Overview
The R448 is an Automatic Voltage Regulator (AVR) that maintains the generator output voltage within precise limits by controlling the exciter field current. It continuously samples the generator output voltage and adjusts excitation to compensate for load changes, engine speed variations, and temperature drift.
Key Features
- ±1% Regulation — Reliable voltage control for industrial generators
- 10A Continuous Output — High-current capacity for large alternators
- 120/240VAC Selectable — Jumper-configurable sensing input
- PMG or Shunt Excitation — Dual excitation compatibility
- Soft Start Ramping — Smooth voltage buildup on startup
- Under-Frequency Protection — Automatic voltage reduction below threshold
- Sensing Loss Protection — Prevents over-voltage on signal loss
Technical Specifications
| Parameter | Value |
|---|---|
| Model | R448 |
| Sensing Input | 120/240VAC jumper selectable |
| Output Voltage | Max 150VDC |
| Output Current | Continuous 10A |
| Regulation Accuracy | <±1% |
| Frequency | 50/60 Hz |
| Excitation Type | Shunt or PMG |
Compatibility
Leroy Somer alternators. Compatible with: R448.
Why Choose ZenixPower
- Tight Voltage Regulation — <±1% RMS regulation ensures stable generator output under 0-100% load transients
- Fast Response — Sub-0.5 second recovery time prevents voltage dips during motor starting and load switching
- Dual Excitation Compatibility — Self-excited shunt or PMG-powered configurations clearly labeled for correct selection
- Built-in Protections — Under-frequency roll-off, over-excitation limiting, and soft-start ramp as standard
- Drop-In Replacement — Terminal layout and mounting dimensions match STAMFORD, Leroy-Somer, Marathon, and Mecc Alte OEM AVRs
- Pre-Calibrated — Each AVR ships with factory-default potentiometer settings for immediate plug-and-play operation
Specification Comparison
Compatible Generators Leroy Somer LSA 46-49 series 3000kW+ very large generators.
Competitors R449 (PMG type), R450 (next generation).
| Parameter | R448 | R449 | R450 |
| Output Current | 10A | 7A | 6A |
| Regulation | ±1% | ±0.5% | ±0.5% |
| Applicable Power | 3000kW+ | 100-3000kW | 100-3000kW |
Selection Advice The R448 has the highest current in the Leroy Somer series (10A), specifically designed for 3000kW+ very large generators. Its excitation capacity is 1.7x the R450 and 2.5x the R438. For generators below 2000kW, the R450 is fully sufficient with higher accuracy (±0.5% vs ±1%). The R448 is irreplaceable only in the very large power range.
