Delta
- 11 -

Fig.7 OEM 112 Terminal Box - Connection Star Fig.9 OEM 112, OEM 180, OEM 200
Terminal Box - Connection Delta
Fig.8 OEM 180, OEM 200 Terminal Box
Fig.9 OEM 112, OEM 180, OEM 200
Terminal Box - Connection Star
- 12 -

Bearings and bearing assembly
Motors frame sizes 71 to 100 mm are equipped with closed radial ball size 62 bearings lubricated for
life. Bearing chambers in the endshields are half filled with lithium based lubrication grease. The
chambers are protected from outside by a flame-proof enclosure slot between the endshield and the
shaft.
Motors frame sizes 112 and 132 are equipped with open size 63 bearings without provision for
lubrication.
Motors frame sizes 160 to 200 are equipped with open size 63 bearings with lubrication canal and
nipples.
Modified executions of motors frame sizes 112 and 132 can be delivered with closed bearings lubricated
for life.
Bearing chambers in the endshields are half filled with lithium based lubrication grease. The chambers
are protected from the inside by a flame-proof enclosure slot between the enshield and the shaft and by
a radial oil seal from outside.
For noise and vibration suppression and for bearing protection against excessive vibration the bearings
are axially pre-loaded by wavy washers.
Types of wavy washers can be found in the table below.
The relevant design of the bearing assembly for each individual size of motors can be seen on the
drawings in the motor handbook.
All motor sizes have axially fixed bearings on the NDE.
When installing a motor and fitting transmission elements the thermal dilatation of the shaft end during
the motor operation must be taken into consideration in order to avoid a creation of excessive axial
pressure on the bearings and their subsequent failure.
Bearing rating, radial oil seal rating and wavy washer rating in relation to motor sizes is shown in the
following table.
Motor Size DE and NDE Bearing Radial Oil Seal Axial Wavy Washer
[drawing No., type]
71 6203 2Z C3 5 065 651
80 6204 2Z C3 5 065 515
90 6205 2Z C3 5 065 475
100 6206 2Z C3 5 065 476
112 6306 C3 G30 x 47 x 7 5 065 493
132 6308 C3 G40 x 52 x 7 5 065 519
160 6309 C3 G45 x 65 x 8 EMO – X67
180 6310 C3 G50 x 72 x 8 EMO – X72
200 6312 C3 G60 x 90 x 8 EMO – X86
The maximum permitted temperature of the bearings is 100°C.
Lubrication, replacement of grease
Motors frame sizes 71 to 100 are equipped with closed bearings lubricated for life. These bearings are
fully lubricated for several years. In order to decide to replace a bearing a bearing assessment based
on diagnostic testing and temperature measurement must be carried out.
After dismantling the motor endshield in the case where the bearing need not to be replaced the
endshield chamber must be cleaned and again half filled with new grease.
For motors frame sizes 112 and 132 with open bearings where motor speed does not exceed 1800 rpm
the grease replacement and re-lubrication is carried out after 20,000 hours of operation or after 3 years
from installation, whichever is earlier, operating conditions permitting. Should the motor speed exceed
1800 rpm then the re-lubrication period is shortened to 10,000 hours of operation or 1½ years from
installation, whichever is earlier, operating conditions permitting.
The above indicated periods of time are valid under normal operational conditions.
Should the motor be subject to severe operational conditions such as high environmental temperature,
excessive vibrations, aggressive or corrosive environment etc. it is necessary to shorten the relubrication
period to suit.
The re-lubrication intervals for bearings lubricated by lithium based grease for motors frame sizes 160 to
200 under normal operational conditions are shown in the following table.
Motor Size Bearing Re-lubrication Interval T [hours]
Type 2 pole 4 pole 6 pole 8 pole
160 6000 12000 12000 12000
180 ball 3000 6000 12000 12000
200 3000 6000 12000 12000
At severe operational conditions it is necessary to shorten the re-lubrication period to suit. See the
lubrication grease manufacturer’s recommendation.
- 13 -

Motor Dismantling
When dismantling a motor the following sequence of operation must be taken:
• remove the key from the key way from DE shaft (28)
• unscrew the lubrication nipple (21) (for frame sizes 160 to 200)
• unscrew fan cover fixing screws (70) and remove them together with the spring washers
• remove the fan cover (25)
• remove the circlip (37) (for frame sizes 71 to 132 and 200) or loosen the clamping arrangement
(frame sizes160 and 180) of the fan
• remove the fan (24)
• remove the fan key (38)
• unscrew the fixing screws (73) (together with the spring washers) of the bearing cap (2) on DE.
• remove the external bearing cap (2) on DE (frame sizes 122 to 200)
• remove axial wavy washers (29)
• unscrew and remove the fixing screws (74) (together with the spring washers) of the endshield (3)
on DE
• remove the DE endshield (3) inclusive of the bearing (5) (frame sizes 112 to 200)
• unscrew the fixing screws (71) of the endshield (22) (together with the spring washers) on NDE.
• remove the NDE endshield (22) inclusive of the complete rotor
• protect the winding end against damage when dismantling
Bearing assembly dismantling on NDE (frame sizes 71 to 100)
• release the internal circlip (75) and remove it from the endshield housing
• remove the endshield (22) from the bearing (19)
• release and remove the shaft circlip (27)
• pull-off the bearings (19) from the shaft (1)
• dismantling of the NDE bearing is not required unless the bearing needs changing
Bearing assembly dismantling on NDE (frame sizes 112 to 200)
• release the fixing screws (72) (together with the spring washers) of the external bearing cap (23)
• remove the external bearing cap (23)
• release the shaft circlip (27)
• pull-off the endshield (22) with the bearing (19) from the shaft (1)
• push the bearing (19) from the endshield (22)
• dismantling of the NDE bearing is not required unless the bearing needs changing
Motor assembling
The sequence of operation when assembling an electric motor is reciprocal to the dismantling procedure
but the following provisions must be adhered to:
• an electric motor assembly must be carried out in a clean environment
• suitable tools and fitting fixtures must be used for radial oil seal fitting
• the principles mentioned under Bearings and bearing assembly must be adhered to when
assembling bearings
• it is recommended to replace the DE bearing with the same type
• it is advisable to carry out the assembly of the NDE bearing after removal from the stator
• it is necessary to observe the correct oil seal orientation during assembly
• cleanliness of all internal parts of the motor must be maintained at all times (prevent ingress of
impurities, use clean connecting material)
• bearing internal ring must be heated using an induction heater to reach a temperature of 80°C (max
100°C) before fitting
• all screws, nuts and bolts must be properly tightened using recommended torque
• lithium based lubrication grease must be used, lubrication canals in endshields must be filled with
grease before assembly
• provisions described in the individual paragraphs of this Instruction Manual must be adhered to
- 14 -

List of parts
1 Shaft
2 DE external bearing cap
3 DE endshield
5 DE bearing
7 Terminal box lid
9 Terminal box
11 Internal earth terminal
12 External earth terminal
15 Stator pack (without winding)
16 Frame
17 Rotor pack with squirrel cage
18 Stator winding
19 NDE bearings
21 Lubrication nipple
22 NDE endshield
23 NDE external bearing cap
24 Fan
25 Fan cover
27 NDE bearing shaft circlip
28 Shaft end key
29 Wavy washer
34 Terminal box bottom wall
35 Bushing
37 Fan circlip
38 Fan key
46 DE oil seal
53 Terminal box lid gasket
61 NDE oil seal
75 NDE bearing endshield circlip
Fig.11
AOM71 - AOM100
- 15 -

Fig.12 AOM112 - AOM160
Fig.13 AOM180 & AOM200
- 16 -

MOTOR MOUNTING ARRANGEMENT TABLE
- 17 -