Custom Machined Enclosures: Essential Guide to Design and Applications
- Gavin Leo
Custom-machined enclosures are protective barriers that protect electronic devices and components from harmful elements such as dust, moisture, and electromagnetic interference.
Custom-machined enclosures are designed from scratch, which helps manufacturers address specific environmental conditions or complex component layouts.
Additionally, custom-machined enclosures are different from standard enclosures. Standard enclosures have a generic layout and are intended to cover various applications. Custom-machined enclosures, however, are made to meet unique buyer or application requirements.
In this guide, you’ll learn everything about custom-machined enclosures, from types of enclosures and manufacturing processes to material selection and range of applications.
Types Of Enclosures
You must choose an enclosure type that performs well and protects your equipment. Two commonly used enclosure types are:
NEMA Enclosures
The National Electrical Manufacturers Association (NEMA) has defined enclosure standards that protect against environmental risks such as water, dust, and corrosive agents.
NEMA enclosures are categorised into two types (e.g., NEMA 4, NEMA 12). Both enclosure types are tailored for specific conditions:
NEMA 4: This nema enclosure type is dedicated to outdoor applications, offering safety against dust, rain, or water.
NEMA 12: This type of NEMA enclosure is designed for indoor use and protects against dust, dirt, and non-corrosive liquids in industrial environments.
For example, a NEMA 4X stainless steel enclosure is frequently used in chemical plants due to its resistance to corrosive substances and ability to withstand washdowns.
IP Enclosures
Ingress Protection (IP) ratings have classified enclosures based on dust and water ingress resistance. Ratings such as IP65 or IP67 show the degree of protection provided:
IP65: These are dust-tightened enclosures that protect against low-pressure water jets.
IP67: These enclosures provide complete dust protection and can withstand temporary submersion in water.
For example, an IP67-rated aluminium enclosure is perfect for outdoor telecommunications equipment, where exposure to rain and dust is unavoidable.
IECEX Enclosures
IECEx enclosures meet international standards for use in hazardous areas with explosive atmospheres, such as oil refineries or mining operations. They control internal sparks and heat inside the enclosure so that they do not cause fires.
IECEx-certified enclosures extend across offshore drilling rigs because they operate within environments containing flammable gases.
ATEX Enclosures
ATEX enclosures also meet the European Union’s safety standards for explosive atmospheres. They are helpful in the petrochemical and pharmaceutical manufacturing industries.
For example, storage facilities containing volatile chemicals use ATEX-approved enclosures to protect against operational safety needs.
UL Listed Enclosures
Underwriters Laboratories (UL) tests and certifies enclosures to ensure compliance with North American security protocols. UL-listed enclosures are designed to meet electrical safety and fire resistance requirements.
For example, industrial control panels rely on UL 508A enclosures to ensure factory compliance with electrical codes.
Manufacturing Custom Enclosures
Custom enclosure production is a complex operational procedure that requires skilled workers, detailed preparations, and exact execution methods. It involves several steps over a long time frame.
The production team ensures that the final product meets the customer’s specifications and needs.
#1 Concept Development and Design
Understanding the project’s requirements is the first step in manufacturing custom-machined enclosures. The engineering team works with customers to manage all aspects of the design parameters.
The process generates a detailed model as engineers build the concept according to what the custom enclosure needs to accommodate in targeted applications, environmental conditions and equipment specifications.
Computer-aided design (CAD) software is pivotal in completing this work. With advanced CAD tools, designers create three-dimensional models for custom enclosures.
These models incorporate all customer-required features, such as cutouts, mounting holes, and mating parts (parts that join together seamlessly during assembly).
Potential Obstacles: Design engineers must also account for thermal management, electromagnetic interference (EMI), and ingress protection (IP ratings).
This ensures that the custom enclosure can ensure the safety of sensitive electronics while prioritising operation efficiency.
For example, if the custom enclosure is intended for outdoor use, the design might include weatherproof seals, protective coatings, and drainage holes to prevent water accumulation.
#2 Material Selection and Fabrication
After completing the design of the customised enclosure, the next step is to select the fabrication materials. The selection of materials determines multiple aspects of enclosure performance, including its endurance, weight, and manufacturing expenses.
Custom enclosure manufacturers select aluminium or stainless/carbon steel as their primary material based on the requirements of their particular application. Sheet metal is the primary choice for enclosure fabrication due to its flexible fabrication process.
Fabrication usually includes:
CNC Machining: CNC machining is intensively beneficial for custom electrical enclosures, delivering precise dimensions and detailed elements that meet strict tolerance requirements.
Sheet Metal Fabrication: Metal sheets are cut, bent, and formed to create the custom enclosure. This method benefits large production applications. It sacrifices product quality, but modern machinery and skilled operators eliminate that drawback.
Cutouts and Holes: During fabrication, ventilation cutouts, mounting holes, and access panels are integrated to provide space for wiring and component installation.
Stainless steel meets NEMA rating requirements due to its corrosion-resistant properties. However, CNC machining delivers perfectly fitting doors and panels that meet established environmental standards.
#3 Finishing and Assembly
The completion process integrates surface finish treatments with custom enclosure assembly.
Custom enclosures benefit from surface treatments that provide aesthetic quality and protection against external influences such as corrosion and wear.
Depending on their material choice, industry professionals can choose various finishing options, such as powder coating, anodising, and passivation.
A completed custom enclosure is ready when gaskets, locks, and hinges are assembled into the custom enclosure formation to reach operational status.
Quality control remains essential at this stage of operation. The checks during inspections ensure the custom enclosure satisfies every aspect of customer requirements, including precise measurements of physical stability and surface finishing levels.
For example, industrial control cabinets receive powder coating to increase their durability through superior adhesive capabilities. At the same time, high-precision assembly ensures that the custom enclosure maintains resistance to harsh operating conditions.
Material Selection For Custom Enclosures
Stainless Steel
Manufacturers use stainless steel as the prime material for custom electrical enclosures because it is highly resistant to corrosion and durable in demanding operational settings.
This material serves manufacturers because it combines strength with resilience against harsh settings while maintaining product quality.
It is highly resistant to rust and moisture and can function across extreme temperatures. This material’s strength maintains electrical equipment’s safety while operating in potentially hazardous industrial locations.
Properties of this material include:
Corrosion Resistance: Withstands exposure to moisture, chemicals, and salt.
Strength: Provides superior mechanical performance.
Weight: Heavier than aluminium, which increases structural stability for installations remaining in one location.
Heat Resistance: Maintains solid structural properties when exposed to intense heat, making it perfect for industrial environments.
The advantages of stainless steel are:
High tensile strength allows for thinner walls without sacrificing durability.
Corrosion resistance ensures longevity, even in saltwater, acid, or alkaline environments.
Suitable for custom enclosures such as NEMA 4X or IP67, which require high protection.
Even though it’s relatively expensive compared to other materials like carbon steel, its exceptional longevity and minimal upkeep requirements save money in the long term.
Specific Grades include:
304 Stainless Steel is the most commonly used grade due to its excellent corrosion resistance and affordability. It is suitable for indoor and outdoor applications, including food processing and medical equipment.
316 Stainless Steel: Stainless Steel Grade 316 is highly resistant to chloride and corrosive chemicals, making it suitable for marine applications and chemical production facilities.
For example, A 316 stainless steel NEMA enclosure prevents corrosion in oil rig structures operating in seawater conditions.
Aluminum
Aluminium is used in custom enclosures for lightweight production and superior heat management. This material works well across many electronics systems and industrial installation needs.
Aluminium’s lightweight and heat-conducting properties make it ideal for heat-dissipating custom enclosures. These enclosures need lightweight designs similar to air-based and wall-mounted electrical setups.
Properties include:
Weight: Lightweight compared to stainless steel, reducing installation challenges.
Corrosion Resistance: Naturally resistant to oxidation, anodising enhances this property.
Thermal Conductivity: Dissipates heat efficiently, protecting internal components.
Formability: Easy to shape into complex designs, accommodating unique enclosure specifications.
The advantages of aluminium are:
Lightweight, making it easier to transport and install.
High corrosion resistance, especially when anodised, ensures durability in outdoor settings.
Excellent thermal conductivity helps dissipate heat, protecting internal components.
Non-magnetic properties make it suitable for sensitive electronics.
Additionally, aluminium is more affordable than stainless steel, especially for volume production. It is a less costly solution for projects requiring high-performance materials without compromising quality.
Specific grades include:
6061 Aluminum is widely used in aerospace and electronics because it is known for its exceptional strength and corrosion resistance.
5052 Aluminum: This grade offers excellent formability and resistance to saltwater, making it ideal for marine and outdoor applications.
For example, a 5052 aluminum IP67 enclosure is an ideal solution for outdoor telecommunications equipment, where lightweight construction and resistance to moisture are critical.
By selecting the right material, manufacturers can optimise the customisation of enclosures to accommodate different industries’ requirements. Both options provide reliable solutions for engineering teams looking to create high-quality enclosures tailored to specific needs.
Surface Finishes For Custom Enclosures
Surface finishes enhance the durability, aesthetics, and functionality of custom-machined enclosures. They protect against corrosion and safeguard against wear and environmental damage.
Additionally, they improve the appearance and quality of custom enclosures. The following represents standard finish options that manufacturers use during custom enclosure production. Each offers unique benefits for specific applications.
Powder Coating
Powder coating is a popular finishing method for custom electrical enclosures due to its durability and versatility. This process involves applying a dry powder, usually polymer resin, to the enclosure’s surface. The enclosure is heated to cure the powder and create a protective finish.
Benefits include:
Provides a high level of protection against scratches, corrosion, and UV radiation.
The coating provides diverse color schemes and texture options, allowing manufacturers to deliver enclosures that fulfill particular design demands.
Suitable for both indoor and outdoor applications, including industrial control panels and telecommunications cabinets.
For example, NEMA-rated enclosures with powder coating can withstand extreme weather conditions and chemical exposure, making them suitable for industrial automation and off-the-shelf enclosure applications.
Chem-film
Chem-film, also known as chromate conversion coating, is a chemical process used to improve the corrosion resistance of aluminium enclosures while maintaining conductivity.
Benefits include:
It is ideal for electronics requiring an electrically conductive surface without compromising protection.
Provides a uniform finish, ensuring custom machined enclosures meet precise specifications.
For example, chem-film is commonly applied to 5052 aluminum enclosures, offering a great solution to electrical conductivity and corrosion resistance in aerospace applications.
Anodising
Anodising is a finishing process that enhances the surface hardness and corrosion resistance of aluminium enclosures. It creates a protective oxide layer on the material’s surface, providing long-lasting protection while maintaining its aesthetic appeal.
Its benefits are:
Increases durability and resistance to scratches.
Available in various colours, allowing manufacturers to create enclosures with customisable aesthetics.
Lightweight yet durable, anodised aluminum enclosures suit electronics and outdoor applications.
For example, medical equipment often uses an anodised 6061 aluminum enclosure to ensure a durable and easy-to-clean surface.
Passivation
Passivation enhances the corrosion resistance of stainless steel enclosures by creating a chemically passive layer that removes surface impurities. This layer protects the enclosure from rust and oxidation.
Its benefits include:
Ensures stainless steel enclosures retain high corrosion resistance, even in harsh environments.
It prevents contamination, making it ideal for enclosures used in food processing and pharmaceutical industries.
Extends the life of the enclosure without sacrificing product quality.
For example, passivated 316 stainless steel NEMA enclosures are commonly used in marine environments, where exposure to saltwater poses significant corrosion risks.
Whether your project involves outdoor applications, industrial cabinets, or custom electrical enclosures, choosing the right surface finish ensures your enclosure delivers maximum protection and durability.
Manufacturers must collaborate with their engineering team to assess the enclosure’s intended use and select a finish that aligns with customer specifications and operational requirements.
Design Guide For Custom Machined Enclosures
Designing custom-machined enclosures involves a detailed process to ensure the final product meets the application’s needs while offering reliable protection for internal components.
A successful design incorporates functionality, aesthetics, and compliance with industry standards to create quality products.
Understand Application Requirements
First, you must clearly define what your custom enclosure requires. This ensures the enclosure satisfies all components and fits seamlessly into its chosen environment.
Some key factors to address are:
Environmental exposure: You must decide whether to install the custom enclosure indoors or outdoors. NEMA enclosures for outdoor use may require additional coatings to withstand bad weather.
Mounting needs: Plan to secure the enclosure to walls, poles, or equipment by drilling holes or using brackets.
Heat dissipation: Include ventilation cutouts or integrate heat sinks for electronics that generate significant heat.
For example, when designing a custom IP67-rated enclosure for outdoor telecommunications, you must add gaskets and ensure that water does not seep into the building.
Leverage Advanced Tools and Prototyping
Computer-aided design (CAD) tools can help you create precise models of your custom enclosure. CAD lets you visualise the enclosure, imitate potential stress points, and note down features like doors, latches, and ventilation.
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CAD allows you to create 3D designs, which allows you to see how all components will fit and identify potential obstacles.
Develop prototypes using CNC machining or 3D printing to test the design’s feasibility before moving to full-scale production.
For example, a CAD simulation can help ensure the enclosure door aligns perfectly with mating parts, preventing issues during assembly.
Ensure Compliance with Standards
You must ensure that your electrical enclosure complies with industry standards. To do this, you can:
Review standards side by side during the design phase to avoid costly redesigns later on.
Work with a trusted partner who is an expert in regulatory compliance.
These measures help create an enclosure design that satisfies all standards.
Account for Manufacturing Constraints
You must work with your engineering team and manufacturing partners to optimise your design. Additionally, you must also address material availability, tooling limitations, and production timelines to avoid delays.
Some tips are:
Choose readily available materials, such as 6061 aluminum or 304 stainless steel, to minimise lead times.
Simplify designs where possible to reduce complexity and cost.
For example, simplifying an enclosure’s design by reducing unnecessary features can shorten the lead time without sacrificing performance.
Optimise for Customization
The ability to customize is a great advantage of custom enclosures. Designers can follow these steps for customization:
Cutouts: Plan for cutouts to accommodate connectors, switches, or displays.
Custom Shapes: Use materials like sheet metal to create unique shapes that accommodate specific equipment.
Surface Finishes: Factor in finishing processes like anodizing or powder coating during the design stage.
For example, the customization of a 5052 aluminum enclosure ensures the addition of cutouts for ventilation, which can protect internal components while ensuring heat is released effectively.
Optimise for Customization
A well-designed enclosure should guarantee strong protection for sensitive electronics. Consider:
Reinforcing structural components for enclosures used in industrial or hazardous indoor environments.
Using corrosion-resistant materials and finishes for enclosures exposed to moisture or chemicals.
For example, enclosures used in the food business are durable even after frequent washing and harsh cleaning.
Common Applications
Various sectors depend heavily on customized machine-made enclosures for precise operational and environmental requirements. Here are the most significant applications:
Industrial Automation
Industrial facilities use custom enclosures to protect control panels, PLC systems, and industrial wiring from environmental factors, such as dust, water, and mechanical damage.
Additionally, manufacturing plants utilize NEMA-rated custom enclosures to safeguard equipment from rainwater immersion while stabilizing it during vibrational movements and oil encounters.
Telecommunications
Enclosures maintain servers, network switches and routers within telecommunications systems. These containment structures incorporate air circulation mechanisms and waterproofing elements for external deployments.
For instance, an IP67 aluminum enclosure acts as an outdoor cell tower protection system, shielding equipment from rain and dirt exposure.
Healthcare Equipment
Medical devices need durable, sterile protective assemblies. Aluminum is the perfect choice for these assemblies because it offers superior hygiene and corrosion resistance.
For example, a powder-coated enclosure used in MRI machines protects internal electronics from electromagnetic interference and supports easy cleaning.
Renewable Energy
Custom enclosures are vital in renewable energy systems for protecting inverters, batteries, and control systems in solar and wind energy setups.
For example, a passivated stainless steel enclosure ensures longevity in offshore wind turbines exposed to harsh marine conditions.
Hazardous Environments
Industries like petrochemical and mining depend on ATEX and IECEx-certified enclosures to prevent sparks and protect against explosions in volatile environments.
For example, oil refineries use an ATEX-approved enclosure to indoor house electrical systems safely in the presence of flammable gases.
FAQs
Why are electrical enclosures so expensive?
The high cost of electrical enclosures results from using premium materials like aluminum, precise CNC machining, and compliance with standards like NEMA or UL. However, customization, protective finishes, and durability make them a long-term investment.
What are the three types of electrical cable enclosures?
NEMA Enclosures: Barrier against dust and moisture, ideal for industrial and outdoor use.
IP Enclosures: Rated for dust and water resistance, such as IP67 for temporary submersion.
UL Listed Enclosures: Ensure electrical safety and fire resistance in industrial settings.
What is the best material for an enclosure?
Stainless steel is the best solution for corrosion resistance, aluminum for lightweight and thermal efficiency, and sheet metal for cost-effective, simpler designs.