Overview
The MX322 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
- PMG-Powered — Independent excitation for superior stability
- 2.7A Continuous / 6A Intermittent — 120VDC max output
- ±1% Regulation — Tight voltage control for 100kVA class
- Soft Start Ramping — 3-second smooth voltage buildup
- Under-Frequency Protection — 95% Hz set point
- Half-Wave Thyristor — Proven reliable excitation control
Technical Specifications
| Parameter | Value |
|---|---|
| Type | Half-wave phase-controlled thyristor, PMG-powered |
| Sensing Input | 190-264VAC, 1-phase, 2-wire |
| Power Input (PMG) | 140-220VAC, 3-phase, 3-wire |
| Output Voltage | Max 120VDC |
| Output Current | Continuous 2.7A, Intermittent 6A for 10s |
| Regulation Accuracy | <±1% (with 4% engine governing) |
| Frequency | 50/60 Hz |
| Soft Start | 3 seconds ramp |
| UF Protection | Set point 95% Hz |
| Application | Up to 100kVA alternators |
Compatibility
Stamford alternators. Compatible with: MX322.
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 Stamford PMG type 100-500kW (MX322) and 300kW+ (MX450).
Competitors MX341 (mid-range), MX321 (high-performance).
| Parameter | MX450 | MX322 | MX341 |
| Current | 6A PMG | 4A PMG | 4A PMG |
| Regulation | ±0.5% | ±0.5% | ±0.5% |
| Price | $200-350 | $45-70 | $50-80 |
Selection Advice The MX450 is the highest-current MX series model (6A) — suitable for 300kW+ generator sets with large excitation demands that don’t require parallel operation. The MX322 is the entry-level PMG type with simplified features but the lowest price — suitable for budget-sensitive PMG requirements.
