Alpha Compact 28/110 Alternator with Alpha Pro III
In stock
Technical specifications
Technical specifications
| Series | Alpha Compact |
| Nominal voltage | 24.0 |
| Nominal current | 110.0 |
| Power | 6.2 |
| Max rotation speed | 15000.0 |
| Cut-in speed | 1400 |
| Idle current | 41.0 |
| Mounting style | Gimbal arm |
| Rotation direction | Clockwise direction |
| Galvanic isolation | Uninsulated |
| Field control type | Negative (N-type) |
| Housing temperature sensor support | Oui |
| Min pulley diameter | 53.3 |
| Max pulley diameter | 71.1 |
| Min pulley ratio | 2.25 |
| Max pulley ratio | 3.0 |
| Cooling method | Dual integrated fans |
| Cooling fan count | 2.0 |
| Max operating temperature | 120.0 |
| Température d'arrêt de charge | 120.0 |
| Weight | 7.4 |
| Marine-ready | Oui |
| Taille du terminal de sortie (mm) | M8 |
Detailed description
Detailed description
The Mastervolt Alpha Compact 28/110 alternator (part number 46628110) is a 24 V DC charging system designed for marine, mobile, and industrial applications requiring continuous power supply. It is supplied as standard with the external Alpha Pro III charge regulator, forming a complete solution compatible with the MasterBus network. This equipment enables rapid charging of service battery banks while powering onboard electrical consumers.
Positioning and comparison
Unlike original alternators installed by engine manufacturers, which are often limited at low RPM, the Alpha Compact 28/110 is specifically wound to deliver high charging current even at idle. Compared to the standard Mastervolt Alpha range, this Compact series features an automotive-style design that reduces volume by 25% and weight by 40%, while cutting fuel consumption by up to 30% thanks to improved efficiency. Within its own range, this standard model differs from the "VP" (Volvo Penta) version by the absence of an included pulley. This design choice allows the installation of a multi-groove free-wheel pulley with a diameter matching the target installation’s speed ratio.
Electrical and thermal specifications
This alternator delivers a nominal current of 110 A at 6,000 RPM and 25 °C. Its charging capacity at idle reaches approximately 41 A at 1,800 RPM. The startup speed is set at 1,400 RPM, with a maximum tolerated speed of 15,000 RPM. It requires a power take-off (PTO) of 6.2 kW (8.3 hp). The unit is designed to operate in confined engine rooms, with a maximum operating temperature of 120 °C. Cooling is provided by an open design featuring a dual internal fan and a patented magnetic circuit that optimizes thermal dissipation.
Alpha Pro III Regulation and MasterBus Compatibility
The alternator is controlled by the included Alpha Pro III regulator (firmware 4.0 or higher). This device uses a three-stage charging cycle (Bulk, Absorption, Float) that compensates for voltage drops and adjusts current based on real-time needs. The system supports all battery chemistries: flooded lead-acid, GEL, AGM, and Lithium-Ion. Native integration with the MasterBus protocol allows configuration of charging parameters, real-time monitoring, event history, and system alarm settings for the power production setup.
Mechanical Design and Connectivity
Weighing 7.4 kg, the alternator has a clockwise rotation direction and is mounted via a swivel arm, simplifying installation as a secondary alternator on original PTO mounts. The electronic components and wiring are protected against oil, moisture, and dust. The chassis is uninsulated by default; galvanic isolation requires optional rings. Connection interfaces include two M8 studs for the positive output, an insulated Fast-on terminal for the W signal (tachometer), a Mastervolt-specific port for excitation current, and an RJ12 port for connecting the alternator’s integrated temperature sensor.
Expert opinion
Expert opinion
Pol CONIN
Digital Manager
« 24V optimized power generation for confined engine rooms »
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