Nidec LEROY-SOMER LSA 49.1 IC6 Instruction Manual

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LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
Installation and maintenance

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
SAFETY MEASURES
Before using your machine for the rst time,
it is important to read the whole of this
installation and maintenance manual.
All necessary operations and interventions
on this machine must be performed by a
qualied technician.
Our technical support service will be pleased
to provide any additional information you
may require.
The various operations described in this
manual are accompanied by recommenda-
tions or symbols to alert the user to potential
risks of accidents. It is vital that you unders-
tand and take notice of the following warning
symbols.
Warning symbol for an operation capable
of damaging or destroying the machine
or surrounding equipment.
Warning symbol for general danger to
personnel.
Warning symbol for electrical danger to
personnel.
SAFETY INSTRUCTIONS
We wish to draw your attention to the
following 2 safety measures which must be
complied with:
a) During operation, do not allow anyone
to stand in front of the air outlet guards,
in case anything is ejected from them.
b) Do not allow children younger than 14
to go near the air outlet guards.
A set of self-adhesive stickers depicting the
various warning symbols is included with
this maintenance manual. They should be
positioned as shown in the drawing below
once the machine has been fully installed.
WARNING
The alternators must not be put into
service until the machines in which they
are to be incorporated have been
declared compliant with EC Directives
plus any other directives that may be
applicable.
This manual is to be given to the end
user.
The range of electric alternators and
their derivatives, manufactured by us or
on our behalf, comply with the technical
requirements of the customs Union
directives (EAC).
© - We reserve the right to modify the
characteristics of this product at any time in
order to incorporate the latest technological
developments. The information contained
in this document may therefore be changed
without notice.
This document may not be reproduced in
any form without prior authorisation.
All brands and models have been registered
and patents applied for.
WARNING
This manual concerns the alternator which you have just purchased.
We wish to draw your attention to the contents of this maintenance manual.

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
CONTENTS
1 - RECEIPT............................................................................................................. 4
1.1 - Standards and safety measures.................................................................................4
1.2 - Inspection...................................................................................................................4
1.3 - Identication...............................................................................................................4
1.4 - Storage ......................................................................................................................4
1.5 - Applications................................................................................................................4
1.6 - Usage restrictions ......................................................................................................4
2 - TECHNICAL CHARACTERISTICS .................................................................... 5
2.1 - Electrical characteristics.............................................................................................5
2.2 - Mechanical characteristics .........................................................................................5
2.3 - Options.......................................................................................................................5
2.4 - Excitation system .......................................................................................................5
3 - INSTALLATION .................................................................................................. 6
3.1 - Assembly....................................................................................................................6
3.2 - Checks prior to rst use ..............................................................................................6
3.3 - Terminal connection diagrams....................................................................................7
3.4 - Internal coupling.........................................................................................................9
3.5 - Commissioning ........................................................................................................10
3.6 - Setting up .................................................................................................................10
4 - SERVICING - MAINTENANCE......................................................................... 11
4.1 - Safety measures ...................................................................................................... 11
4.2 - Routine maintenance ............................................................................................... 11
4.3 - Air/air heat exchanger: LSA 49.1 IC6........................................................................ 11
4.4 - Air/water heat exchanger: LSA 49.1 IC8 ...................................................................12
4.5 - Bearings...................................................................................................................13
4.6 - Fault detection..........................................................................................................14
4.7 - Mechanical defects ..................................................................................................14
4.8 - Electrical faults .........................................................................................................15
4.9 - Dismantling, reassembly ..........................................................................................17
4.10 - Table of characteristics ...........................................................................................18
5 - SPARE PARTS ................................................................................................. 19
5.1 - First maintenance parts............................................................................................19
5.2 - Technical support service .........................................................................................19
5.3 - Air/air heat exchanger exploded view: LSA 49.1 IC6 ................................................20
5.4 - Parts list ...................................................................................................................21
5.5 - Air/water heat exchanger exploded view: LSA 49.1 IC8............................................22
5.6 - Parts list ...................................................................................................................23
Disposal and recycling instructions

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
1 - RECEIPT
1.1 - Standards and safety
measures
Our alternators comply with most
international standards.
See the EC Declaration of Incorporation on
the last page.
1.2 - Inspection
On receipt of your alternator, check that it
has not su󰀨ered any damage in transit. If
there are obvious signs of knocks, contact
the transporter (you may be able to claim
on their insurance) and after a visual
check, turn the machine by hand to detect
any malfunction.
1.3 - Identication
The alternator is identied by means of a
nameplate xed on the machine (see
drawing).
Make sure that the nameplate on the
machine conforms to your order.
So that you can identify your alternator
quickly and accurately, we suggest you ll in
its specications on the nameplate below.
1.4 - Storage
Prior to commissioning, machines should
be stored:
- away from humidity (< 90%); after a long
period of storage, check the machine
insulation. To prevent the bearings from
becoming marked, do not store in an
environment with signicant vibration.
1.5 - Application
This alternator is mainly designed to
produce electricity in the context of
applications involving the use of
generators.
1.6 - Usage restrictions
Use of the machine is restricted to operating
conditions (environment, speed, voltage,
power, etc) compatible with the characteri-
stics indicated on the nameplate.

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
2 - TECHNICAL
CHARACTERISTICS
2.1 - Electrical characteristics
This alternator is a machine without
sliprings or revolving armature brushes,
wound as “2/3 pitch”, 6-wire, with class H
insulation and a eld excitation system
available in AREP version (see diagram
and AVR manual).
• AREP three-phase 6-wire
• Electrical option
- R791 interference suppression
Varistor
T1 T2 T3
T4 T5 T6
5+ 6-
R450
STATOR: 6-wire (marking T1 to T6)
Auxiliary windings
MAIN FIELD
Voltage reference
EXCITER
Field
Armature
2.2 - Mechanical characteristics
- Steel frame
- Steel end shields, cast iron pipe
- Regreasable ball bearings
- Mounting arrangement: two-bearing with
SAE ange and standard cylindrical shaft
extension
- Degree of protection : IP 55
2.3 - Options
- Stator temperature detection sensors
- PTC or PT100 (1 or 2 per phase)
- Space heaters
Warning : the supply is still present when
the machine has stopped.
- Bearing detection sensors
For example: coupling space heaters and
PT100 2/phase sensors (see diagram page
9).
2.4 - Excitation system
The AREP excitation system is driven by the
R450 regulator, or any other compatible
model, mounted on the outside of the
machine (see corresponding regulator
instructions and the electrical diagrams
provided with the machine).

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
3 - INSTALLATION
3.1 - Assembly
All mechanical handling operations
must be undertaken using approved
equipment.
Whilst being handled, the machine
should remain horizontal.
• Handling
The generously-sized lifting rings are for
handling the alternator alone. They must not
be used to lift the genset.
Choose a lifting system which respects the
positioning of the rings.
• Double-bearing coupling
- Semi-exible coupling
Careful alignment of the machines is
recommended, checking that the lack of
concentricity and parallelism of both parts
of the coupling do not exceed 0.1 mm.
This alternator has been balanced with a
1/2 key.
• Location
The machine must only be used in the
environmental conditions which are dened
when ordering.
LSA IC6 only:
Warning : the ambient temperature can-
not exceed 50°C.
Fresh air, free from damp and dust, must be
able to circulate freely around the air intake
grilles on the opposite side from the coupl-
ing. It is essential to prevent not only the re-
cycling of hot air from the machine or engine,
but also exhaust fumes.
3.2 - Checks prior to rst use
• Electrical checks
Under no circumstances should an
alternator, new or otherwise, be operated
if the insulation is less than 1 megohm
for the stator and 100,000 ohms for the
other windings.
There are 2 possible methods for restoring
the above minimum values.
a) Dry out the machine for 24 hours in a
drying oven at a temperature of 110 °C
(without the regulator).
b) Blow hot air into the air intake, having
made sure that the machine is rotating with
the exciter eld disconnected.
Note : Prolonged standstill
In order to avoid these problems, we
recommend the use of space heaters, as
well as turning over the machine from time
to time. Space heaters are only really
e󰀨ective if they are working continuously
while the machine is stopped.
Ensure that the alternator has the degree
of protection matching the dened
environmental conditions.
• Mechanical checks
Before starting the machine for the rst time,
check that:
- all xing screws are tight,
- the length of screw and the tightening
torque are correct,
- the cooling air is drawn in freely,
- the protective grilles and housing are cor-
rectly in place,
- the standard direction of rotation is clock-
wise as seen from the shaft end (phase
rotation in order 1 - 2 - 3).
For anti-clockwise rotation, swap 2 and 3.
- the winding connection corresponds to the
site operating voltage (see section 3.3).
WARNING

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
3.3 - Terminal connection diagrams
EXCITER
STATOR
TERMINALS CONNEXION
STANDARD
4 TERMINALS
OPTION
6 TERMINALS
Exciter eld
Armature
Rotating rectiers
Green
Yellow
Red
Black
Aux. windings
MAIN FIELD
4 or 6 terminals according to order
NC : Not connected
DE
NDE
white
blue
N
E
U
T
R
A
L
N
E
U
T
R
A
L

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
• A.V.R. connection
Utilization
leaet Ref. 4531 Optional:
Remote voltage adjustment (remove ST4)
TI // optional
to
to
or
I. Max. in all wires: 10A
Desenergizing
TI04 - CT // OPTIONAL
CT connexion for clockwise direction of rotation For anticlockwise, transpose secondary outputs
Open E 01 for desenergizing
E 01 NOT SUPPLIED BY LS
CCW
See from DE
or
or
CW
THREE PHASE ALTERNATOR
AREP

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
3.4 - Internal coupling
• Standard terminal connection: 6-wire
Any intervention on the alternator
terminals during reconnection or checks
should be performed withthe machine
stopped.
L1(U)
L3(W)
T1
T4
T3
T6
T5
T2
L2(V)
D
60 Hz50 Hz
380 - 415 440 - 480
6 S
N L1 L2 L3
114 114 113 104 104 103 106 106 105 108 108 107 110 110 109 112 112 111
104 104
103
106
106
105 108
108
107 110 110 109 112 112 111 114 114 113
PH1 PH2 PH3 PH1 PH2 PH3
102 101
R1 R2
3PH
Winding
AVR terminal: 0. 380V
Connection code
Voltage / Detection
Drawing N°: LSA491.9.062
REGULATOR
white red red
white
red red
white red
red
white
red red
white
red red
white
red red
PT 100 STATOR
(Alarm)
PT 100 STATOR
(Reserve)
STATOR TERMINAL BOX
Anti condensation
heater
STATOR
Protection connections
In no case should the internal
connections in the terminal box be
subjected to stresses due to cables
connected by the user.

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
• Connection checks
Electrical installations must comply with
the current legislation in force in the
country of use.
Check that:
- The residual circuit-breaker conforms to
legislation on protection of personnel, in
force in the country of use, and has been
correctly installed on the alternator power
output as close as possible to the alternator.
(In this case, disconnect the wire of the
interference suppression module linking
the
neutral).
- Any protection devices in place have not
been tripped.
- If there is an external AVR, the connections
between the alternator and the cabinet are
made in accordance with the connection
diagram.
- There is no short-circuit phase-phase or
phase-neutral between the alternator
output terminals and the generator set
control cabinet (part of the circuit not
protected by circuitbreakers or relays in the
cabinet).
- The machine should be connected with the
busbar separating the terminals as shown
in the terminal connection diagram.
- The alternator earth terminal inside the
terminal box is connected to the electrical
earth circuit
- The earth terminal is connected to the
frame.
The connections inside the terminal box
must never be subjected to stress due to
cables connected by the user.
Diameter M6 M8 M10 M12
Torque 4 Nm 10 Nm 20 Nm 35 Nm
Tolerance ± 15%
3.5 - Commissioning
The machine can only be started up and
used if the installation is in accordance
with the regulations and instructions
dened in this manual.
The machine is tested and set up at the
factory. When rst used with no load, make
sure that the drive speed is correct and
stable (see the nameplate). With the
regreasable bearing option, we recommend
greasing the bearings at the time of
commissioning (see section 4.5).
On application of the load, the machine
should achieve its rated speed and voltage;
however, in the event of abnormal operation,
the machine setting can be altered (follow
the adjustment procedure in section 3.6). If
the machine still operates incorrectly, the
cause of the malfunction must be located
(see section 4.8).
3.6 - Setting up
The various adjustments during tests
must be made by a qualied engineer.
Ensure that the drive speed specied on
the nameplate is reached before
commencing adjustment.
After operational testing, replace all
access panels or covers.
TheAVR is used to make any adjustments
to the machine.

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
4 - SERVICING - MAINTENANCE
4.1 - Safety measures
Servicing or troubleshooting must be
carried out strictly in accordance with
instructions so as to avoid the risk of
accidents and to maintain the machine in
its original state.
All such operations performed on the
alternator should be undertaken by
personnel trained in the commissioning,
servicing and maintenance of electrical
and mechanical components, who must
wear personal protective equipment
appropriate for mechanical and electrical
hazards.
Before any intervention on the machine,
ensure that it cannot be started by a manual
or automatic system and that you have
understood the operating principles of the
system.
Warning : During and after running, the
alternator will reach temperatures hot
enough to cause injury, such as burns.
4.2 - Routine maintenance
• Checks after start-up
After approximately 20 hours of operation,
check that all xing screws on the machine
are still tight, plus the general state of the
machine and the various electrical
connections in the installation.
4.3 - Air/air heat exchanger:
LSA 49.1 IC6
• Primary circuit (hot air)
The air to be cooled ows through the
machine and through the exchanger in a
closed system. The air circulation is
generally ensured by a ventilator locked
onto the machine axle and situated on the
front bearing side. In particular cases
(variable speed ...) the air circulation is
ensured by a motoventilator mounted on
the exchanger casing.
• Secondary circuit (cold air)
Ambiant air is usually used for cooling. The
circulation through tubes is ensured ; either
by a turbine mounted overhanging the back
of the machine on a bearing extension or by
a moto-ventilation mounted on the
exchanger. In order to prevent excessive
overheating caused by the tubes clogging
up, it is adviseable that the stator coil be
monitored with thermal detection probes
(PTC or PT100).
• Performances
We guarantie that the performance of the
exchanger complies with the denitions
agreed upon. (ambiant temperature, power
to be evacuated, environmental conditions,
loss of charge etc.).
• Manufacture of the exchanger
The exchanger casing is made from steel
sheets. The network of tubes is generally
composed of aluminium alloy or steel
tubes. The ends of the tubes are tted to
steel panels.
• Exchanger maintenance
If the coolant is used in a clean atmosphere
it can run for several years with no
maintenance. If the atmosphere is polluted
(dust, sand, greasy vapours etc.) the tubes
must be cleaned regularly. Clogging of the
tubes becomes noticeable when the thermal
exchange performances are reduced and
the air in the primary circuit overheats
causing the machine to also overheat ;
therefore, machine overheating indicates
that the exchanger is probably dirty.

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
4.4 - Air/water heat exchanger:
LSA 49.1 IC8
• Description of the cooler
losses (mechanical, ohmic...). The exchan-
ger is located on the top of the machine.
Normal operation :
the air is pulsed by a fan xed to the
synchronous machine shaft. The air goes
through the exchanger, rendering its
calories.
AIR / WATER double tube exchanger:
The double-tube technique keeps the
cooling circuit from being a󰀨ected by
possible water leakage. The double tube
provides a high safety level. In case of
leakage, the water goes from the inside of
the internal tube to the coaxial space
between the two tubes. The water is drained
axially to a leakage chamber where it may
activate a sensor.
An exchanger is comprised of a n-tube
block containing:
- a steel frame,
- a n-tube block crimped mechanically to
the tubes.
The tube bundle is roll-expanded in the end
plates (parts 3 and 4).
The water distribution in the tubes is
provided by two removable water boxes
(part 5). A water box is equipped with collars
for tting the inlet and outlet lines. Neoprene
seals ensure the watertightness between
the water boxes and the end plates.
AIR / WATER single tube exchanger:
An exchanger is comprised of a n-tube
block containing :
- a steel frame,
- a n-tube block crimped mechanically onto
the tubes.
The tube bundle is roll-expanded in the end
plates.
The water distribution in the tubes is
provided by two removable water boxes.
One water box is equipped with collars for
tting the inlet and outlet water lines.
Neoprene seals provide watertightness
between the water boxes and the end plates.
• Maintenance of the water-cooler
The frequency of cleaning operations
depends essentially on the purity of the
water used. We recommend a minimum of
one inspection per year.
Stop the machine.
Cut o󰀨 the power supply by isolating the inlet
and outlet lines, and drain the water.
Disconnect the leak sensor (option with
double-tube cooler), and make sure that
there are no leaks.
Remove the water boxes on each side of the
machine.
Rinse and brush each water box.
Note : do not use a hard wire brush as this
will remove the protective oxidation layer
which has formed on the surfaces of the
water boxes.
Clean each tube with a metal scraper ; rinse
in soft water.
Keep the leakage chamber dry (double-tube
water-cooler only).
• Leak detection for a double-tube
exchanger
If a leak is detected, it is necessary to
ascertain its origin immediately and repair it.
Remove the two water boxes, apply a slight
positive pressure in the leakage chamber,
thus between the two tubes (only concerns
the double-tube coolers).
If a tube is damaged : plug it at BOTH ends.
Use a tapered plug.
The plug should preferably be made of salt-
water resistant aluminium bronze or of a
synthetic material.
1 - Single internal tube
2 - External tube with
internal grooving and
with external ns
3 - Internal plate
4 - External plate
5 - Outside wall of the
pressure tank
6 - Flow of water or
liquid leaks

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
• Servicing the water-cooler
Cooler removal:
The cooler unit is slid into the box caisson. It
is possible to remove the cooler from the
caisson without removing the water boxes.
The cooler is fastened to the caisson via a
series of screws on the water box.
Remove the supply and return pipes.
Provide two supports to hold the cooler
when it comes out of its housing.
Remove the cooler using slings that can be
attached to the connecting anges.
Cooler re-assembly:
Carry out the operations of the «Cooler
removal» chapter in the reverse order. Be
careful to push the cooler completely into its
housing before tightening the fastening
screws of the cooler to the caisson.
• Cooler protection devices (depending
on option)
Leak detection (oat system):
A magnet oat activate a switch located into
the oat guiding rod.
Leak detection (electrode system):
The REDOX 69 system measures the
apparent resistance of the uid whose
leakage is to be checked.
By apparent resistance is meant the
resistance between the electrodes of the
system when they are immersed in their
receptacle. The current which circulates is
used to activate a relay.
Contact Electrodes
submerged
Electrodes dry
Relay not excited
01-01 open closed
F1-F1 closed open
4.5 - Bearings
The bearings are greasable. It is advisable
to lubricate the machine during operation.
The lubrication characteristics are given in
the table below.
Bearings 6322/C3 6320/C3
Quantity of grease:
gr or cm350 60
Lubrication interval:
hours 4500 4500
Lubrication intervals are given for grease
type: LITHIUM - standard - NLGI 3
The factory lubrication is performed with
grease: ESSO UNIREX N3
Before using another grease, check for
compatibility with the original one. Monitor
the temperature rise in the bearings, which
should not exceed 60°C above the ambient
temperature. Should this value be exceeded,
the machine must be stopped and checks
carried out.
• Electrical servicing
Cleaning product for the windings
Do not use : trichlorethylene, perchlo-
rethylene, trichloroethane or any alkaline
products.
Certain strictly dened pure volatile
degreasing agents can be used, such as:
- Normal petrol (without additives);
inammable,
- Toluene (slightly toxic); inammable,
- Benzene (or benzine, toxic); inammable,
- Ciclohexare (non toxic); inammable.
WARNING
Detector dry
Guide rod
Magnetique oat
Blue
Brown
Black
Mains

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
Cleaning of the stator, rotor, exciter and
diode bridge
The insulating components and the
impregnation system are not at risk of
damage from solvents (see the above list of
authorised products).
Avoid letting the cleaning product run into
the slots. Apply the product with a brush,
sponging frequently to avoid accumulation
in the housing. Dry the winding with a dry
cloth. Let any traces evaporate before rea-
ssembling the machine.
• Mechanical servicing
Cleaning the machine using water or a
high-pressure washer is strictly prohi-
bited. Any problems arising from such
treatment are not covered by our
warranty.
The machine should be cleaned with a
degreasing agent, applied using a brush.
Check that the degreasing agent will not
a󰀨ect the paint. Compressed air should
used to remove any dust.
After cleaning the alternator, it is essential to
check the winding insulation (see sections
3.2 and 4.8).
4.6 - Fault detection
If, when commissioned, the alternator does
not work normally, the source of the
malfunction must be identied. To do this,
check that :
- the protective devices are tted correctly,
- the connections comply with diagrams in
the manuals supplied with the machine,
- the speed of the unit is correct (see
nameplate).
Repeat the operations dened in section 3.
WARNING
4.7 - Mechanical defects
Fault Action
Bearing
Excessive overheating of one or
both bearings
(bearing temperature 80°C above
the ambient temperature)
- If the bearing has turned blue or if the grease has turned
black, change the bearing
- Bearing not fully locked (abnormal play in the bearing cage)
- End shields incorrectly aligned
Abnormal
temperature
Excessive overheating of
alternator frame (more than
40° C above the ambient
temperature)
- Air ow (inlet-outlet) partially clogged or hot air is being
recycled from the alternator or engine
- Alternator operating at too high a voltage (>105% of Un on
load)
- Alternator overloaded
Vibrations
Too much vibration
- Misalignment (coupling)
- Defective mounting or play in coupling
- Rotor balancing fault (Engine - Alternator)
Excessive vibration and humming
noise coming from the machine
- Phase imbalance
- Stator short-circuit
Abnormal
noise
Alternator damaged by a
signicant impact, followed by
humming and vibration
- System short-circuit
- Misparalleling
Possible consequences
- Broken or damaged coupling
- Broken or bent shaft end
- Shifting and short-circuit of main eld
- Fan fractured or coming loose on shaft
- Irreparable damage to rotating diodes/AVR, surge suppressor

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Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
4.8 - Electrical faults
Fault Action Effect Check/Cause
No voltage
at no load on
start-up
Connect a new
battery of 4 to 12
volts to terminals
E- and E+,
respecting the
polarity, for 2 to 3
seconds
The alternator builds up and
its voltage is still correct
when the battery is removed
- Lack of residual magnetism
The alternator builds up but
its voltage does not reach
the rated value when the
battery is removed
- Check the connection of the voltage
reference to the AVR
- Faulty diodes
- Armature short-circuit
The alternator builds up but
its voltage disappears when
the battery is removed
- Faulty AVR
- Field windings open circuit (check winding)
- Revolving eld coil open circuit (check the
resistance)
Voltage too
low
Check the drive
speed
Correct speed
Check the AVR connections (AVR may be
faulty)
- Field windings short-circuited
- Rotating diodes burnt out
- Revolving eld coil short-circuited (check the
resistance)
Speed too low
Increase the drive speed (do not touch the AVR
voltage pot. (P2) before running at the correct
speed)
Voltage too
high
Adjust AVR
voltage
potentiometer
Adjustment ineffective - Faulty AVR
- 1 faulty diode
Voltage
oscillations
Adjust AVR
stability
potentiometer
If no effect: try normal or fast
stability modes (ST2)
- Check the speed : possibility of cyclic
irregularity
- Loose connections
- Faulty AVR
- Speed too low when on load (or LAM set too
high)
Voltage
correct
at no load
and too low
when on load
Run at no load
and check the
voltage between
E+ and E- on the
AVR
Voltage between E+ and E-
AREP / PMG < 10V - Check the speed (or LAM set too high)
Voltage between E+ and E-
AREP / PMG > 15V
- Faulty rotating diodes
- Short-circuit in the revolving eld coil (check
the resistance)
- Faulty exciter armature (check the resistance)
Voltage
disappears
during
operation
Check the AVR,
the surge
suppressor, the
rotating diodes,
and replace any
defective
components
The voltage does not return
to the rated value
- Exciter winding open circuit
- Faulty exciter armature
- Faulty AVR
- Revolving eld coil open circuit or short-
circuited

2022.02 / i
16
Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
• Checking the winding
You can check the winding insulation by
performing a high voltage test. In this case,
you must disconnect all AVR wires.
WARNING
Damage caused to the AVR in such
conditions is not covered by our
warranty.
• Checking the windings and rotating
diodes using separate excitation
During this procedure, make sure that
the alternator is disconnected from any
external load and inspect the terminal
box to check that the connections are
fully tightened.
1) Stop the unit, disconnect and isolate the
AVR wires.
2) There are two ways of creating an
assembly with separate excitation.
Assembly A: Connect a 12 V battery in
series with a rheostat of approximately
50 ohms - 300 W and a diode on both exciter
eld wires (5+) and (6-).
6 - 5 +
1A diode
12V battery
Rh. 50 -300W
-
+
A
SSEMBLY A
Field
Assembly B: Connect a “Variac” variable
power supply and a diode bridge on both
exciter eld wires (5+) and (6-).
Both these systems should have
characteristics which are compatible with
the eld excitation power of the machine
(see the nameplate).
3) Run the unit at its rated speed.
4) Gradually increase the exciter eld
current by adjusting the rheostat or the
variac and measure the output voltages on
L1 - L2 - L3, checking the excitation voltage
and current at no load (see the machine
nameplate or ask for the factory test report).
When the output voltage is at its rated value
and balanced within 1% for the rated
excitation level, the machine is in good
working order. The fault therefore comes
from the AVR or its associated wiring (ie.
sensing, auxiliary windings).
1A diode
-
+
6 - 5 +
Variac AC
220V
DC
12V
50
60
70
80
90
100
40
30
20
10
0
ASSEMBLY BField
• Checking the diode bridge
A diode in good working order should allow
the current to ow only in the anode-to-
cathode direction.
C
A
- -
+ +
~ ~ ~
C C C
A A A
C C C
A A A
~ ~ ~
-
C
A
+
-
C
A
+
Anode Cathode

2022.02 / i
17
Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
4.9 - Dismantling, reassembly
During the warranty period, this
operation should only be carried out in
an approved workshop or in our factory,
otherwise the warranty may be
invalidated.
Whilst being handled, the machine
should remain horizontal.
• Tools required
To fully dismantle the machine, we
recommend using the tools listed below:
- 1 ratchet spanner + extension
- 1 torque wrench
- 1 set of at spanners : 9 mm, 10 mm, 18 mm
- 1 socket set : 10, 13, 17, 18, 19, 24 mm,
- 1 puller (U35) / (U32/350)
- 1 hexagonal wrench 6 mm - 10 mm
• Screw tightening torque
IDENTIFICATION screw Ø Torque N.m
Exciter screw M6 8.3
Diode / Star bridge M6 10
Diode nut M6 3
DE shield / frame screw M12 70
NDE shield / frame screw M12 70
Bush / casing M12 70
Earth screw M12 35
Grille screws M6 4
Cover screws M6 5
Stator connection nut M12 35
• Access to diodes
- Remove the diodes access door (140).
- Disconnect the diodes.
- Check the diodes using an ohmmeter or a
battery lamp.
If the diodes are faulty:
- Remove the surge suppressor (347).
- Remove the «H» nuts for mounting the
diode assembly on the support.
- Change the crescents, respecting the
polarity.
• Access to connections and the
regulation system
Access is directly after removing the terminal
box cover (132).
• Replacing the NDE bearing
- Remove the terminal box cover (132).
- Unplug (+ et -) exciter eld.
- If bearing probe, unplug at the terminal,
break the network circlips up to the bearing.
On LSA 49.1 IC6:
- Dismantle the air intake grille (51).
- Dismantle the secondary circuit turbine
(118).
- Dismantle the air ventilation casing (117).
- Remove the NDE «O» ring (249).
On LSA 49.1 IC8:
- Remove sealing cap (53).
- Remove the inner bearing retainer screws
(78).
- Remove the NDE ange (82).
- Take out the antifriction bearing (70) using
a puller with a central screw (see drawing
below).
- Change the «O» ring seal (349).
- Fit the new antifriction bearing after heating
it by induction to approximately 80 °C.
WARNING
Replace the dismantled bearing with a
new one.
• Replacing the DE bearing
- If bearing probe, unplug at the terminal,
break the network clips up to the bearing.
- Remove the DE «O» ring (247).
- Remove the inner bearing retainer screws
(68).
WARNING

2022.02 / i
18
Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
- Remove the DE ange (410).
- Take out the circlips (284).
- Take out the antifriction bearing (60) using
a puller with a central screw.
- Fit the new antifriction bearing after heating
it by induction to approximately 80 °C.
WARNING
Replace the dismantled bearing with a
new one.
• Dismantling the assembly
- Take out the NDE bracket (36) following the
instructions in section above.
- Take out the DE bracket (30) following the
instructions in section above.
- Remove the diodes access doors (140).
- Remove the grease nipple tubes (77).
- Dismantle the air tube casing (116) on LSA
49.1 IC6 or exchanger (11h + 11s LSA 49.1
IC8).
- Remove the DE bracket (30).
- Support the DE rotor (4) with a strap or with
a support.
- Using a mallet gently hit the end of the shaft
on the DE opposite side.
- Move the strap as the rotor moves in order
to distribute the weight over it.
• Reassembling the assembly
- Place the «O» ring seal (349) and the
preloading (wavy) washer (79) in the NDE
bracket (36).
- Mount and x the ange (82) on the NDE
bracket (36).
- Mount the rotor (4) in the stator (1).
- Mount and x the DE bracket (30).
- Ret the air tube casing (116).
- Ret the front and rear grease nipple tubes
(77) in the inner bearing retainers.
- Ret the diodes access doors (140).
- Ret and x the DE ange (410).
- Fix the inner bearing retainer (68).
- Ret the DE «O» ring (247).
- Ret the NDE «O» ring (249).
- Ret the air ventilation casing (117).
- Ret the secondary circuit turbine (118).
- Ret the air intake grille (51).
- Reconnect the exciter eld and close the
terminal box cover.
4.10 - Table of characteristics
Table of average values:
Alternator - 4 poles - 50 Hz - Standard
winding No. 6S (6-wire) (400V for the
excitation values).
The voltage and current values are given for
no-load operation and operation at rated
load with separate eld excitation.
All values are given at ± 10% and may be
changed without prior notication (for exact
values, consult the test report).
• Resistances of main windings
at 20°C (Ω)
Average values for 6S winding (6-wire)
Type Stator L/N Rotor Exciter
eld
Exciter
armature
L6 0.0029 0.38 12 0.08
L9 0.0021 0.43 12 0.08
• Field excitation current i exc (A)
Type No load At rated load
L6 0.5 2.2
L9 0.9 2.2
For 60 Hz machines, the “i exc” values are
approximately 5 to 10 % lower.

2022.02 / i
19
Electric Power Generation Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
5 - SPARE PARTS
5.1 - First maintenance parts
Emergency repair kits are available as an
option.
They contain the following items :
Emergency kit AREP ALT 491 KS 001
AVR R450 -
Diode bridge assembly -
Surge suppressor -
Single-bearing kit ALT 491 KB 002
Non drive end bearing -
«O» ring -
Preloading (wavy) washer -
Double-bearing kit ALT 491 KB 001
Non drive end bearing -
Drive end bearing -
«O» ring -
Preloading (wavy) washer -
5.2 - Technical support service
Our technical support service will be
pleased to provide any additional
information you may require.
For all spare parts orders or technical
support requests, send your request to
[e-mail] or your
nearest contact, whom you will nd at
www.lrsm.co/support indicating the comp-
lete type of machine, its number and the
information indicated on the nameplate.
Part numbers should be identied from the
exploded views and their description from
the parts list.
To ensure that our products operate correctly
and safely, we recommend the use of
original manufacturer spare parts.
In the event of failure to comply with this
advice, the manufacturer cannot be held
responsible for any damage.
After operational testing, it is essential to
replace all access panels or covers.

2022.02 / i
20
Electric Power Generation
78 70
90
1
4
132
51
30
128
284 68
15
28
22
349
343
107
100
140
140
347
60
77
410
82
77
28
36
118 117
120
172
116
79
18
247
249
Installation and maintenance
LSA 49.1 IC6 / LSA 49.1 IC8
Low Voltage Alternators - 4 pole
4528 en -
5.3 - Air/air heat exchanger exploded view: LSA 49.1 IC6