Diesel Generator
Question- What is Diesel Generator ?
Answer- A diesel generator (DG) is the combination of a diesel engine with an electric generator (often an alternator) to generate electrical energy.
Question: Why is regular load testing important for a DG set?
Answer: To ensure the generator can handle its rated load and identify performance issues before actual use.
Question: Why is battery health critical for DG operation?
Answer: Because the battery powers the starter motor; a weak battery can prevent the generator from starting.
Question: What is the function of the fuel-water separator in a DG set?
Answer: Fuel water separator purpose is to remove water and contaminants from diesel fuel, preventing injector and engine damage. It ensures smooth engine operation and prevents corrosion-related issues.
Question: What is meant by “DG synchronization”?
Answer: The process of matching voltage, frequency, and phase before connecting multiple generators to a common bus.
Question: What is the role of the governor in a diesel generator?
Answer: Governor is used to regulate engine speed and maintain stable frequency under varying loads.
Question: What is the role of the exhaust silencer in a DG set?
Answer: To reduce noise levels produced during engine operation. This ensures quieter functioning and minimizes noise pollution in the surrounding area.
Question: What is the function of a DG set canopy?
Answer: To reduce noise, protect the generator from weather, and enhance safety. Additionally, it enhances safety by preventing unauthorized access to moving parts.
Question: What is the role of emission control systems in modern DG sets?
Answer: Emission control systems in modern DG sets help reduce harmful gases like NOx, CO, and particulate matter. They ensure cleaner exhaust and minimize environmental impact. These systems also help DG sets comply with government emission norms and regulations.
Question: What should be checked during DG operation?
Answer: Monitor voltage, frequency, current, fuel level, oil pressure, coolant temperature, and any warning indicators.
Question: How do you safely shut down a DG set?
Answer: First remove the load, allow the engine to cool down by running idle for a few minutes, then stop the generator.
Question: What is the role of the emergency stop button?
Answer: To immediately shut down the DG set in case of fire, fuel leak, or other critical emergencies.
Question- Types of smoke ?
Answer- Basically there are 3 types of smoke emitted from a diesel engine: Grey, Dark black, blue and white.
Question- Types of service checks in DG-set & explain ?
Answer- DG sets undergo different types of maintenance checks:
A Check: Daily inspection for basic parameters and fluid levels.
B Check: Every 300 hours/ 6 months, includes filter change & system checks.
C Check: Every 1500 hours or 1 year, involves deeper inspection.
D Check: At 5000 hours, includes major overhauling and part replacements.
Question- Protection of DG set ?
Answer- DG have protections includes- Low lube Oil pressure, Low coolant, Over speed, High water temp etc. These parameters are continuously monitored to prevent engine damage. Automatic shutdown or alarms are triggered when any fault condition is detected.
Question- Types of filter ?
Answer- DG sets use various types of filters such as lube oil filter, air filter, fuel filter, coolant filter, and water separator. Each filter plays a specific role in removing impurities from its respective system. This ensures clean operation, protects engine components, and improves overall efficiency.
Question- How to check the battery gravity ?
Answer- Battery gravity in a DG set is checked using a hydrometer. It measures the specific gravity of the electrolyte to assess battery health and charge level. Regular checking helps ensure reliable starting and proper battery maintenance.
Question- What is output voltage of DG ?
Answer- The output voltage of a standard DG set is typically 415 volts in a three-phase system. This voltage is suitable for industrial and commercial electrical loads. It ensures stable power supply for connected equipment and systems.
Question- What is rated speed of DG ?
Answer- The rated speed of a standard DG set is 1500 RPM. This speed ensures optimal engine performance and stable power generation. It is commonly used for 50 Hz frequency systems in industrial and commercial setups.
Question- What is output frequency of DG-set ?
Answer- The output frequency of a standard DG set is 50 Hz, which matches the grid frequency used in India and many other countries. This frequency ensures compatibility with electrical equipment and stable power supply. Maintaining correct frequency is essential for efficient and safe operation of connected systems.
Question- What is range of lube oil pressure ?
Answer- The normal range of lube oil pressure in a DG set is between 2.5 to 7.5 kg/cm². This pressure ensures proper lubrication of engine components during operation. Maintaining it within range is crucial to prevent wear and overheating of moving parts.
Question- DG set tripping point due to high water temperature ?
Answer- The DG set is designed to trip when the engine water temperature reaches 95°C. This high-temperature protection prevents overheating and potential engine damage. It ensures safe operation and helps maintain engine reliability under load conditions.
Question- Name of 4 stroke ?
Answer- The four strokes in a DG set engine are Suction, Compression, Power, and Exhaust. These strokes complete one full cycle of engine operation in four piston movements. Each stroke plays a vital role in fuel intake, combustion, and expelling exhaust gases.
Question- Why prefer coolant in DG instead of water ?
Answer- Coolant is preferred over water in DG sets due to its higher boiling point and lower freezing point. It provides better thermal stability and prevents overheating or freezing in extreme conditions. This ensures efficient engine cooling and longer component life.
Question- How to calculate the efficiency of Dg Set ?
Answer- To calculate the efficiency of a DG set, divide the total energy generated in kilowatt-hours (kWh) by the amount of diesel consumed. This helps assess fuel usage and overall performance of the generator.
Efficiency = Generated kWh / Diesel consumption in liters.
Question- Types of System in DG system ?
Answer- The DG system consists of several key subsystems including the fuel system, cooling system, air intake system, lubrication system, and electrical system.
Each system plays a vital role in ensuring smooth and efficient operation of the generator.
Question- How to calculate the full load of DG set ?
Answer- FLA= KVA x 1.4 (Approximately) and for complete details pls refer to electrical formula section.
Question- What is safety of air filter of DG ?
Answer- The safety of the air filter in a DG set is monitored using a vacuum indicator. It shows the level of restriction or clogging in the air filter. This helps in timely maintenance to ensure proper airflow and engine performance.
Question- What is AVR ?
Answer- AVR stands for Automatic Voltage Regulator, which controls the output voltage of the generator. It maintains a stable voltage level despite load variations. This ensures safe and efficient operation of electrical equipment connected to the DG set.
Question- what is cranking motor/stator motor ?
Answer- The cranking motor, also known as the stator motor, is used to start the DG set engine initially. It rotates the engine's crankshaft until the engine begins running on its own. This motor plays a vital role in enabling smooth and reliable engine startup.
Question- what is governor ?
Answer- A governor in a DG set is used to control and regulate the engine speed. It maintains a constant RPM by adjusting fuel supply based on load changes. This ensures stable power output and prevents engine over-speeding.