Which Electrical Enclosure Should I Use?

While the electrical and electronic devices required in the assembly of a control panel are the focus of your design efforts, underestimating or delaying the selection of an appropriate enclosure might cause significant issues which can be avoided with just a bit of forethought. Consider these key factors in advance and save yourself headaches.

Which Electrical Enclosure Should I Use?

A quick Google search for “electrical enclosures” returns 58 million results so it is not surprising that some specifiers may feel a bit overwhelmed at the task. For most applications, there is a perfectly acceptable solution readily available – in fact Hammond Manufacturing alone has over 6,000 standard electrical enclosures and accessories. Reaching out to an enclosure supplier for support when needed is ideal, but you will need to know some critical information to decide what’s appropriate.

There are many factors that can affect the selection of an enclosure for a particular application. We will focus on seven common considerations for Electrical Enclosures:

1. Protection Rating

2. Certifications and Approvals

3. Size

4. Access Needs

5. Cost

6. Temperature Environment

7. Corrosion Resistance.

Protection Rating

An enclosure’s protection rating indicates the degree of protection that the enclosure provides for the equipment that is inside. Enclosures are rated according to their ability to prevent various levels of dirt and liquids from entering. These protection levels are commonly referred to as “Type” or “NEMA” (National Electrical Manufacturers Association) ratings.

The table shown here outlines the “Type”/”NEMA” ratings and protection levels for Hammond Enclosures.

This table outlines the “Type”/”NEMA” ratings and protection levels for Hammond Enclosures.

Certifications and Approvals

Standards organizations create rating measurements for the performance of different products. Electrical enclosures categories are defined by organizations like NEMA, CSA, UL, and IEC to identify an enclosure’s ability to provide protection from dust, dripping water, hose directed water, and more.

While these standards are all intended to guide the user to make the right choice of product, there are some important differences between them.

In North America, NEMA, UL, and CSA are the most commonly recognized standards organizations. They are almost identical in their rating and testing of enclosures.

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UL and CSA require that enclosures be tested in an approved lab in order to prove their performance. They regularly inspect manufacturers to ensure they use the approved materials and construct to previously tested product designs. In turn, they provide “certification labels” to be permanently attached inside the enclosures.

While NEMA ratings are a common reference, distinct from UL/CSA, that organization does not provide testing services, they leave compliance and testing to the discretion of the manufacturer, and they do not provide “certification labels” for enclosures.

In Europe, IEC ratings are the most commonly recognized standards for enclosures. IEC ratings are similar to NEMA, but the pass or fail requirements are different. IEC primarily focuses on ingress protection and does not include distinct ratings for enclosures in conditions of corrosion, rust, oil, ice, or explosive (hazardous) environments.

IEC does not provide testing, so testing and compliance is left up to the manufacturer. In Europe, TUV and VDE are two popular, testing agencies that manufacturers sometimes use to validate protection levels.

Size

Kind of basic, but consider the minimum dimensions of the enclosure needed to house all of the installed components – e.g. how deep is the deepest component? Then, confirm if there are physical size limitations in the area where the enclosure is to be installed – is the space available wide open, short and wide, tall and thin, etc.

Hammond has over 600 sizes of standard enclosures available from inventory to meet almost every size of application. While sometimes necessary, specifiers that request a custom size will likely limit their supplier options, increase costs, and lengthen lead times.