Leroy Somer LSA 49.1 4P Manuel D'utilisation Et D'entretien page 36

LEROY-SOMER
3.5.1 - R 448 settings
WARNING
Before any intervention on the AVR, make sure that the
ST9 jumper is closed with AREP excitation and
disconnected with PMG excitation.
a) Initial potentiometer settings (see table below)
- Remote voltage adjustment potentiometer :
centre (ST4 jumper removed).
Action
Voltage
minimum fully anti-clockwise
Stability
Threshold/LAM or U/F
Underspeed protection
and "LAM" trip threshold
Maximum frequency fully
anti-clockwise
Voltage quadrature droop
(// operation with C.T.)
- 0 quadrature droop fully
anti-clockwise.
Excitation ceiling
Limit of excitation ceiling
and short-circuit current,
minimum fully anti-clockwise
Adjustments in standalone operation
b) Install a D.C. analogue voltmeter (needle dial) cal. 100V on
terminals E+, E- and an A.C. voltmeter cal 300 - 500 or 1000V
on the alternator output terminals.
c) Make sure that the ST3 jumper is positioned on the desired
frequency (50 or 60 Hz).
d) Voltage potentiometer P2 at minimum, fully anti-clockwise.
e) Turn the V/Hz potentiometer P4 fully clockwise.
f) Stability potentiometer P3 to around 1/3 of the anti-
clockwise limit.
12
INSTALLATION AND MAINTENANCE
LSA 49.1 4P
ALTERNATORS
INSTALLATION
Factory setting Pot.
400V - 50 Hz
(Input
P2
0 - 380 V)
Not set
P3
(centre position)
If ST3 = 50 Hz
(factory) = 48 Hz
P4
If ST3 = 60 Hz
(factory) = 58 Hz
Not set
(fully anti-
P1
clockwise)
10 A
P5
maximum
g) Start the engine and set its speed to a frequency of 48 Hz
for 50 Hz, or 58 for 60 Hz.
h) Set the output voltage to the desired value using P2.
- Rated voltage UN for solo operation (eg. 400 V)
- Or UN + 2 to 4% for parallel operation with C.T. (eg. 410 V)
If the voltage oscillates, use P3 to make adjustments (try both
directions) observing the voltage between E+ and E- (approx.
10V D.C.). The best response times are obtained at the limit
of the instability. If no stable position can be obtained, try
disconnecting or replacing the ST2 jumper (normal/fast).
i) Check LAM operation : ST5 closed.
j) Turn potentiometer P4 slowly anti-clockwise until there is a
significant voltage drop (approximately 15%).
k) Vary the frequency (speed) around 48 or 58 Hz according
to the operating frequency, and check the change in voltage
from that observed previously (~ 15%).
l) Readjust the speed of the unit to its rated no-load value.
Adjustments in parallel operation
Before any intervention on the alternator, make sure that
the speed droop is identical for all engines.
m) Preset for parallel operation (with C.T. connected to S1,
S2)
- Potentiometer P1 (quadrature droop) in centre position.
Apply the rated load (cos Ø = 0.8 inductive).
The voltage should drop by 2 to 3%. If it increases, swap the
2 incoming wires of the C.T. secondary.
n) The no-load voltages should be identical for all the
alternators intended to run in parallel.
- Couple the machines in parallel.
- By adjusting the speed, try to obtain 0 KW power exchange.
- By altering the voltage setting P2 or Rhe on one of the
machines, try to cancel (or minimise) the current circulating
between the machines.
From now on, do not touch the voltage settings.
o) Apply the available load (the setting is only correct if a
reactive load is available)
- By altering the speed, match the KW (or divide the rated
power of the units proportionally)
- By altering the quadrature droop potentiometer P1, match or
divide the currents.
Ref. 3007 GB - 4.33/a - 10.00