Troubleshooting; Checking The Windings And Rotating Diodes Using A Separate Excitation; Static Checking Of The Regulator - Leroy-Somer R452 Installation And Maintenance Manual

LEROY-SOMER

5 - TROUBLESHOOTING

5.1 - checking the windings and
rotating diodes using a 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.
- Stop the generator, disconnect and isolate the regulator
wires.
- There are two ways of creating an assembly with separate
excitation: see the diagrams below.
- Assembly A: Connect the DC supply (2 batteries in series)
in series with a rheostat of approximately 20 ohms 500W and
a diode on both exciter field wires (5+) and (6-).
ASSEMBLY A
Exciter field
6 -
5 A diode
-
Battery 12V
- Assembly B: Connect a "variac" variable power supply and
a diode bridge to both exciter field wires (5+) and (6-).
Both these systems must be compatible with the excitation
rating of the machine (see the nameplate).
- Run the generator set at its rated speed.
- Gradually increase the exciter field power supply current by
adjusting the rheostat or the variac and measure the output
voltages L1 - L2 - L3, monitoring the no-load excitation
voltages and currents. (See the alternator nameplate or ask
Leroy-Somer for the test log).
- If the output voltages are at their rated values and matched
to within < 1% for the given excitation value, the machine is
operating correctly and the fault is due to the regulation part
(regulator, wiring, sensing, auxiliary windings).
INSTALLATION AND MAINTENANCE
VOLTAGE REGULATOR R452
T
5 +
Rh. 20 Ω - 500 W
+
ROUBLESHOOTING
Variac

5.2 - static checking of the regulator

If the regulator operates correctly during a static test, this
does not necessarily mean that it will operate correctly under
real conditions.
If the regulator fails the static test, it can be concluded without
doubt that the regulator is faulty.
Connect a test bulb in accordance with the diagram.
The power supply voltage must be between 200 and 240V.
The bulb voltage is 220V. The bulb power rating must be less
than 100W.
- Turn potentiometer P1 fully anti-clockwise.
- Switch on the regulator; the bulb should light up briefly and
then go out.
- Slowly turn the voltage potentiometer clockwise, to the right.
- When turned fully to the right, the bulb lights up
continuously.
- At the regulation point, turning the voltage adjustment
potentiometer slightly in one director or the other should make
the bulb light up or go out. If the bulb is either lit continuously
or does not light up at all, the regulator is faulty.
- Perform one test supplying the regulator via terminals X1,
X2 then another supplying it via terminals Z1, Z2.
Static checking of the LAM:
P2 should be positioned at the point where the bulb lights up.
Turn the P4 potentiometer slowly to the left. The bulb should
dim suddenly and the voltage drops to approximately 85% of
the power supply voltage. Return to the P4 starting position.
The bulb should light up as brightly as before.
R 452
P5
P4
ST2
Frequency
P3
P2
Voltage
Ref. 3563 GB - 4.33 / a - 01.02
ASSEMBLY B
Exciter field
6 -
+
-
AC
220 V
According to mains frequency 200 - 240 V
ST3
X2
50Hz 60Hz Z1
X1
ST5
Z2
E+
E-
0V
ST1
P1
220V
S1 S2
380V
ST4
5 +
Diode
5A
(220 V)
Mains
(Supply
50/60 Hz)
V
300 V :
D C
19