The ARCO Zeus 24V 4kW Low Turn-On (LTO) alternator delivers exceptional high-output charging performance optimized for marine diesel engines, RVs, and commercial applications. This advanced alternator features a native 24V rotor and field current design that runs significantly cooler and more efficiently than competitors' 12V rotor-based 24V alternators, directly extending service life.
Engineered for superior low-RPM performance, this alternator generates over 1.4kW (51 Amps) at just 1,500 alternator RPM and nearly 2.4kW (87 Amps) at 2,000 RPM. In real-world conditions, a marine diesel at 750 RPM with a 2:1 pulley ratio produces over 1.5kW (55 Amps), while a Mercedes Sprinter at 750 RPM with 3.21:1 pulley ratio generates over 2.5kW (91 Amps). This exceptional low-speed output makes it ideal for rapidly charging large battery banks without running a generator.
Key Features:
- Native 24V rotor and field current for cooler operation and longer life
- Low turn-on design with cut-in at 1,072 alternator RPM
- Dual cooling fans with heat-shedding E-coat/Cerakote finish
- External-mounted rectifier for improved heat dissipation
- Maximum output: 144 Amps (3,960 Watts) at 9,000 RPM cold
- Sustained cruising output: 130 Amps (3,575 Watts) at 6,000 RPM hot
- Isolated ground configuration for Common Rail applications
- SAE J1171 Certified
- Compatible with ARCO Zeus Bluetooth regulator for lithium battery charging
- OEM-grade components throughout
- Proudly made in the USA
Technical Specifications:
- Voltage: 24V with external regulation only
- Output Rating: 4kW nominal, 5.7kW PTO maximum
- Field Type: P-type, 16 rotor poles
- Stator: 138mm large frame
- Diodes: 6 positive, 6 negative, 50A rated avalanche type
- Maximum alternator RPM: 19,000
- Maximum continuous operating temperature: 100°C (212°F)
- Battery post: M8 thread, side mount
- Standard pulley: 49K6 (6-groove, 49mm diameter)
- Pulley mount: 17mm diameter shaft, 25mm long, threaded M17 x 1.5
- Includes: M17 x 1.5 x 24mm nut with washer
- Finish: Black E-coating
- Weight: 15.89 lbs (7.2 kg)
Application Note: This alternator with isolated ground must be used on Yanmar Common Rail engines introduced after 2013, including models JH-CR, 3JH40, 4JH45, 4JH57, 4JH80, and 4JH110.
