4946255
Alternator
Cummins®

Introduction

The Cummins 4946255 Alternator is a component designed for use in commercial trucks. It generates electrical power and maintains the charge of the vehicle’s battery, ensuring the reliable operation of electrical systems within the truck and contributing to overall vehicle performance and efficiency.

Basic Concepts of Alternators

An alternator converts mechanical energy into electrical energy. It functions by using a rotor that spins within a stationary set of coils, known as the stator, to generate alternating current (AC). This AC is then converted into direct current (DC) by a rectifier, which is used to charge the battery and power the vehicle’s electrical systems ¹.

Purpose of the Cummins 4946255 Alternator

The Cummins 4946255 Alternator is specifically engineered to meet the demanding requirements of commercial trucks. It generates electrical power to support the truck’s electrical systems and maintains the battery’s charge during operation. This ensures that the truck can operate its lights, electronics, and other electrical components reliably, even under heavy load or extended use ².

Key Features

This Cummins part is characterized by its robust design and construction, utilizing high-quality materials to ensure durability and performance. Its design includes features that enhance efficiency and reliability, such as advanced cooling systems and precision-engineered components. These attributes contribute to its ability to perform under the rigorous conditions typical of commercial truck operations ³.

Benefits

Utilizing the 4946255 offers several advantages. Its design and construction contribute to improved efficiency, allowing for optimal electrical power generation with minimal energy loss. The alternator’s durability ensures long-term reliability, reducing the need for frequent replacements. Additionally, its performance is enhanced by features that ensure consistent operation across a wide range of operating conditions.

Troubleshooting and Maintenance

Common issues with the 4946255 may include electrical faults, bearing wear, or rectifier failures. Troubleshooting steps may involve checking electrical connections, testing output voltage, and inspecting for signs of wear or damage. Regular maintenance practices, such as cleaning the alternator and checking belt tension, can help ensure optimal performance and longevity.

Integration with Truck Systems

The 4946255 integrates seamlessly with other systems within a commercial truck. It works in conjunction with the engine to generate power, the battery to store and supply electrical energy, and the electrical components to distribute power throughout the vehicle. This integration ensures that the truck’s electrical systems operate efficiently and reliably.

Performance in Various Conditions

The 4946255 is designed to perform under a variety of operating conditions. It can handle extreme temperatures, heavy loads, and varying speeds, ensuring consistent electrical power generation and battery charging. Its robust construction and advanced features allow it to maintain performance even in the most demanding environments.

Historical Development

The development of alternators has evolved significantly over the years, with advancements in technology and design leading to more efficient and reliable components. The 4946255 is a product of this progression, incorporating the latest innovations to meet the needs of modern commercial trucks.

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a reputation for innovation and quality, Cummins has a long-standing commitment to providing reliable and efficient components for the automotive and heavy-duty truck industries. The company’s focus on research and development ensures that its products, including the 4946255, meet the highest standards of performance and durability.

Compatibility

This alternator is designed to fit a variety of Cummins engines, ensuring reliable power generation across different engine models. It is engineered to meet the specific electrical needs of the engines it supports, providing consistent performance and durability.

Compatible Engines

• 6C8.3
• ISL9 CM2150 SN
• ISL9.5 CM2880 L138
• L8.9G CMOH2.0 L125B
• L9 CM2670 L128B
• QSC8.3 CM2880 C102
• QSL8.9 CM2150 L141
• QSL9 CM850 (CM2850)
• QSL9.3 CM2880 L113

Grouping of Compatible Engines

The 4946255 is compatible with a range of Cummins engines, grouped by their model series and specifications:

• 6C8.3
• ISL Series
  • ISL9 CM2150 SN
  • ISL9.5 CM2880 L138
  • QSL9 CM850 (CM2850)
  • QSL9.3 CM2880 L113
• L Series
  • L8.9G CMOH2.0 L125B
  • L9 CM2670 L128B
• QSC Series
  • QSC8.3 CM2880 C102
• QSL Series
  • QSL8.9 CM2150 L141

This compatibility ensures that the alternator can be used across multiple engine models, providing a versatile solution for maintaining the electrical systems of these engines.

Role of Part 4946255 Alternator in Engine Systems

The alternator, specifically part 4946255, is integral to the operation of various engine systems. It serves as the primary source of electrical power once the engine is running, ensuring that all electrical components receive a consistent and reliable power supply.

Electrical System Integration

In the electrical system, the alternator charges the battery while the engine is operational, maintaining the battery’s charge level and providing power to the vehicle’s electrical components such as lights, ignition system, and onboard computers. It works in conjunction with the voltage regulator to maintain a stable output voltage, typically around 13.5 to 14.5 volts, which is essential for the proper function of electronic systems and to prevent overcharging of the battery.

Ignition System Support

For the ignition system, the alternator ensures that the spark plugs receive a consistent spark by providing a steady power supply to the ignition coil. This is particularly important in modern engines where precise timing and consistent spark are required for optimal performance and fuel efficiency.

Fuel Injection System

In fuel-injected engines, the alternator plays a role in powering the fuel injection system. It provides the necessary electrical energy to the fuel injectors, ensuring they operate with precision and deliver the correct amount of fuel into the combustion chamber. This contributes to efficient fuel consumption and reduced emissions.

Engine Control Unit (ECU) Functionality

The alternator is also vital for the operation of the Engine Control Unit (ECU). The ECU relies on a stable power supply to monitor and control various engine parameters such as fuel delivery, ignition timing, and emissions systems. A well-functioning alternator ensures the ECU can perform its tasks accurately and efficiently.

Accessory Power

Beyond the core engine systems, the alternator powers various vehicle accessories such as the air conditioning compressor, power steering pump, and entertainment systems. It ensures these components operate smoothly and do not drain the battery excessively when the engine is running.

Starting System Interaction

Although the alternator does not directly interact with the starting system during cranking, its role in maintaining battery charge is essential. A well-charged battery, thanks to the alternator, ensures reliable starting performance and reduces the likelihood of starting issues due to a weak battery.

Conclusion

In summary, the 4946255 is a cornerstone component that supports the electrical integrity and operational efficiency of multiple engine and vehicle systems. Its reliable performance is fundamental to the overall functionality and longevity of the engine and associated systems.