The NEC (National Electrical Code) doesn't specify a specific height above an engine for vapor-proof lights. The requirement is more general and focused on hazard classification.Here's the breakdown:1. Determine if the area is classified

The key is whether the area above the engine is classified as a hazardous location (e.g., Class I Division 1 or 2, Class II Division 1 or 2). This depends on the potential for flammable vapors, gases, or combustible dusts to be present.2.

Hazardous Location Requirements

If the area is classified as hazardous, you

must install lighting fixtures approved for that specific classification. This likely means vapor-tight/vapor-proof fixtures designed for the appropriate Class, Division, and Group. The height depends on the zone of the hazard. Think of it as a three dimensional space. You'll need to determine how far the hazardous vapor/dust may travel and install the light fixture beyond that zone.3. If NO Hazardous Classification

If the area is not classified as hazardous (meaning there's no reasonable expectation of flammable vapors, gases, or dusts), then the height becomes a matter of good engineering practice. You need to consider:

Accessibility for Maintenance

Can you easily reach the lights for bulb changes and cleaning?

Illumination

Are the lights providing adequate light for the tasks being performed in the area?

Physical Protection

Are the lights protected from damage from moving equipment, tools, or personnel?

Ambient Conditions

Engine areas can be hot. Are the fixtures rated for the ambient temperature they'll experience?

In summary



Hazardous Location

Follow the NEC for hazardous locations. The code defines the requirements.

Not a Hazardous Location

No specific height dictated by the NEC. Consider accessibility, illumination, protection, and ambient conditions.

Important Considerations



Consult the NEC

You must consult the latest version of the National Electrical Code (NEC) for the most up-to-date and precise requirements. Article 500 and the associated articles (501, 502, etc.) are critical for hazardous locations.

Local Codes and Regulations

Check your local building codes and regulations. They may have additional requirements that go beyond the NEC.

Qualified Electrician

This is not a DIY project. A qualified and licensed electrician is essential for properly classifying the area, selecting the appropriate lighting fixtures, and installing them safely and according to code.

Area Classification Documentation

The owner or operator of the facility is typically responsible for the area classification, based on their knowledge of the processes and materials present. This classification should be documented.*

Vapor-Proof Lighting vs. Vapor-Tight Lighting There are differences between vapor-proof and vapor-tight. Vapor-proof are made for explosive or flammable vapors. Vapor-tight is typically used for wet locations and not rated to contain an explosion.Without knowing if you are dealing with a hazardous classified area, there is no minimum height. Flag for review