17
INSTALLATION AND MAINTENANCE
LSA 46.2 / 47.1 - 4 POLE
ALTERNATORS
SERVICING - MAINTENANCE
Ref. 2981 GB - 4.33/b - 07.02
LEROY-SOMER
4.5.3 - 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
field wires (5+) and (6-).
Assembly B
: Connect a “Variac” variable power supply and
a diode bridge on both exciter field wires (5+) and (6-).
Both these systems should have characteristics which are
compatible with the machine field excitation power (see the
nameplate).
3) Run the unit at its rated speed.
4) Gradually increase the exciter field 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 and on 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).
4.6 - Dismantling, reassembly
(see sections 5.4.1. & 5.4.2.)
During the warranty period, this operation should
only be carried out in an approved LEROY-SOMER
workshop or in our factory, otherwise the warranty
may be invalidated.
Whilst being handled, the machine should remain
horizontal (rotor not locked when moved).
4.6.1 - Tools required
To fully dismantle the machine, we recommend using the
tools listed below :
- 1 ratchet s extension,
- 1 torque wrench,
- 1 set of flat spanners : 8 mm, 10 mm, 18 mm,
- 1 socket set : 8, 10, 13, 16, 18, 21, 24, 30 mm
- 1 socket with male ferrule : 5 mm,
- 1 puller.
4.6.2 - Screw tightening torque
6 -
5 +
Diode 1A
12V battery
Rh. 50
Ω
-300W
-
+
ASSEMBLY A
Exciter field
Diode 1A
-
+
6 -
5 +
Variac
AC
220V
DC
12V
50
60
70
80
90
100
40
30
20
10
0
ASSEMBLY B
Exciter field
IDENTIFICATION
Screw Ø Torque
N.m
Exciter screw
M 6
10
Star diode bridge
M 6
10
Diode nut
M 6
4
Flange / Frame screw (46.2 S,
M)
M 14
80
Flange / Frame screw (46.2 L,
VL)
M 14
190
Flange / Frame screw (47.1)
M 16
190
NDE bracket / frame screw
M 12
50
Discs / Sleeve screw
M 16
230
Earth screw
M 10
20
Grille screws
M 6
5
Cover screws
M 6
5
Terminal block nut
M 12
35
WARNING
ARNING
