Proper Work Area Illumination

OSHA's General Requirements (29 CFR 1926.56): "Adequate Illumination" in Practice:

• • OSHA's focus is on preventing accidents. This means that "adequate" is not just about meeting a number; it's about providing enough light for workers to:

    • Clearly see potential hazards.

    • Perform tasks accurately and safely.

    • Move safely through the work area.

  • Factors that influence "adequate" include:

    • The complexity of the task.

    • The speed of the work.

    • The presence of moving machinery.

    • The potential for falls or other injuries.

    • the color of the surfaces being worked on. Dark surfaces absorb more light, requiring more illumination.

Measurement and Monitoring:

• • Employers should use light meters (there are smartphone apps) to measure illumination levels in work areas.

  • Regular monitoring is essential, especially as site conditions change (e.g., as construction progresses, as weather conditions change, or as temporary lighting systems degrade).

  • Documentation of light level measurements is recommended for dark environments.

Breakdown of Interior and Exterior Lighting:

Interior Lighting:

• • Confined Spaces:

    • Confined spaces require meticulous lighting due to the increased risk of accidents.

    • Portable lighting is often necessary, and it must be explosion-proof if flammable materials are present.

    • Ventilation and lighting should be coordinated to prevent hazardous atmospheres.

  • Stairways and Passageways:

    • Stairways and passageways must be consistently illuminated to prevent falls.

    • Emergency lighting is critical in these areas.

    • Lighting should be placed to prevent shadows that obscure steps.

  • Areas with Dust or Fumes:

    • Lighting fixtures should be sealed to prevent dust or fumes from entering.

    • Explosion-proof lighting is necessary in areas where flammable vapors or dust are present.

Exterior Lighting:

• • Nighttime Operations:

    • Nighttime construction requires careful planning to ensure adequate illumination.

    • Floodlights and area lighting should be strategically placed to minimize shadows and provide uniform illumination.

    • Light pollution should be considered, directing light downward, and using light fixtures that prevent light from going where it is not needed.

  • Weather Conditions:

    • Rain, fog, and snow can significantly reduce visibility.

    • Lighting systems must be designed to withstand these conditions.

    • Consider using lighting with higher color rendering indexes (CRI) to improve visibility in poor weather.

  • Perimeter Lighting:

    • Perimeter lighting is essential for security and to prevent unauthorized access.

    • It also helps to ensure the safety of workers moving around the site at night.

Temporary Lighting and Power Options:

Temporary Lighting Options:

• • LED Lighting:

    • LEDs are increasingly popular due to their energy efficiency, long lifespan, and durability.

    • They also provide instant-on capability and are less susceptible to damage from vibration.

  • High-Intensity Discharge (HID) Lighting:

    • HID lights, such as metal halide and high-pressure sodium, can be used for large outdoor areas.

    • They provide high light output but require warm-up time.

  • Light Towers:

    • These are excellent for large area lighting, and can be powered by generators.

Temporary Power Options:

• • Generator Safety:

    • Proper grounding is essential to prevent electrical shock.

    • Carbon monoxide detectors should be used in areas where generators are operating.

    • Fuel storage and handling must comply with OSHA and EPA regulations.

  • Portable Power Distribution Units:

    • These units provide safe and convenient power distribution throughout the worksite.

    • They should be equipped with GFCIs and overcurrent protection.

  • Extension Cords:

    • Heavy duty extension cords should be used, and inspected regularly.

    • Cords should be protected from damage, and not be ran through doorways, or other areas where they can be damaged.

Key Considerations:

• Training: Workers should be trained on the safe use and maintenance of temporary lighting and power systems.

• Inspections: Regular inspections are vital to identify and correct potential hazards.

• Documentation: Maintain records of lighting system installations, inspections, and maintenance.

Calculate the Total Wattage of Your Lighting:

Identify the Wattage of Each Light: Check the specifications of each light fixture you plan to use. This information is usually printed on the fixture or in the manufacturer's documentation.  

Count the Number of Each Type of Light: Determine how many of each type of light you'll need.

Multiply and Add: Multiply the wattage of each type of light by the number of those lights, and then add up the totals for all your lights.

• • Example:

    • 10 LED floodlights at 100 watts each = 1000 watts

    • 20 string lights at 25 watts each = 500 watts

    • Total lighting wattage: 1500 watts

Account for Inrush Current (Starting Load):

Understand Inrush: Some lights, especially HID (high-intensity discharge) lights, require a surge of power when they are first turned on. This is called inrush current. LED lights generally have a very low inrush current.  

Factor in Inrush: If you're using HID lights, you'll need to account for this inrush current. A general rule of thumb is to multiply the running wattage of HID lights by 2 to 3 to get the starting wattage.

LED lights do not need a large multiplier.

Add a Safety Margin:

Prevent Overloading: It's essential to avoid overloading the generator. Add a safety margin of 20% to 25% to your total wattage calculation.

Example: If your total lighting wattage is 1500 watts, add a 25% safety margin (375 watts), bringing the total to 1875 watts.

Consider Other Power Needs:

Tools and Equipment: If you plan to power other tools or equipment from the same generator, add their wattage requirements to your calculation.  

Future Expansion: Consider whether you might need to add more lights or equipment in the future.

Convert Watts to Kilowatts (kW):

Divide by 1000: Divide your total wattage by 1000 to convert it to kilowatts (kW).  

Example: 1875 watts / 1000 = 1.875 kW  

Choose the Right Generator:

Generator Rating: Select a generator with a rated output that meets or exceeds your calculated kW requirement.

Running vs. Starting Watts: Pay attention to both the running watts and the starting watts of the generator. Make sure the generator can handle the starting load of any lights with inrush current.  

Fuel Type: Consider the fuel type (gasoline, diesel, propane) and the availability of fuel on the construction site.

Runtime: Determine how long you need the generator to run and choose a generator with an appropriate fuel tank capacity.  

Practical Tips:

LEDs Are Your Friend: When possible, use LED lighting to minimize power consumption and reduce the required generator size.

Use a Power Distribution Panel: A power distribution panel can help you safely and efficiently distribute power from the generator to your lighting circuits.  

Consult a Professional: If you're unsure about sizing a generator, consult with an electrician or a generator specialist.