05 November 2024
Raising The Bar Guidance - Diesel Generator Below 20KVA Equipment Requirements
Diesel generators under 20KVA are compact, portable power sources used on construction and highway sites to support smaller equipment, lighting, and mobile offices, especially in areas without a stable electricity supply. Their portability and lower fuel consumption make them ideal for smaller-scale or temporary power needs. However, diesel generators below 20KVA also require careful handling due to fuel storage requirements, exhaust emissions, and noise levels. The National Highways "Raising the Bar 1" guidelines outline key safety and operational standards to ensure the safe, compliant use of diesel generators below 20KVA on all projects.
General Minimum Requirements
The General Minimum Requirements (GMR) provide baseline safety and operational standards for all equipment, including diesel generators below 20KVA:
Daily Inspections: Small diesel generators must undergo thorough pre-use inspections each day. Operators should check for potential issues such as fuel or oil leaks, proper functioning of controls, emergency shutdown features, and battery charge status if the generator uses a battery starter.
Compliance with Legislation: Diesel generators must meet UK regulatory standards, including UKCA certification and compliance with the European Commission Machinery Directive (2006/42/EC). Environmental compliance, such as adherence to Stage V emissions standards, is also recommended to minimize air pollution.
Safety Decals and High-Visibility Markings: Safety decals should be visible and legible around access points, control panels, and fuel compartments. High-visibility markings must also be applied to any steps, handles, or external connectors for safe handling.
Secure Fuel Storage and Handling: All fuel containers should be stored in secondary containment, such as bunds or trays, to prevent spills or leaks that could lead to environmental contamination.
Noise Control Measures: Small diesel generators can generate significant noise, particularly in urban settings. Noise control measures, such as using sound-dampening enclosures, should be implemented to reduce noise pollution.
Equipment-Specific Safety and Compliance Standards
Given the fuel handling requirements, emissions, and potential for noise output, diesel generators below 20KVA require additional safety standards to ensure safe operations:
Emergency Shutdown System: Diesel generators must be equipped with an emergency shutdown system to allow for an immediate stop in case of an emergency, such as a fuel leak or overheating.
Automatic Voltage and Load Management: Small generators should have automatic voltage and load monitoring to prevent overloads, which could cause malfunction or pose a fire risk.
Exhaust and Emissions Control: Generators should be positioned with exhaust vents directed away from workers or sensitive areas. Compliance with Stage V emissions standards is recommended to reduce harmful pollutants.
Fuel Security and Locking Mechanisms: Fuel tanks and filler caps should be securely locked to prevent unauthorized access, tampering, or fuel theft.
Spill Kits and Containment: A spill kit should be readily available near the generator for managing any accidental spills or leaks. Fuel storage and containment should comply with environmental protection standards to minimize contamination risks.
Fire Extinguishers: A suitable fire extinguisher should be available close to the generator to quickly address any fires, particularly those related to fuel or electrical faults.
Power Supply, Load Management, and Operational Standards
The power generation capacity of diesel generators below 20KVA requires specific standards for load management, fuel handling, and safe operation:
Controlled Load Distribution: Operators should manage load distribution carefully to avoid overloading the generator. For prolonged use, automatic load balancing systems are recommended to maintain stable power supply and avoid wear.
Fuel Storage and Refuelling Protocol: Fuel storage should be located away from the generator exhaust to prevent overheating. Refuelling must only take place when the generator is shut down and cooled, with appropriate PPE worn by the operator.
Grounding and Earthing Connections: Proper grounding of the generator is essential to prevent electrical hazards, especially in wet or outdoor environments. Earth connections should be checked daily to ensure a safe, stable operation.
Distance from Flammable Materials: Generators must be positioned at a safe distance from flammable or combustible materials. Barriers should be installed as necessary to restrict access and prevent contact with nearby personnel.
Regular Oil and Filter Changes: Routine maintenance, including oil and filter changes, helps ensure consistent performance, reduce emissions, and prevent premature wear.
Exclusion Zones Around Generator: Establishing an exclusion zone around the generator reduces the risk of accidental contact and limits access to authorized personnel, particularly during refuelling or maintenance.
Operator Competency and Requirements
Operating diesel generators below 20KVA requires trained operators skilled in load management, fuel handling, and safety procedures. The following standards apply:
Licensing and Certification: Operators must have appropriate certifications for handling small generators, including fuel handling and power load management.
Generator-Specific Training: Operators should receive training specific to the generator model they are using, covering operation, load management, refuelling, and emergency shutdown procedures.
Understanding of Load Capacity and Distribution: Operators should understand how varying loads impact generator performance and the importance of avoiding overloading, particularly during extended operation.
Safe System of Work: Operators should be briefed on the site’s Safe System of Work (SSoW) and sign onto the Plant, Vehicle, and People Management Plan (PVPMP) for each specific worksite.
Emergency Response Procedures: Operators must be trained in emergency shutdown, spill management, and fire containment protocols, with familiarity in using spill kits and fire extinguishers as needed.
Desirable Features
Additional features are recommended to improve safety, efficiency, and environmental compliance for diesel generators below 20KVA:
Automatic Load Monitoring System: An automatic load monitoring system helps prevent overloads and ensures efficient power distribution across connected devices.
Stage V Emission Compliance: To reduce environmental impact, Stage V-compliant engines are recommended, particularly for use in urban or environmentally sensitive areas.
Sound-Dampening Enclosure: A sound-dampening enclosure can significantly reduce noise levels, making the generator more suitable for use in noise-sensitive areas.
Fuel Level and Usage Monitoring: A fuel monitoring system provides real-time feedback on fuel levels, allowing operators to schedule refuelling proactively and avoid interruptions.
Automatic Shutdown for Overload or Overheat: Automatic shutdown on overload or overheating conditions reduces the risk of damage to the generator and connected equipment.
Remote Monitoring Capability: Remote monitoring features allow operators to track generator performance, fuel levels, and load distribution from a distance, adding flexibility for managing multiple power sources on a large site.
Hazard Identification and Mitigation
Operating a diesel generator below 20KVA involves specific hazards, and hazard mitigation is essential for safe operation:
Fuel and Fire Hazards: The presence of diesel fuel introduces fire and spill risks. Secure fuel storage, readily available spill kits, and fire extinguishers help mitigate these hazards.
Overload and Electrical Risks: Overloading the generator can cause electrical faults or fires. Load monitoring systems and proper grounding help prevent overloads and reduce electrical risks.
Noise and Vibration Exposure: Small generators still generate noise and vibrations that can impact operator health. Operators should use hearing protection, and sound-dampening enclosures are recommended to reduce noise impact.
Emissions and Air Quality Concerns: Diesel generators produce exhaust emissions that can impact air quality. Compliance with Stage V emissions standards helps reduce the generator’s environmental footprint.
Unauthorized Access and Fuel Security: Secure locking mechanisms for fuel tanks and filler caps prevent unauthorized access and potential tampering or fuel theft.
Oil and Hydraulic Fluid Leaks: Routine maintenance helps prevent leaks, reducing the risk of environmental contamination and ensuring reliable operation.
Summary
The Diesel Generator Below 20KVA is a reliable, portable power source suitable for small to medium-scale needs on construction and highway projects. However, due to fuel handling, noise levels, and potential emissions, strict adherence to National Highways' "Raising the Bar 1" guidelines is essential. By following protocols for daily inspections, load management, refuelling safety, and emissions control, operators and site managers can ensure the safe and effective use of small diesel generators. Additional features, such as sound-dampening enclosures, automatic load monitoring, and remote monitoring, further enhance operational safety, efficiency, and environmental responsibility.
This article provides a comprehensive overview of the safety standards, operator requirements, and hazard management strategies for diesel generators below 20KVA, ensuring compliance with National Highways’ standards for safe and efficient project execution.