Overview
The BE350 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
- 4A Continuous Output — 63VDC max, 6A forcing for 1 minute
- Better than ±1% Regulation — No-load to full-load accuracy
- Self-Excited Shunt — Simple, reliable excitation
- Frequency Compensation — U/F limiting built-in
- Overexcitation Shutdown — Adjustable protection threshold
- Build-Up from 6VAC — Low residual voltage capable
- Rugged Potted Design — Harsh environment operation
Technical Specifications
| Parameter | Value |
|---|---|
| Input Power | 95-139VAC, ±10%, 50/60Hz |
| Sensing Input | 95-139VAC ±10% or 190-277VAC ±10% |
| Output Voltage | Max 63VDC at 4A DC (252W) |
| Forcing Output | 90VDC at 6A DC (540W) for 1 minute |
| Regulation Accuracy | Better than ±1%, no-load to full-load |
| Excitation Type | Self-excited shunt |
| UF Compensation | Yes |
| Overexcitation Shutdown | Yes, adjustable |
| Min Field Resistance | 15 ohms |
| Response Time | <1.5 cycles |
| Operating Temp | -40°C to +60°C |
| Voltage Buildup | As low as 6VAC residual |
Compatibility
Marathon MAGNAPLUS 50-200kW generators.
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 Marathon MAGNAPLUS 50-200kW.
Competitors SE350 (Marathon fully sealed), SX460 (Stamford universal).
| Parameter | BE350 | SE350 | SX460 |
| Output | 4A | 3.5A | 4A |
| Enclosure | Standard | Fully sealed potted | Standard |
| Brand | Marathon (USA) | Marathon (USA) | Stamford (UK) |
| Price | $40-60 | $50-80 | $25-45 |
Selection Advice
The BE350 is Marathon’s entry-level economy AVR, suitable for clean, dry indoor generator rooms. If brand is not a concern, the SX460 may be less expensive ($25-45 vs $40-60) with identical parameters. If Marathon brand is specified but budget is limited, the BE350 is appropriate. For outdoor or wet environments, the SE350 is required.
