Excitation System; Power Supply Connection - Leroy Somer LSA 49.1 4P Manuel D'utilisation Et D'entretien

LEROY-SOMER

2.3 - Excitation system

For both AREP & PMG excitation systems, the alternator
voltage regulator is the R 448.
With AREP excitation, the R 448 electronic AVR is powered
by two auxiliary windings which are independent of the
voltage match circuit. The first winding has a voltage in
proportion with that of the alternator (Shunt characteristic),
the second has a voltage in proportion with the stator current
(compound characteristic : Booster effect). The power supply
voltage is rectified and filtered before being used by the AVR
monitoring transistor. As a result the machine has a
short-circuit current capacity of 3 IN for 10 s, and good
immunity to distortions generated by the load.
With PMG excitation, a permanent magnet generator (PMG)
is added to the alternator. This is fitted at the rear of the
machine and connected to the R 448 AVR.
The PMG supplies the AVR with voltage which is independent
of the main alternator winding. As a result the machine has a
short-circuit current capacity of 3 IN for 10 s, and good
immunity to distortions generated by the load.
The AVR monitors and corrects the alternator output voltage
by adjusting the excitation current.
WARNING
The ST9 jumper must be disconnected for operation
using the PMG system (R448 LS D version).
2.3.1 - R 448 AVR
- shunt power supply : max 150V - 50/60 Hz
- rated overload current : 10A - 10s
- electronic protection (overload, voltage sensing opening
short-circuit) : excitation overload current for 10 s then return
to approximately 1A.
The alternator must be stopped (or the power switched
off, see section 3.5.3) in order to reset the protection.
- Fuses :
• F1 on X1,X2.
• F2 on the exciter winding E+, E-.
- voltage sensing : 5 VA isolated via transformer
• 0-110 V terminals = 95 to 140 V
• 0-220 V terminals = 170 to 260 V
• 0-380 V terminals = 340 to 520 V
- voltage regulation ±0.5%
- normal or rapid response time via jumper ST2
- voltage adjustment via potentiometer P2
other adaptation transformer voltages
6
INSTALLATION AND MAINTENANCE
LSA 49.1 4P
ALTERNATORS
TECHNICAL CHARACTERISTICS
- current detection : (parallel operation) :
C.T. 2.5 VA cl1, secondary 1A (optional)
- quadrature droop adjustment via potentiometer P1
- underspeed protection (U/f) and LAM : frequency threshold
adjustable via potentiometer P4
- max. excitation current adjustment via P5 : 4.5 to 10A
- 50/60 Hz selection via jumper ST3.

2.3.2 - Power supply connection

AREP excitation
ST5
With LAM W/o LAM
ST2 normal fast
Response time
50Hz 60Hz
ST3
Frequency
P5
Excitation
ceiling
P4
R448
Under-
speed
P3
Stability
P2
Voltage
ST6
LSA 46.2/47.1
LSA 49.1
ST1
Single-phase
sensing
Option
3-ph sensing
ST4
Option
External potentiometer
Option
R731
for adjusting the voltage
Yellow
R 448 X2
Red
Z1
Green
X1
Black
Z2
E+
E -
Ref. 3007 GB - 4.33/a - 10.00
5+ 6 -
Field
Pwr supply
(see 2.3.2)
200 x 140 mm
4 x Ø5.8 x 175 x 115
F1
Fuses
250V 10 A
X2
Z1
X1
Z2
E+
E-
L3
0V
( W )
110
220
380
ST9
P1
AREP
Quad droop
PMG
C.T.
L2 ( V )
S2
S1
340-520V
170-260V
95-140V
Aux. windings
5 +
6 -
Exciter field