Leroy-Somer LSA 42.3 Instruction Manual

LSA 42.3
Low Voltage Alternator - 4 pole
Installation and maintenance

2021.06 / o
2
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 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.
Warningsymbolforanoperationcapable
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 42.3
Low Voltage Alternator - 4 pole
4803 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
3 - INSTALLATION .................................................................................................................7
3.1 - Assembly ................................................................................................................... 7
3.2 - Checks prior to rst use.............................................................................................8
3.3 - Terminal connection diagrams...................................................................................8
3.4 - Commissioning ........................................................................................................ 11
3.5 - Setting up ................................................................................................................ 11
4 - SERVICING - MAINTENANCE........................................................................................12
4.1 - Safety measures......................................................................................................12
4.2 - Routine maintenance...............................................................................................12
4.3 - Bearings ..................................................................................................................13
4.4 - Mechanical defects..................................................................................................13
4.5 - Electrical faults ........................................................................................................ 14
4.6 - Dismantling, reassembly .........................................................................................16
4.7 - Installation & maintenance of the PMG ................................................................... 18
4.8 - Table of characteristics ............................................................................................18
5 - SPARE PARTS ................................................................................................................20
5.1 - First maintenance parts ...........................................................................................20
5.2 - Technical support service ........................................................................................20
5.3 - Exploded views, parts list and tightening torque .....................................................21
Disposal and recycling instructions
EC Declaration of compliance and incorporation

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Electric Power Generation
Model
S/N
Enclosure
Th. Class
Weight
AVR
Date
Protection
Altitude
PF
Excitation
Freq.
Speed
Voltage
Phase
V
min
-1
Hz
kVA
kW
A
kVA
kW
A
Connection
Cont.
BR
40°C
Std by.
PR
27°C
Made in Europe by Leroy-Somer
IEC 60034 - 1& 5
ISO 8528 - 3
NEMA MG1 - 32 & 33
MOTEURS LEROY-SOMER
2 BD MARCELLIN LEROY - 16000 ANGOULÊME - FRANCE
Excitation
415 v / 40°C
DE bearing
NDE bearing
No Load Full Load
www.leroy-somer.com
LSA 000-1-148 a
Scan the code or go to
GEN.LS1.DO
to check product data
12345678910
LSA
Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 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 42.3
Low Voltage Alternator - 4 pole
4803 en -
2 - TECHNICAL
CHARACTERISTICS
2.1 - Electrical characteristics
This alternator is a machine without
sliprings or revolving armature brushes,
wound as “2/3 pitch”, 4 or 12-wire, with
class H insulation and a eld excitation
system available in either SHUNT, AREP or
PMG version (see diagrams and AVR
manuals).
• Electrical options
- Stator temperature detection sensors
- Space heaters
- R791 interference suppression
2.2 - Mechanical characteristics
- Steel frame
- Aluminum end shields
- Protected ball bearings, greased for life
- Mounting arrangement: single bearing
with standard feet and SAE anges/
coupling discs, two-bearing with SAE ange
and standard cylindrical shaft extension
- Drip -proof machine, self-cooled
- Degree of protection: IP 23
• Mechanical options
- Direct output power by cables (not
reconnectable), regulator tted outside the
alternator
- Protection against harsh environments
- Air inlet lter, air outlet lter
Alternators tted with air inlet lters are
subject to a power derating of 5%.
To prevent excessive temperature rise
caused by clogged lters, it is advisable to t
the stator winding with thermal sensors
(PTC).
• SHUNT dedicated single-phase 4-wire
Varistor
R221
T1
T2
T3
T4
STATOR: 4-wire (marking T1 to T4)
MAIN FIELD
Power supply /
Detection
EXCITER
Field
Armature

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
T1 T2 T3
T4 T5 T6
VaristorVaristor
Varistor
5+ 6-
T7 T8 T9
T10 T11 T12
T1 T2 T3
T4 T5 T6
5+ 6-
T7 T8 T9
T10 T11 T12
T1 T2 T3
T4 T5 T6
5+ 6-
T7 T8 T9
T10 T11 T12
PMG
R220
D350
D350
STATOR: 12-wire (marking T1 to T12)
STATOR: 12-wire (marking T1 to T12)
STATOR: 12-wire (marking T1 to T12)
MAIN FIELD
Power supply / Detection
Auxiliary windings
MAIN FIELD
Voltage reference
MAIN FIELD
Voltage reference
EXCITER
Field
Armature
EXCITER
Field
Armature
EXCITER
Field
Armature
• SHUNT three-phase 12-wire
• AREP three-phase 12-wire
• PMG three-phase 12-wire

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
3 - INSTALLATION
Personnel undertaking the various
operations indicated in this section must
wear personal protective equipment
appropriateformechanicalandelectrical
hazards.
3.1 - Assembly
All mechanical handling operations
must be undertaken using suitable
equipment and the machine must be
horizontal.Checkhowmuchthe machine
weighs before choosing the lifting tool.
During this operation, do not allow
anyone to stand under the load.
• Handling
The generously-sized lifting eyes are for
handling the alternator only. They must not
be used to lift the genset. The choice of
liftinghooksorhandlesshouldbedetermined
by the shape of the lifting eyes. Choose a
lifting system which respects the integrity
and the environment of the machine.
During this operation, do not allow
anyone to stand under the load.
• Single-bearing coupling
Before coupling, check the compatibility
between the alternator and the engine by
performing:
- undertaking a torsional analysis of the
transmission (alternators data are available
on request),
- checking the dimensions of the ywheel
and its housing, the ange, coupling discs
and o󰀨set.
WARNING
When coupling the alternator to the
prime mover, do not use the fan to turn
the alternator or rotor.
The holes of the coupling discs should
be aligned with the ywheel holes by
cranking the engine.
Make sure the machine is securely
bedded in position during coupling.
Check that there is lateral play on the
crankshaft.
• 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 location where the alternator is placed
must be ventilated to ensure that the
ambient temperature cannot exceed the
data on the nameplate.
After handling the machine using the
lifting ring, snap on the plastic cover
provided in the maintenance manual
wallet.
WARNING

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
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 bolts are tight,
- the length of bolt and the tightening torque
are correct,
- the cooling air is drawn in freely,
- the protective grille and housing are cor-
rectly in place,
- the standard direction of rotation is clock-
wise as seen from the drive 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).
3.3 - Terminal connection diagrams
To modify the connection, change the
position of the stator cables on the terminals.
The winding code is specied on the
nameplate.
Any intervention on the alternator
terminals during reconnection or checks
should be performed with the machine
stopped. In no case should the internal
connections in the terminal box be
subjected to stresses due to cables
connected by the user.
WARNING
When the alternator’s power output is
ensured directly through cables, these
must be connected before start-up.
• SHUNT dedicated single-phase 4-wire
T1 T2 T3 T4
T3 T4
T1 T2
T4
T1
T2
T3
110V
0V
L
L
M
T2
T3
T4
T1
L
L
110V
0V
R221R221
Connection
Series connection
Parallel connection
DE
NDE
DE
NDE

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
• SHUNT, AREP or PMG three-phase 12-wire
6
7
8
6
7
8
60 Hz50 Hz
220 - 240 220 - 240
-
60 Hz50 Hz
220 - 240 220 - 240
-
L
T1 T7
T12
T10
T4
T9
T3
T6
T11
T5
T2 T8
L
M
6
7
8
L1(U)
M
L3(W)
T1
T7
T12
T10
T4
T9
T3
T6
T11 T5 T2
T8
L2(V)
LL
T1
T7
T12
T10
T4
T9
T3 T6
T11 T5
T2
T8
L1(U)
L3(W) L2(V)
60 Hz50 Hz
380 - 415 380 - 480
440 - 460
250 - 260
220 - 240
200
250 - 260
220 - 240
200
-
-380 - 416
D
3PH
FF
1PH
F
L1(U)
N
L3(W)
T1 T7
T12
T10
T4
T9
T3
T6
T11
T5
T2
T8
L2(V)
A
3PH
60 Hz50 Hz
190 - 208
220 - 230
190 - 240
-
-
190 - 208
6
7
8
1PH
3PH
R220 :
0 => (T8) / 110 V => (T11)
D350 :
U => T1 / V => T2 / W => T3
R220 :
0 => (T8) / 110 V => (T11)
D350 :
U => T1 / V => T2 / W => T3
R220 :
0 => (T8) / 110 V => (T11)
D350 :
U => T1 / V => T2 / W => T3
R220 :
0 => (T1) / 110 V => (T4)
D350 :
V => T1 / W => T10
N
N
L1(U)
L2(V)
L3(W)
T9
T8
T7
T12
T10
T11
T4
T3
T2
T1
T5 T6
N
L1(U)
L2(V)
L3(W)
T9
T8
T7
T12
T10
T11
T4
T3
T2
T1
T5
T6
L1(U)
L2(V)
L3(W)
L
L
T9
T8
T7 T12
T10
T11
T4
T3
T2
T1
T5
T6
M
L
L
T9
T8
T7
T12
T10
T11 T4
T3
T2
T1
T5
T6
or
Connection codes Voltage / Detection Factory connection
Voltage LM = 1/2 voltage LL
Voltage LM = 1/2 voltage LL
Winding
Winding
In case of reconnection, ensure that AVR voltage detection is correct!
Winding
NDE
NDE
NDE
Winding
NDE

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
• SHUNT, AREP or PMG three-phase 12-wire
B60 Hz50 Hz
110 - 120
120 - 130
120
-
-
110 - 120
6
7
8
R220 :
0 => (T8) / 110 V => (T11)
D350 :
U => T1 / V => T2 / W => T3
G1PH 60 Hz50 Hz
220 - 240
250 - 260
220 - 240
200
-
220 - 240
6
7
8
R220 :
0 => (T8) / 110 V => (T11)
D350 :
V => T2 / W => T3
M
T1
T7
T12
T10
T4
T9
T3
T6
T11
T5
T2
T8
L
L
R221 : 0 => (T1) / 110 V => (T2)R221 : 0 => (T1) / 110 V => (T2)
1PH
3PH
LL
L3(W)
T1
T7
T10
T9 T3
T6
T11
T5 T2
T8
L2(V)
T12
T4
L1(V)
L1(U)
L2(V)
L3(W)
L
L
T9
T8
T7
T12
T10
T11
T4
T3
T2
T1
T5
T6
M
L
L
T9
T8
T7
T12
T10
T11
T4
T3
T2
T1
T5
T6
T1 T4
T3
T2
L L
M
L - L
220
230
240
110
115
120
T2 - T3 T2 - T3T1 T4
L - M L L M
T1
T4
T3
T2
LL
L - L
-
-
-
110
115
120
T1 - T3
T2 - T4 -T1-T3 T2 - T4
L - M L L M
Connection codes Voltage / Detection Factory connection
Winding
NDE
Voltage LM = 1/2 voltage LL
Winding
NDE
Series
connection
Parallel
connection
SINGLE-PHASE 4-WIRE - DEDICATED WINDING type M or M1
Voltage 50/60Hz Voltage 50/60Hz
LinkLink
OutputOutput
or
• Option connection diagram
ST
Ph1
Ph2
Ph3
101
102
103
104
5
0
10
2 0
3 0
4 0
50
60
7 0
8 0
9 0
Voltage adjustment
via remote potentiometer
Remote voltage potentiometer
Anti condensation heater Thermistor temperature (PTC)
130 °C
Blue wire
150 °C
Black wire
180 °C
Red/white wire

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 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%
3.4 - 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 4.3).
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 3.5). If
the machine still operates incorrectly, the
cause of the malfunction must be located
(see section 4.5).
3.5 - 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.
TheAVRisusedtomake anyadjustments
to the machine.

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 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
appropriateformechanicalandelectrical
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 bolts on the machine are
still tight, plus the general state of the
machine and the various electrical
connections in the installation.
• Electrical servicing
Commercially-available volatile degreasing
agents can be used.
Do not use: trichlorethylene, perchlo-
rethylene,trichloroethaneoranyalkaline
products.
These operations must be performed at a
cleaning station, equipped with a
vacuum system that collects and ushes
out the products used.
The insulating components and the
impregnation system are not at risk of
damage from solvents. 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 reassembling
the machine.
• Mechanical servicing
Cleaning the machine using water or a
highpressure washer is strictly prohi-
bited. Any problems arising from such
treatment are not covered by our
warranty.
Degreasing: Use a brush and detergent
(suitable for paintwork).
Dusting: Use an air gun.
If the machine is tted with air inlet and outlet
lters, the maintenance personnel should
clean them routinely at regular intervals. In
the case of dry dust, the lter can be cleaned
using compressed air and/or replaced if it is
clogged.
After cleaning the alternator, it is essential to
check the winding insulation (see sections
3.2 and 4.5).
WARNING
WARNING

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Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
4.3 - Bearings
The bearings are permanently greased Approximate life of the grease (depending on use) =
20,000 hours or 3 years.
4.4 - 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 42.3
Low Voltage Alternator - 4 pole
4803 en -
4.5 - 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
Voltage
oscillations
Adjust the
AVR stability
potentiometer
- Check the speed: possibility of cyclic
irregularity
- Loose connections
- Faulty AVR
- Speed too low when on load (or AVR 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
AREP/PMG : Voltage
between E+ and E– =
6V < UDC < 10V
- Check the speed (or AVR LAM set too high)
SHUNT : Voltage between
E+ and E– =
10V < UDC < 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
(*) During single-phase operation, check that the sensing wires from the AVR are connected to the correct output terminals.

2021.06 / o
15
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 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.
+-
+R
-W
IN
IN
-W
+R
IN IN
Anode Cathode

2021.06 / o
16
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
4.6 - 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 (rotor not
locked in position). Check how much the
machine weighs before choosing the
lifting method.
• 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: 8 mm, 10 mm, 12 mm
- 1 socket set: 8, 10, 13 mm
- 1 socket TORX bit T20 and T30
- 1 puller (eg. Facom: U35, U32/350)
• Screw tightening torque
See section 5.3.
The screws for xing the feet on the
housing and immobilising the stator
must not be removed (screw of the stator
lower).
• Access to connections and the
regulation system
The terminals are accessed directly by
removing the terminal box panel (41).
AVR is accessed directly by the access
panel (59) of terminal box.
• Accessing, checking and replacing the
diode bridge
Dismantling
- Remove the terminal box panel (41).
- Cut the xing clamps of the exciter cables,
disconnect E+, E- from the exciter.
- Remove the nuts on the tie rods.
- Remove the NDE shield (36) using a puller:
eg. U.32 - 350 (Facom).
- Unsolder the connections.
- Check the bridge using an ohmmeter or a
battery lamp.
Reassembly
- Replace the bridges, respecting the
polarity.
- Resolder the connections.
- Ret the NDE shield and pass the bundle
of wires between the top bars of the shield.
- Replace the xing clamps on the cables.
- Replace the terminal box panel (41).
WARNING
Rotor
NDE shield
Threaded rod M10

2021.06 / o
17
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
• Replacing the NDE bearing on single
bearing machines
Dismantling
- Remove the NDE shield (36).
- Remove the ball bearing (70) using a screw
puller.
Reassembly
- Heat the inner slipring of a new bearing by
induction or in a drying oven at 80 °C (do not
use an oil bath) and t it to the alternator.
- Place the preloading wavy washer (79) in
the shield.
- Replace the NDE shield (36).
• Replacing the bearings on two-bearing
machine
Dismantling
- Uncouple the alternator from the prime
mover.
- Remove the assembly screws.
- Remove the DE shield (30).
- Remove the NDE shield.
- Remove both antifriction bearings (60) and
(70) using a puller with a central screw.
Reassembly
- Heat the new bearings by induction or in a
drying oven at 80°C (do not use an oil-bath)
and t them to the machine.
- Check that both the preloading wavy
washer (79) have been tted on the NDE
shield (36).
- Ret the DE shield (30) and tighten the
xing screws.
- Check that the alternator assembly is
correctly mounted and that all screws are
tightened.
• Accessing the main eld and stator
Dismantling
Follow the procedure for dismantling
bearings.
- Remove the coupling discs (single-bearing
alternator) or the DE shield (two-bearing
alternator) and insert a tube of the
corresponding diameter on the shaft end or
a support made according the following
bellow.
- Rest the rotor on one of its poles, then slide
it out. Use the tube as a lever arm to assist
dismantling.
- After extracting the rotor, be careful not to
damage the fan and place the revolving eld
on special V-blocks.
NOTE: If intervention is required on the
main eld (rewinding, replacement of
components), the rotor assembly must
be rebalanced.
Reassembling the revolving eld coil
- Follow the dismantling procedure in
reverse order.
Take care not to knock the windings when
retting the rotor in the stator.
If you replace the fan, respect the assembly
guide according the following bellow. Use a
tube and a screw.

2021.06 / o
18
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
Follow the procedure for reassembling the
bearings.
4.7 - Installation and maintenance of
the PMG
The PMG reference is PMG 0.
See the PMG manual ref : 4211.
4.8 - Table of characteristics
Table of average values:
Alternator - 4 pole - 50 Hz - Standard winding
No. 6 (12-wire) and M or M1 (4-wire)
connected in dedicated single-phase (400 V
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 to within ± 10% and may
be changed without prior notication (for
exact values, consult the test report).
For 60 Hz machines, the “i exc” values are
approximately 5 to 10 % lower.
• Three-phase: 4-pole, SHUNT excitation
Resistances at 20 °C (Ω)
Type Stator
L/N Rotor Exciter eld
Exciter
armature
VS1 0.277 0.60 17.6 0.19
VS2 0.261 0.62 17.6 0.19
VS3 0.213 0.67 17.6 0.19
S4/S5 0.151 0.78 17.6 0.19
M7 0.135 0.84 17.6 0.19
M8 0.114 0.87 17.6 0.19
L9 0.091 0.95 17.6 0.19
Field excitation current i exc (A)
400V - 50 Hz
“i exc”: excitation current of the exciter eld
Type No load At rated load
VS1 0.55 1.77
VS2 0.52 1.75
VS3 0.51 1.8
S4 0.49 1.55
S5 0.49 1.76
M7 0.46 1.77
M8 0.5 1.9
L9 0.5 2.07
• Three-phase: 4-pole, AREP excitation
Resistances at 20 °C (Ω)
Type Stator
L/N Rotor Exciter eld
Exciter
armature
VS1 0.277 0.60 7.36 0.19
VS2 0.261 0.62 7.36 0.19
VS3 0.213 0.67 7.36 0.19
S4/S5 0.151 0.78 7.36 0.19
M7 0.135 0.84 7.36 0.19
M8 0.114 0.87 7.36 0.19
L9 0.091 0.95 7.36 0.19
Resistance of auxiliary windings at
20 °C (Ω)
Type X1, X2 Z1, Z2
VS1 0.402 0.454
VS2 0.398 0.475
VS3 0.402 0.517
S4/S5 0.334 0.458
M7 0.307 0.426
M8 0.319 0.447
L9 0.313 0.433

2021.06 / o
19
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
Field excitation current i exc (A)
400V - 50 Hz
“i exc”: excitation current of the exciter eld
Type No load At rated load
VS1 0.85 2.72
VS2 0.8 2.68
VS3 0.79 2.76
S4 0.75 2.38
S5 0.75 2.7
M7 0.71 2.71
M8 0.78 2.91
L9 0.77 3.18
• Dedicated single-phase M: 4-pole,
SHUNT excitation - 50 Hz
Resistances at 20 °C (Ω)
Type Stator
L/N Rotor Exciter eld
Exciter
armature
VS1 0.068 0.60 17.6 0.19
VS2 0.062 0.62 17.6 0.19
VS3 0.051 0.67 17.6 0.19
S4/S5 0.036 0.78 17.6 0.19
M7 0.032 0.84 17.6 0.19
M8 0.027 0.87 17.6 0.19
L9 0.023 0.95 17.6 0.19
Field excitation current i exc (A)
230V - 50 Hz
“i exc”: excitation current of the exciter eld
Type No load At rated load
VS1 0.55 1.31
VS2 0.52 1.31
VS3 0.51 1.22
S4 0.48 1.03
S5 0.48 1.16
M7 0.46 1.15
M8 0.50 1.21
L9 0.50 1.29
• Dedicated single-phase M1: 4-pole,
SHUNT excitation - 60 Hz
Resistances at 20 °C (Ω)
Type Stator
L/N Rotor Exciter eld
Exciter
armature
VS1 0.052 0.60 17.6 0.19
VS2 0.048 0.62 17.6 0.19
VS3 0.038 0.67 17.6 0.19
S4/S5 0.030 0.78 17.6 0.19
M7 0.026 0.84 17.6 0.19
M8 0.022 0.87 17.6 0.19
L9 0.018 0.95 17.6 0.19
Field excitation current i exc (A)
240V - 60 Hz
“i exc”: excitation current of the exciter eld
Type No load At rated load
VS1 0.52 1.26
VS2 0.51 1.31
VS3 0.52 1.26
S4 0.44 1.05
S5 0.44 1.20
M7 0.43 1.19
M8 0.47 1.28
L9 0.49 1.30
• Table of weights
(values given for information only)
Type Total weight (kg) Rotor (kg)
VS1 129 47
VS2 134 49
VS3 145 53
S4 170 63
S5 170 63
M7 185 69
M8 190 72
L9 207 79
After operational testing, it is essential to
replace all access panels or covers.

2021.06 / o
20
Electric Power Generation Installation and maintenance
LSA 42.3
Low Voltage Alternator - 4 pole
4803 en -
5 - SPARE PARTS
5.1 - First maintenance parts
Emergency repair kits are available as an
option.
They contain the following items:
Emergency kit SHUNT ALT 423 KS 001
AVR R220 -
Diode bridge assembly -
Surge suppressor -
Emergency kit AREP/PMG 5155833
AVR D350 -
Diode bridge assembly -
Surge suppressor -
Single-bearing kit ALT 423 KB 001
Non drive end bearing -
«O» ring -
Preloading (wavy) washer -
Double-bearing kit ALT 423 KB 002
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.