It's crucial to establish operating standards for
diesel generators in civil buildings (such as office buildings, hotels, shopping malls, hospitals, data centers, and residential communities) to ensure safe, reliable, and efficient operation, as well as compliance with environmental and fire regulations. The following are some key elements of these operating standards:
1. Site Selection and Building Requirements
Independent Equipment Room: A separate generator room must be located. It must not be located directly above, below, or adjacent to crowded areas (such as lobbies, cafeterias, patient rooms, classrooms, or refuge floors). The equipment room must have a direct emergency exit to the outdoors.
Fire Separation: The equipment room must be separated from other areas by fire-resistant walls with a fire resistance rating of at least 2.00 hours and floors with a fire resistance rating of 1.50 hours. Doors must be Class A fire doors.
Fire Resistance Rating: The fire resistance rating of the equipment room and its surrounding structures must comply with the requirements of the "Code for Fire Protection Design of Buildings" (GB 50016).
Ventilation and Smoke Exhaust:
Air Intake: Adequate air intake must be ensured to meet the combustion and cooling requirements of the generator set. Air inlets should be located in locations with unimpeded air circulation to prevent exhaust backflow. A mechanical air intake system should be installed if necessary.
Smoke Exhaust: Smoke exhaust ducts should be constructed of non-combustible materials, installed independently, and lead to a safe outdoor area (higher than the roof or away from air inlets, doors, and windows). Due to the high exhaust temperature, thermal insulation measures are necessary. Outdoor smoke exhaust ducts should be equipped with rain caps and silencers. Fire dampers (operating temperature 280°C) must be installed where smoke exhaust ducts pass through fire walls.
Oil Storage Facilities:
Daily Fuel Tanks: Daily fuel tanks with a capacity of no more than 1 cubic meter are generally required to be installed in the machine room (specific requirements should be in accordance with local fire regulations). The tanks should be sealed and equipped with a vent pipe (with a fire arrester).
Oil Storage Room (if required): When the total oil storage volume exceeds the daily fuel tank limit, a separate oil storage room is required. The oil storage room should have a fire resistance rating of at least Class II and be separated from other areas by a fire wall. The doors should be Class A fire doors. Oil storage rooms should be equipped with features to prevent oil spills (such as thresholds and oil collection pits leading to the outside). Oil tanks should comply with relevant pressure vessel or storage tank specifications.
Flooring and Drainage: The machine room floor should be oil-resistant and non-slip, and features should be installed to prevent oil spills (such as open trenches and oil collection pits along the walls). The oil collection pit should be able to accommodate all leaks from daily fuel tanks and be connected to a safe outdoor drain or storage facility.
Noise Control: The machine room location should be designed to minimize vibration and noise, and walls, doors, and windows should be soundproofed. High-efficiency silencers should be installed on the units themselves. Silencers should be installed at outdoor smoke exhaust vents and air intakes and exhaust vents. Generator noise levels during operation should comply with the "Noise Environment Quality Standard" (GB 3096) and the requirements of the environmental impact assessment (with different limits for different areas and time periods).
Lighting and Emergency Lighting: The machine room should be equipped with both normal and emergency lighting. The duration of emergency lighting should meet operational and evacuation requirements.
II. Equipment Selection and Installation
Rated Power: The rated power of the generator set should meet the needs of all primary loads (fire pumps, fire elevators, emergency lighting, critical security systems, etc.) and critical secondary loads (such as critical office equipment, data center IT loads, and some hospital equipment), with an appropriate margin (usually 10-25%). When considering motor starting, be aware of transient inrush current.
Start-up Time: After a utility power failure, the generator set should automatically start and reach rated voltage and frequency within a set time (typically 10-30 seconds, depending on the importance of the load; critical computer systems or UPSs may require faster switching times).
Voltage and Frequency Stability: During operation, the output voltage (380V/400V ±5%) and frequency (50Hz ±1%) must remain within the specified range.
Cooling Method: Choose air or water cooling based on the actual conditions of the computer room. Water cooling systems require a reliable cooling water source (such as a high-level water tank or circulation system) and anti-freeze measures. Installation Foundation: The unit should be installed on a solid, flat concrete foundation (usually 150-200mm thick). Vibration-damping trenches or high-efficiency shock absorbers should be installed around the foundation to reduce vibration transmission.
Electrical Connections:
ATS: An automatic transfer switch should be installed to ensure safe and rapid switching between utility power and generator power (parallel operation is prohibited). The ATS should comply with relevant electrical standards and specifications.
Grounding System: The generator neutral point grounding method (usually TN-S) should be consistent with the utility power system and reliably grounded. The unit casing, control panel, and other components should be reliably grounded.
Output Power Distribution: A protective switch (main circuit breaker) should be installed at the generator output. The feeder cable cross-section must meet current-carrying capacity and voltage drop requirements.
Protection Functions: The unit control system should have comprehensive protection functions, including overcurrent protection, short-circuit protection, undervoltage protection, overvoltage protection, overfrequency protection, underfrequency protection, reverse power protection (important for parallel units), high water temperature protection, low oil pressure protection, start failure protection, and overspeed protection. Fuel Supply System: Fuel tank design, piping material (usually seamless steel or copper), and connection methods must comply with fire protection and pressure piping specifications. A reliable oil level indicator and low-level alarm must be provided. Fuel quality must meet unit requirements (e.g., national standard 0# or -10# light diesel).
III. Operational Management Standards
Startup and Shutdown:
Automatic Mode: In the event of a utility power failure, the system automatically starts, loads, and provides power. When utility power is restored, the system automatically unloads, cools, and shuts down, then switches back to utility power.
Manual Mode: Used for testing, maintenance, or emergency manual start/shutdown. Manual operations must comply with operating procedures.
Pre-Startup Inspection: (Must be performed before manual start or periodic testing) Check the lubricating oil level, coolant level, fuel level, battery voltage and connections, leaks, the unit's surrounding environment, and output switch status. Operation Monitoring:
Operating Parameters: Continuously monitor and record (manually or automatically) key parameters: output voltage, current, frequency, power, power factor, water temperature, oil pressure, speed, operating time, battery voltage, fuel level, etc.
Alarm Handling: When a control system alarm sounds, the cause must be immediately identified and addressed. Serious faults (such as high water temperature or low oil pressure) should trigger an automatic shutdown for protection.
Load Management: Avoid prolonged overload or severe underload operation (which may cause carbon deposits). When starting large motor loads, observe the starting sequence or use a soft starter/inverter.
Regular Testing and Maintenance:
Load Testing: Perform a simulated mains power outage automatic start test at full load or near full load (minimum 30% of rated load) at least monthly for at least 30 minutes (according to the equipment manufacturer's recommendations and fire safety requirements). All key parameters must be recorded during this test.
No-load/Startup Testing: Perform a no-load startup test at least weekly to verify normal startup and operation (especially for unattended or infrequently used units). Preventive Maintenance: Perform regular maintenance in strict accordance with the equipment manufacturer's maintenance manual, including but not limited to: lubricant and filter changes, coolant changes and system inspections, fuel filter changes, air filter cleaning/replacement, battery inspection and maintenance, cooling system cleaning (radiator), belt tensioning checks, electrical connection checks, control system function tests, exhaust system inspections, and complete machine cleaning. Maintain a detailed maintenance log.
Annual Inspection: It is recommended that a professional organization or manufacturer conduct a comprehensive performance inspection and maintenance each year.
Fuel Management:
Fuel Quality: Use clean diesel that meets standards. Regularly check fuel quality to prevent moisture and impurities.
Fuel Tank Management: Regularly inspect fuel tank seals, clean the tank (usually every 1-3 years, depending on the fuel quality and tank design), and regularly remove sediment from the tank bottom.
Storage Safety: Comply with safety regulations for fuel storage rooms/tanks, such as ventilation, fire prohibition, anti-static measures, and leak emergency procedures. Emergency Operating Procedures: A clear emergency operating manual should be developed and posted prominently in the equipment room. This manual should include manual start/shutdown procedures, fault alarm handling procedures, emergency shutdown procedures, and fire emergency response procedures. Relevant personnel must be familiar with this manual.
Personnel Qualifications and Training: Operators and maintenance personnel must receive professional training to understand the equipment's operating principles, operating procedures, safety precautions, and maintenance requirements. They must hold a certification (if local regulations require this).
IV. Environmental Standards
Exhaust Emissions: Exhaust gases (including NOx, CO, HC, PM, etc.) generated by the unit during operation must comply with the latest national and local pollutant emission standards (e.g., "Exhaust Pollutant Emission Limits and Measurement Methods for Diesel Engines for Non-road Mobile Machinery" GB 20891 and its subsequent revisions, or local standards). New projects should particularly adhere to the most stringent National IV standards or future higher standards. Exhaust after-treatment devices (such as DPFs and SCRs) should be installed as necessary. Noise Emissions: When the unit is operating, noise levels at designated measurement points (e.g., 1 meter outside the machine room window, 1 meter outside residential windows, and at the factory boundary) must comply with the "Noise Environment Quality Standard" (GB 3096) and relevant environmental impact assessment approval requirements.
Oil Waste Disposal: Waste lubricating oil and used filter cartridges should be collected and stored in accordance with hazardous waste management regulations and handed over to qualified personnel for disposal. Disposal is prohibited. Emergency spill materials such as oil absorbent cotton and sand should be available in the machine room.
V. Fire Protection Requirements
Fire Extinguishing System: The generator room must be equipped with appropriate automatic fire extinguishing devices. Commonly used devices include:
Gas fire extinguishing systems: Clean gases such as IG-541 and HFC-227ea are suitable for protecting electrical equipment.
High-pressure water mist fire extinguishing systems: Water-saving and highly effective, they can also be used for electrical fires.
Automatic sprinkler systems: The impact of water damage on electrical equipment must be carefully evaluated and used only under specific conditions or as a supplementary measure. The use of automatic foam or dry powder systems is strictly prohibited (they may damage equipment). Specific selection should comply with the "Code for Fire Protection Design of Buildings" (GB 50016) and relevant fire protection technical standards.
Fire Alarm: Independent heat and smoke detectors should be installed in the computer room and connected to the building's automatic fire alarm system.
Fire Extinguishing Equipment: A sufficient number of portable carbon dioxide or dry powder fire extinguishers (for combined oil and electricity fires) should be readily available at the computer room entrance and within the computer room.
Interlocking Control: When a fire alarm sounds in the computer room, the ventilation system and fuel supply valve (if feasible) should be automatically shut down. The ventilation system should also be automatically shut down before the gas fire extinguishing system is activated.
Summary:
The operating standards for diesel generators in civil buildings are a comprehensive system encompassing site selection, design, installation, equipment performance, operation, maintenance, safety, and environmental protection. Strict implementation of these standards is fundamental to ensuring the safe, reliable, and timely operation of the backup power system at critical moments, protecting life and property, and preventing environmental pollution and noise nuisance. Detailed implementation must be based on the specific regulations and requirements of the fire and environmental protection departments in the specific project location. We recommend consulting a professional electromechanical design institute, generator supplier, and local authorities.
