Questions You Should Know about Custom Enclosure Solutions

How long does it take to build an enclosure?

Please visit our website for more information on this topic.

We manufacture custom sheet metal electronic enclosures, mounting hardware, and miscellaneous components. We start from your design, and build them in 2-3 days, with no minimum order requirements. Extra lead time may be required for use of non-stocked components or materials, large quantity orders or for silkscreening (due to drying time). If time is critical for your job, be sure to discuss it with your account manager, and we can review your design to determine the lead time, and suggest workarounds for any design elements that may result in delays.

What types of enclosures can you manufacture?

We build sheet metal enclosures from your design within 2-3 days. We can build many different kinds of enclosures, including rackmount, U-Shape, L-Shape, consolets, machined enclosures, hybrid enclosures, custom computer enclosures, extruded aluminum, as well as panels, brackets and copper bus bars. View our Electronics Enclosures page for full details.

I need my enclosure right away. It's not a standard shape and has some unusual cutouts. How fast can you deliver?

Most enclosures are typically shipped within 2-3 business days after the client has approved the design, regardless of level of customization or complexity. However, extra lead time may be required for use of non-stocked components or materials, large quantity orders or for silkscreening (due to drying time). If time is critical for your job, be sure to contact us, and we can review your design to determine the leadtime, and suggest workarounds for any design elements that may result in delays.

What does it mean for an enclosure to be 1U?

o 1U (1.73") is a standard rack enclosure height. It refers to the height of the front panel and also dictates the location of the front panel mounting holes. The following table shows the front panel height for the various standards.

StandardNominal Front Panel height 1U1.75 in 2U3.50 in 3U5.25 in 4U7.00 in 5U8.75 in 6U10.50 in 7U12.25 in

For U-Shape enclosure templates, does the width include the thickness of the cover or is it just the width of the base?

The U-shape template dimensions are for the width, depth and height of the base only (doesn't include cover thickness).

Are there limitations on the shape of the enclosure?

We can manufacture all the common enclosure styles, and when it comes to fully custom designs, we have an enormous amount of flexibility. We use toolless cutting techniques, so any shape may be cut. The main limitation is in bending. Press brakes can do straight-line bends only. There are few limitations on the first bend on a part, but elements of the part may interfere with subsequent bends. Our Fabrication Tolerances page has full details, including a PDF with bend tolerance diagrams. If you have additional questions, please contact us.

What is the biggest part you can manufacture?

It depends on the geometry of the enclosure. The main limitations are 4' x 8' (1220mm x 2440mm) limitation imposed by our standard sheet metal stock, and a 6' (1830 mm) bend length limitation imposed by press brake equipment, or a 10' (3048 mm) bend limitation imposed by the folder.

What is the smallest enclosure you can manufacture?

It all depends on the design. With CNC machining, we are capable of manufacturing very small enclosures, as small as 1 x 1 x 0.5. We recommend contacting us about your design so that we can discuss it.

Are there any restrictions on the shapes and sizes of cutouts?

There are virtually no restrictions. We can cut almost any shape or size cutout provided it fits within our enclosure size limitations.

Is there a maximum number of cutouts you can do per side?

There is no limit to the number of cutouts. As a rule of thumb, cutouts should be no closer than 1.5 x metal thickness from another cut, although there is some leeway in practice. Also, parts with a very large number of cutouts may warp from heat and/or relief of residual stresses inside the metal. Contact us if you encounter either situation arises when designing.

I was told my enclosure should be made of 16 ga steel. What does this mean?

ga., or Gauge, refers to the thickness of the material being used. There are a number of gauges, each of which is specific to the type of material in question, so an actual thickness specification (in inch or millimeter units) leaves less room for error. See the Materials, Components, and Finishes page for more information, including standard stocked gauges. Choose the material you'd like to use for your design from the menu on the left-hand side of the page.

Can you manufacture NEMA-rated enclosures?

We can build your design to your specifications, however we cannot certify our enclosures as NEMA-rated. Contact us with your needs, and we will work with you to build an enclosure that meets the standards required.

Can I get an IP rated enclosure?

Technically, we cannot provide you a certified IP-rated enclosure, as every order we manufacture is completely custom. However, we are happy to work to your specifications, including IP ratings. We do not provide any testing to IP ratings, therefore we cannot guarantee the rating itself. Contact us to discuss your needs.

Can my enclosure be waterproof?

Yes, it can. If you require a water-tight enclosure, we recommend a milled enclosure. Given that it is milled from solid stock, we are able to create a durable enclosure that is effective at protecting against the elements, and can even be immersed in water, provided you incorporate a custom gasket into the design.

Can I get a transparent enclosure?

At Protocase, we typically work with sheet metal; however we also work with materials such as acrylic. It is important to keep in mind that plastic materials cannot be bent.

We are able to install transparent plastic windows onto your custom sheet metal enclosure upon request. Read this customer spotlight that showcases an example of how an acrylic panel was used in a custom enclosure design.

Is Protocase compliant with international standards?

Yes, Protocase is ISO 9001 registered and AS9100 certified. We are also ITAR-compliant and registered with Canadian Controlled Goods.

Can you manufacture bezels?

Yes, we can. A bezel is essentially a cover or faceplate for an enclosure. We can build a sheet metal bezel, or a machined bezel, from your design.

Can you manufacture Raspberry Pi enclosures?

Yes, we can. Your Raspberry Pi enclosure can be manufactured using your CAD design, or you can use our design services to design a Raspberry Pi enclosure to suit your needs.

I need some brackets to hold down power supplies and fans. Can you supply these?

Yes, we commonly build internal components such as brackets, ground planes, internal partitions, etc., as an ordinary part of enclosure manufacturing. Please view our Materials, Components, and Finishes page page for complete information about the components we carry.

What are the dimensional tolerances of your enclosures?

The tolerance on variation of size and position of cutouts and profiles is +-0.005". For a full list of Fabrication Tolerances, please visit our Tolerance Resource here. If you have additional questions, please contact us.

How far do cutouts have to be from bends?

The minimum distance a cutout can be located from a bend is driven by the material type, thickness and tooling used to bend or bend radius required. You can refer to our Material Bend Radii and Minimum Bend Size Chart to determine the ideal value for your design. If you have additional questions, please contact us.

Where can I learn about your bend tolerances?

Check out our Fabrication Tolerances page, where we have listed all of our tolerances for your convenience.

What are the height restrictions for hat-shaped (offset) brackets?

• 0.50"+ material thickness for thicknesses .075" and up
• 0.29"+ material thickness for thicknesses up to.064"

Can you lathe parts?

Yes, we offer CNC Turning (Lathe), as well as CNC Machining with 5-Axis, 3-Axis and CNC Routers. View our CNC machining page to learn more about what we offer.

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What is a Hybrid Enclosure?

A Hybrid Enclosure is created using a combination of extruded sides, sheet metal top/bottom, and custom machined front and back plates. This creates a simple case that feels solid, durable and sophisticated, while the extruded sides have slots for mounting a circuit board. Learn more about Protocase's Hybrid Enclosures.

Do you manufacture bus bars?

Yes, we can build copper bus bars from your design in 2-3 days. Learn more about copper bus bars.

What is the internal height of your extruded aluminum enclosures?

Currently, we offer extruded aluminum enclosures in two different options: 1U, which is 1.72" (43.688mm) high and 2U, which is 3.47" (88.138mm) high. Learn more on our Extruded Aluminum page.

How did you get the numbers for your bend radii and minimum bend sizes?

Our minimum bend guidelines stem from a combination of in-house testing by our R&D and production teams, as well as manufacturer guidance on tooling. If you have specific bend requirements, contact us to discuss your needs.

Are you capable of fabricating offset bends?

Yes, we are able to fabricate offset bends, depending on your requirements. Contact your Protocase Account Manager to discuss your specific needs.

Can you make enclosures waterproof by seam welding the corners?

While we are not able to test for waterproofing in house, we are capable of creating enclosures that are water resistant and/or splash proof. Seam welding the enclosure's corners is a good option for water resistance; however, for a fully waterproofed enclosure, we recommend a CNC milled enclosure and employing an O-ring gasket. For more information, please view our blog post about designing enclosures that protect against water and debris.

by Ravi Jain, Bud Industries Inc.

Here are answers to commonly asked questions we hear from people selecting an electronic enclosure.

Which material is best for my application?

Electronic enclosures are made from plastic, die-cast aluminum, sheet metal, and fiberglass. Choosing the right material for your application depends on the environment in which the enclosure will be used. Engineering considerations include impact resistance, cooling and shielding, weight, corrosion resistance, and of course, cost.

Impact Resistance
Impact resistance, or more generally, material strength, is a primary consideration when selecting a material for your enclosure. Think about the end-use location. For example, will the enclosure be located high on a pole or on a machine where workers could bump it with a ladder? Think about the contents. Does it house critical factory controls or an optional tablet PC? What is the weight of the internal components?

• For high impact resistance, steel is a classic material favored in some industrial enclosure applications, such as large cabinets housing electrical components.
• Die-cast aluminum is another tough material. The casting process creates enclosures with thick walls and radiused corners that effectively distribute loads. It is more affordable than steel.
• Fiberglass enclosures gain high tensile strength by strengthening plastic with glass fibers.
• Fiberglass-reinforced polycarbonate plastic includes 10 percent glass fibers. It adds peace of mind in enclosure applications where moderate impact resistance is useful.

Cooling
Heat management is a constant in electronic design. Metal enclosures are effective at absorbing heat and dissipating it to the air outside the enclosure. Choices include steel, die-cast aluminum, sheet metal aluminum, and extruded aluminum.

Shielding
Metal enclosures naturally provide some level of EMI (electromagnetic interference) and RF (radio frequency) shielding. If an enclosure needs total EMI/RP protection, then the gasket needs to include a wire screen that covers the gap between the body and lid of the enclosure. (Bud’s IPS Series die-cast aluminum enclosure offers this type of shielded gasket.)

Weight

• Fiberglass is a good choice for large enclosures because it weighs far less than steel yet offers high impact resistance.
• Plastic is the lightest enclosure material, well suited for portable and handheld enclosures.
• Polycarbonate plastic enclosures weigh less than enclosures made of ABS plastic.
• Aluminum weighs less than steel, but is less rigid

Corrosion Resistance

• Unlike steel, plastic, fiberglass, and aluminum impart natural corrosion resistance to enclosures.
• Powder coating steel makes Increases its corrosion resistance
• For extreme corrosion resistance where high strength is needed, stainless steel is the safest choice.

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Cost
In one way or another, your enclosure choice typically involves a cost/benefit tradeoff. Because the cost of an enclosure represents a significant share of a bill of materials, specifiers should select the least costly material that will meet the requirements.

• ABS plastic has the lowest cost of all enclosure materials. Compared to polycarbonate plastic, it is heavier, less impact-resistant, and not UL rated.
• Polycarbonate plastic allows low-cost enclosures, especially when IP and NEMA ratings are required but at a higher than ABS
• Fiberglass enclosures are not inexpensive, but offer superior UV and weather resistance.
• Die cast enclosures are also low cost but share with plastics the very high tooling costs for modification of dimensions.
• There are various sheet metal enclosures which are often higher priced than plastic but do allow for more ready modifications of major dimensions.

Learn More
Selecting the ideal material is critical. This topic is covered in detail in our website article, “Choosing the Right Material for your Enclosure.” It includes descriptions and selection tips for:

• Steel Enclosures
• Aluminum Sheet Metal Enclosures
• Extruded Aluminum Enclosures
• Die-Cast Aluminum Enclosures
• Polycarbonate Plastic Enclosures
• ABS Plastic Enclosures
• Fiberglass Enclosures
• Fiberglass Reinforced Polycarbonate Enclosures

How do modifications affect UL ratings?

Electronic and electrical applications require openings in the enclosure for switches, indicators, displays, signal lines, and power wires. This creates something of a dilemma. You may source a UL approved enclosure, but cutting an opening in an enclosure will remove its UL rating. This means that you need to recertify your end design. Fortunately, UL is aware of the situation, and it has stated that by using an initially UL rated box with UL components (like switches, displays, and connectors) the UL approval process for your design will go much easier. See tips how to recertify on our enclosures FAQs page.

How to cool a cabinet

In normal operation, the biggest threat to the reliability of electronic equipment is heat, which can shorten the life of electrical components. Servers, computers, network switches, routers, and communications equipment all require a reasonable operating temperature. When these devices are located in a cabinet, various cooling strategies are used.

Internal components are typically mounted to a heat sink, a metal structure that conducts heat away from the component and releases the heat via radiation and convection. Basically, it transfers the heat to the air. The strategy for cooling a cabinet is to remove the hot air and replace it with cool air. Cabinets are well ventilated, allowing for natural airflow. When natural airflow is insufficient, designers add blowers and fans to flow air through the cabinet.

While fans are effective and low in both initial and operational cost, fans alone cannot remove enough heat in some critical applications. Cabinets with air conditioning and liquid cooling systems provide cooling in these applications, although at high cost.

Engineers specifying a cabinet rack must understand where to locate cooling features inside the cabinet. The considerations include:

• Chimney effect
• Fans versus blowers
• Backpressure
• Ventilation
• Dust
• Locations in the cabinet
• Air conditioning
• Airflow calculations

All of these considerations are discussed in our white paper, The Basics of Enclosure Cooling.

How to prevent condensation in an enclosure?

Condensation occurs when humidity in the air collects on a cool surface, such as water drops collecting on the outside of a cold glass of lemonade on a hot day. While condensation is not a problem for lemonade, it poses a serious threat to electronic components. Moisture can cause corrosion leading to premature failure. It can even create damaging electrical shorts.

Condensation is a concern in humid locations that are subject to swings in temperature. It is not typical in indoor locations, and it is not even common to all outdoor locations. Nevertheless, a designer may not know all the locations settings which an end product will be used, and so schemes to prevent condensation should be employed.

Different strategies are used to mitigate condensation. Each has advantages and disadvantages.

Heating the cabinet.
Sometimes designers add heating elements to the bottom of enclosures (large cabinets, not small box enclosures). The heating elements assure the interior components never get cold enough for condensation to form (above the dew point). Unfortunately, heat can shorten the life of electrical components and increase nuisance tripping of overcurrent protection devices. In most electronics applications, designers try to remove heat.

Air conditioning the cabinet.
Air condition both cools the air removes moisture from cabinets. It prevents condensation and maximizes component life. On the other hand, it adds a great deal of expense and complexity, which is not practical in most applications. Both air conditioning and heating systems require thermostat controls, use a lot of energy, and will eventually require maintenance.

Sealing the enclosure.
A tight seal, available in enclosures rated IP65/NEMA 4 and higher, will prevent moisture from entering the enclosure. This is the usual strategy for box enclosures and small cabinets. The downside is that warm air cannot escape the enclosure. Also, atmospheric pressure changes caused by changing weather can create a pressure difference large enough to cause gaskets to fail over time.

Using IP rated vents.
To allow air pressure inside an enclosure to equalize with the outside air pressure, a designer may install a vent. The vent also allows heat to escape from the enclosure. Recently, IP rated vents have become available. These use special breathable fabric that permits airflow but blocks moisture that could otherwise cause condensation.

Using a vortex cooler.
If compressed air service is available on-site, then designers can employ a technique to use that air for cooling. The vortex cooler spins the air into a vortex. The vortex separates the cool air, which can be directed through the cabinet. These systems are loud and consume a lot of air. Just because compressed air is already there, cooling isn’t free, as the compressor costs money to run. One advantage of vortex cooling is that the positive air pressure helps keep out dust.

What do enclosure flammability ratings mean?

Any plastic has its origin in petrochemicals and is ultimately flammable. Fortunately, flame retardant additives make plastic resistant to fire, a feature that is important in many enclosure applications, especially in manufacturing and hazardous locations.

The UL 94 standard defines the various levels of flame resistance. Flammability ratings let the specifier know how the material in a plastic enclosure will behave if exposed to fire. Will it protect against fire, or will it contribute to it? The ratings are how you know.

The main two things measured by the standard are how fire spreads on the wall of the enclosure and if drips of melting plastic are in flame. Although the standard is for enclosures specifically, the tests are done on a sample of the material.

Our blog post, “Flammability 101 for Plastic Electronic Enclosures,” describes each UL enclosure flammability rating and associated test:

• HB
• V-2
• V-1
• V-0
• 5VB
• 5VA

The tests are performed on horizontal samples or vertical samples. The tests specify burning time before self-extinguishing. Read our blog post for how to specify an enclosure flammability rating.

Now that we have answered your common questions about enclosures, find the enclosures that you need by searching by size, type, and other characteristics.

Contact us to discuss your requirements of Custom Enclosure Solutions. Our experienced sales team can help you identify the options that best suit your needs.