Overview
The R450 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
- ±0.5% Regulation — High-precision transistor-controlled AVR
- 6A Nominal Output — 63VDC max, 10A max for 10 seconds
- Wide Alternator Support — LSA40 through LSA50.2, TAL40-TAL49
- 85-139VAC Sensing — 50/60Hz selectable
- Transistor-Controlled — Faster response than thyristor AVRs
- 12-Lead Option Compatible — Flexible alternator configurations
Technical Specifications
| Parameter | Value |
|---|---|
| Sensing Input | 85-139VAC (50/60Hz) |
| Output Voltage | Max 63VDC |
| Output Current | Nominal 6A, Maximum 10A for 10s |
| Regulation Accuracy | <±0.5% |
| Frequency | 10-100 Hz |
| Excitation Type | Self-excited shunt (transistor-controlled) |
| UF Function | 1.07 U/F (k=1) |
| Fuse Protection | 8A |
Compatibility
Leroy Somer alternators. Compatible with: R450.
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 100-3000kW, next-generation replacement for R438.
Competitors R438 (Leroy Somer previous generation), MX321 (Stamford).
| Parameter | R450 | R438 | MX321 |
| Output Current | 6A cont. | 4A cont. | 5A cont. |
| Adjustment Method | Digital calibration | Potentiometer manual | Potentiometer manual |
| Parallel Operation | Yes | No | Native support |
| Voltage Sensing | Built-in (no R731) | Needs R731 | Built-in |
| Price | $220-380 | $200-350 + R731 | $180-300 |
Selection Advice The R450 is the next-generation replacement for the R438. Three key upgrades over R438: (1) 6A output — 50% more excitation capacity; (2) digital calibration replaces potentiometers — no screwdriver adjustment needed, precise digital display, installation time halved; (3) eliminates the external R731 module — integrated design for simpler installation. If replacing an old R438, upgrading directly to R450 is recommended over buying another R438. For parallel operation needs, choose MX321 or R450.
