Description
The R438 automatic voltage regulator (AVR) circuit provides closed-loop control of the generator output voltage by means of regulatin exciter field current, R438 can be powered by the EREP or PMG field excitation system and can be installed as an option in:
-100 series generators
-200 series generators
-300 series generators
With the AREP excitation system, the R438 AVR is powered by two auxiliary windings that are independent of the voltage sensing circuit, and with the PMG option, the R438 AVR is powered by the PMG that is installed at the rear end of the generator.
Voltage regulation < ± 0.5%.
Load Acceptance Module (LAM)
50/60 Hz selectable.
Low Frequency & Exc. Maximum protection.
Optional single-phase or three-phase voltage sensor
Soft start voltage ramp.
Normal fast response time (option)
Voltage sensor: terminal 0-110 V = 95-140 V.
terminal 0-220 V = 170-260 V.
terminal 0-380V=340-520V
Frequency: 50-60 Hz.
Input voltage: 40 – 50 V AC, 3 phases.
Auxiliary armpnic winding: 6 – 150 V AC (no load rms).
Output:
Voltage: max. 160 V DC to 120 V AC.
Current: max. 8 A.
Resistance: 15 Ω minimum.
Regulation:+/-5% RMS with 4% motor control
Voltage setting: residual voltage at terminals avr ≥ 5AC
Adjustable external voltage: +/-10% with 1 K ohm trimmer of 1 W.
