When selecting a diesel generator set, consider its comprehensive performance and economic indicators, the location and actual professionalism of the generator manufacturer or dealer, and their after-sales service capabilities. Then, consider whether the power of the selected generator set matches the power load. The Cummins diesel generator set standard configuration includes not only the Cummins diesel engine and the Stamford generator as the main units but also the auxiliary components provided with it. You can understand the basic situation of the standard configuration by referring to the technical specifications in the Cummins power product manual, the quotation sheet, and the information published on the Cummins official website. If the standard configuration is missing, it will to some extent affect the operation and performance of the diesel generator set. This article by Cummins specifically describes the types and main functions of the optional and optional accessories for the diesel generator set.
I. Standard Optional Accessories Included with柴发
The diesel generator set is primarily composed of three major components: Cummins diesel engine, Stanford generator, and PC3.3 control system. Taking the Cummins generator set model C220D5 as an example, its structure and layout are shown in Figures 1 and 2. The standard configuration includes the following:
1. Features of Cummins diesel engines
(1) Cylinder body
Enhanced ribbing arrangement and wide skirt design improve the cylinder's rigidity and strength, reducing vibration and noise, thereby enhancing the engine's reliability.
② Large cylinder bore design, accommodating 4 larger valves, not only reduces intake resistance and improves filling efficiency, enhances fuel economy, but also extends valve life and boosts engine reliability.
③ Added special oil and water extraction holes, as well as mounting holes for STC and electronic fuel injection systems, which is conducive to the future development and application of electronic fuel injection technology.
④ Increased optional installation positions for fan bracket to enhance rigidity.
⑤ Utilizes a standard low-pressure cylinder sleeve, with improved surface roughness.
(2) Cylinder Head
One pot, one cover, easy for maintenance.
② Utilizes a four-valve (two intake and two exhaust) configuration, which reduces intake resistance, significantly enhancing filling efficiency and promoting more complete combustion.
③ The exhaust outlet and exhaust duct have been improved to a transition change structure, utilizing pulsating airways for optimal utilization of waste gas energy.
④ High-strength cast iron material is selected, further enhancing the cylinder head's impact resistance. Increased valve stiffness results in stronger over-revving capability of the engine.
(3) Crankshaft
Forged from high-strength alloy steel material, enhancing crankshaft strength and lifespan.
② Increased overlap of the main shaft neck effectively enhances the crankshaft's rigidity and strength, boosting reliability.
③ The original crankshaft structure was a镶balance weight structure, but now it has been upgraded to an integrated crankshaft structure, significantly reducing the failure rate of the crankshaft and enhancing its reliability.
④ Induction hardening at corner, enhancing the crankshaft's strength; induction hardening to a depth of 2.2mm on the crankshaft journals, improving wear resistance.
(4) Pistons and connecting rods
The piston is made of suitable aluminum alloy material, featuring low inertia during high-speed operation, good thermal conductivity, and sufficient strength to meet working requirements.
② The barrel face design of the piston skirt ensures proper fit during operation, providing ample bearing surface without being too tight or causing knocking due to excessive clearance.
③ The connecting rod is forged from high-strength alloy steel, enhancing its strength.
④ Type I linkage structure, ensuring the required strength with less material.
Camshaft
Manufactured from high-strength alloy steel material, enhancing the camshaft's strength and lifespan.
② Employing a large-diameter camshaft and large cam structure, the intake profile is improved, which slows down the valve seating speed and reduces impact force, thereby enhancing valve wear. Additionally, vibration is minimized, leading to increased engine reliability and durability.
③ Cam surface super-finished polishing ensures reliable cam motion path.
(6) Turbocharger
Utilizing small wheel diameters, the compact structure offers high compression ratios and a wide flow range, effectively reducing the engine's exhaust temperature, improving emissions performance, and enhancing reliability. It meets the requirements of high-power engines and the matching needs of engines operating at high altitudes.
2. Features of Stanford Generator
Insulation and varnishing:
The insulation grade is "H" class. All wound components are made from specially formulated materials and treated with a special varnishing process, ensuring reliable operation of the generator in harsh environments. The specially developed resin-based material provides high processing strength and high mechanical strength for the coils and rotating parts.
(2) Winding and electrical performance:
All Stanford generator windings are wound with a 2/3 pitch, effectively eliminating the third and multiples of the third harmonic voltages, and are designed for non-linear loads such as uninterrupted power supply equipment. When paralleled with the grid, the 2/3 pitch structure suppresses excessive midline current that can be produced by larger coil pitches. A fully continuous damping winding reduces oscillations during parallel operation of the generator. This 2/3 pitch winding, with poles and teeth carefully selected, matches to suppress waveform distortion of the output voltage.
(3) Overload Capacity:
The Stanford land-based generator can operate at 110% overload for 1 hour every 12 hours.
(4) Phone Interference:
THF (as defined by BS EN60034—1) is less than 2%. TIF (as defined by NEMA Mgl-22) is less than 50.
(5) Radio Frequency Interference (RFI)
Brushless units and high-quality AVR ensure minimal interference during radio transmission, meeting BSEN61000-6 standard requirements. An additional Radio Frequency Interference Suppressor (RFI) can be provided upon request.
(6) Terminal Blocks and Connectors Boxes
Standard generators are three-phase and capable of reconnecting the 12 terminal heads connected to the terminal blocks, which are mounted on the output board of the generator's non-driven end. The outlet box made of steel plate contains an AVR and provides ample space for user wiring. For ease of operation, the panel is a removable panel.
3. Control System
Control systems refer to the controller section and its matching electrical components and electrical elements. Controllers are mainly categorized into single machine controllers, multi-machine parallel controllers, and unattended three-reach controllers. Electrical components generally include: circuit breakers, relays, speed control plates, sensors, meters, etc.
4. Randomly Required Accessories
(1) Suitable for 40℃/50℃ environment radiator reservoir, belt-driven cooling fan, fan safety guard.
Section 2: Optional Accessories for Diesel Generators
The so-called optional accessories are clearly components that are not part of the standard configuration of a diesel generator set. These are designed to enhance the functionality and performance of the power generation product, and they are additional items that require separate purchase. The following devices are optional, and it is necessary to declare the additional purchase requirements in advance when ordering from the diesel generator manufacturer to ensure the desired functionality after installation.
Battery Floating Charger
External floating charger with strong charging function, capable of rapidly charging lead-acid batteries and also performing regular charging on battery cells. Its appearance is shown in Figure 3, and the wiring diagram is shown in Figure 4. Once the strong charging mode is selected, the output voltage will rise by 0.35V. (Note: The strong charging mode must be charged according to the instructions provided by the battery manufacturer. Failure to do so may damage the battery and increase maintenance costs.) Standard:
Operation:
The charger outputs current K to the battery terminal voltage until it reaches the float charge K setpoint, which is pre-set. When the battery voltage drops to the lower limit due to load usage, the charger will re-supply output current to charge the battery M up to its terminal voltage H. The shutdown setpoints are listed in Table 1 below.
(2) AC Input: 220-250VAC, 50/60Hz (specify at time of order)
(3) Output Current: 3A or 5A (specify at time of order)
(4) Environmental Temperature Range: -10 to +60°C
(5) Indicator Light: LED Charger Indicator Light
(6) Protection Functions: Short circuit, overvoltage 11, overcurrent, polarity reversal, reverse charging mode: higher float voltage by 0.35V.
(7) DC Output: Rated 12VDC or 24VDC (specify at time of order)
2. Storage Tank
The fuel tank of the generator set should be capable of providing fuel for continuous operation at full load for over 8 hours, and it is advisable to avoid refueling the tank while the generator set is running. After the fuel tank is placed, the oil level should not exceed 2.5 meters above the base of the diesel generator. If the oil level in the outdoor fuel tank is higher than 2.5 meters, an additional fuel tank should be installed between the outdoor fuel tank and the diesel generator set to ensure that the direct oil supply pressure does not exceed 2.5 meters. Even during the shutdown of the diesel generator, fuel is not allowed to flow into the diesel engine by gravity through the intake or fuel injection lines.
3. Dual Power Conversion Cabinet
The main power switch is available in manual and automatic types (abbreviated as ATS). If your diesel generator is used as a backup power source, it is mandatory to install a main power switch at the power input point. It is strictly prohibited to input the self-generated power into the load by relying on temporary wiring methods or memory-based operations. Because once the self-generated power is improperly connected to the grid (referred to as reverse power supply), it can cause serious consequences such as injuries and equipment damage. The correct installation of the switch must be inspected and approved by the local power supply department before it can be put into use.
4. Parallel cabinet
The paralleling cabinet for diesel generators is equipped with an automatic management system to accommodate the simultaneous use of two or more generators, featuring all the functions of a manual paralleling panel. When the switch is set to the "Automatic" position, the automatic synchronizer can automatically adjust the frequency and phase of the generators to be paralleled, outputting a closing signal during synchronization to achieve automatic paralleling. An integrated programmable controller is capable of automatically controlling load balancing, load requirements, and scheduling of generator operation, ensuring reliable grid operation. In the event of a power failure, it can automatically start the generator set, perform automatic paralleling, and monitor various faults in the paralleled system.
5. Water Heater
The diesel generator set water jacket heater maintains a certain temperature for the engine, preventing the generator set from cracking in winter and enabling quick and rapid starting of the diesel engine in extreme cold temperatures. The water jacket heater keeps the temperature of the water in the generator set within the set temperature range (about 35 °C), indirectly heating the lubricating oil due to heat transfer, thereby avoiding condensation. This keeps the diesel generator set in a hot standby state, allowing it to start on emergency at any time during the harsh winter and quickly load up to full capacity. The mechanical wear of the diesel generator set is reduced, and the output power is stable. The structure of the water jacket heater is shown in Figure 5.
6. Oil Heater
The oil heater is typically used as a heating element in the fuel tank of a generator set to preheat the engine. By adding such a device, the generator set can still start normally even in cold conditions or in environments with low temperatures. In cold environments, such as winter in northern regions of our country, the engine in the generator set may not reach the ignition point of the oil in the tank due to the influence of external temperatures, leading to difficulties in starting the generator set in cold conditions. Using a heater for preheating can help ignite the generator set and serves as a safeguard. The appearance of the oil heater is shown in Figure 6.
7. Silent-type Generator Set
Silent-type generator sets primarily refer to those equipped with protective enclosures, mainly categorized into silent box-type generator sets (as shown in Figure 7) and container-type generator sets (as shown in Figure 8). Key features include low noise levels and high mobility. With the continuous development of urbanization, the demand for power facilities in construction, backup, and guarantee power sources is increasingly high, especially for key performance characteristics such as noise control, design aesthetics, and equipment hoisting.
Summary:
Selecting brand suppliers with excellent after-sales service and maintenance support ensures reliable electricity usage. As diesel generators are a long-term investment, they may require regular maintenance and repairs. Reliable service support guarantees the long-term reliability of the equipment. Since diesel generator sets play a crucial role in various fields, understanding their configurations, application areas, and selection considerations can help in choosing the right diesel generator set and ensure a reliable power supply.
