Enclosure Selection Table 110.28 is an essential tool used in electrical engineering to guide professionals in selecting the appropriate enclosures for electrical equipment based on environmental conditions.
The table helps ensure that electrical enclosures provide adequate protection against environmental factors such as moisture, dust, corrosive agents, and more.
Enclosure Selection Table 110.28 Calculator
Enclosure Selection Table 110.28
Enclosure Types (Numbers and Letters):
- Type 1, 2, 3, 3R, 3S, 4, 4X, 5, 6, 6P, 7, 9, 12, 12K, 13: These numbers and letters refer to the NEMA (National Electrical Manufacturers Association) enclosure types. Each type is rated for specific environmental conditions, such as dust, water, and corrosion resistance. Here’s a brief explanation of some common types:
- Type 1: For indoor use, primarily to provide a degree of protection against limited amounts of falling dirt.
- Type 3: For outdoor use, providing protection against windblown dust, rain, sleet, and ice.
- Type 4: For indoor or outdoor use, providing protection against windblown dust, rain, splashing water, and hose-directed water.
- Type 4X: Similar to Type 4 but with additional corrosion resistance.
- Type 6: For indoor or outdoor use, providing protection against temporary submersion in water.
- Type 6P: Similar to Type 6 but suitable for prolonged submersion.
- Type 12: For indoor use, providing protection against circulating dust and falling dirt.
- Type 13: For indoor use, providing protection against dust, spraying of water, oil, and non-corrosive coolants.
How to Use Enclosure Selection Table 110.28
This table is divided into two main sections: one for outdoor use and another for indoor use.
Each section lists different environmental conditions and indicates which enclosure types provide protection against those conditions.
Step 1: Determine the Environment
The first step in using the table is to identify the environment where the electrical equipment will be installed.
Is the equipment located outdoors, exposed to the elements, or indoors in a controlled environment? The table separates these scenarios to help you choose the right enclosure.
Step 2: Identify the Environmental Conditions
Next, you need to determine the specific environmental conditions the enclosure needs to protect against. These conditions can include:
- Incidental Contact with the enclosed equipment
- Rain, Snow, and Sleet
- Windblown Dust
- Hosedown and Splashing Water
- Corrosive Agents
- Temporary or Prolonged Submersion in water
- Falling Dirt or Liquids
- Oil or Coolant Spraying and Seepage
Each of these conditions requires a different level of protection, which is provided by specific enclosure types.
Step 3: Select the Enclosure Type
Once the environmental conditions are identified, refer to the appropriate section of the table (outdoor or indoor).
The table lists various enclosure types (e.g., 1, 3R, 4X, 6P, 12K) and marks them with an “X” to indicate which conditions they protect against.
For example:
- Outdoor Use:
- If the equipment is exposed to rain, snow, and sleet, you might choose enclosure types 3R, 4, or 6P.
- If the equipment is subjected to corrosive agents, enclosure types 4X or 6P would be suitable.
- Indoor Use:
- For protection against falling dirt and circulating dust, you might select enclosure types 12, 12K, or 13.
- If the equipment needs protection against oil or coolant spraying and splashing, an enclosure type 13 would be necessary.
Examples of Enclosure Type Usage
Example 1: Outdoor Use – Industrial Plant An industrial plant with outdoor electrical panels exposed to rain, wind, and corrosive chemicals would require an enclosure that can withstand these harsh conditions.
Enclosure types 4X or 6P would be ideal for this situation, as they offer protection against water ingress, dust, and corrosive agents.
Example 2: Indoor Use – Factory Floor On a factory floor where machinery is operating, the environment may involve falling dirt, dust, and light splashing of liquids.
In this case, an enclosure type 12 or 12K would provide sufficient protection to keep the equipment safe from these contaminants.
Example 3: Underground Facility In an underground facility where electrical equipment might be temporarily submerged in water, enclosure type 6P is the most appropriate choice as it offers protection against both temporary and prolonged submersion.
Importance of Using the Correct Enclosure Type
Choosing the correct enclosure type is crucial for ensuring the longevity and safe operation of electrical equipment.
The right enclosure prevents environmental conditions from damaging the equipment, which could lead to electrical failures, increased maintenance costs, or even hazardous situations.