LEROY SOMER R449 AVR

Features and specification
R449 AVR is used on LEROY SOMER LSA 50.1 and LSA 51.2 alternators with AREP or PMG excitation.
With AREP excitation, the R 449 electronic AVR is powered by two auxiliary windings which are independent of the voltage detection circuit. The first winding (X1, X2) has a voltage proportional to that of the alternator (Shunt
characteristic), the second (Z1, Z2) has a voltage proportional to 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 449 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. The exciter field is fitted with permanent magnets in series (PMI system) which provide constant remanent voltage.
– Load current: 7A
– overload current: 15A – 10s
– electronic protection (overload, voltage detection opening, short-circuit): excitation overload current for 10 s then return to approximately 2A.
The alternator must be stopped (or the power switched off ) in order to reset the protection.
– fuses outside AVR 16A – 500 V
– voltage detection: 5 VA isolated via transformer
– 110 V terminals = 85 to 130 V
– 220 V terminals = 170 to 260 V
– 380 V terminals = 340 to 520 V
UN∨ 480V voltage detection via step-down transformer
(Option)
– voltage regulation &plus mn; 0.5%
– voltage adjustment via potentiometer P2
– current detection: (parallel operation): C. T. 10 VA CL1, secondary 1.2 A (Option)
– quadrature droop adjustment via potentiometer P1
– under-speed protection (U/f) and LAM: frequency threshold adjustable via potentiometer P4
– max. excitation current adjustment via P5: 4.5 to 15A
– 50/60 Hz selection via strap ST3
– 2 voltage recovery modes (normal/fast) selected via ST2 and adjusted via P3 (stability).