NEMA 4 vs. NEMA 12 Electronics Enclosure

The NEMA 4 and NEMA12 are two most commonly confused electronics enclosure ratings. Several customers easily assume that they need a NEMA 4 for their engineering project, simply because it is one of the highest levels of protection for weatherproof cabinet. However, if the needs are not well identified, the user can spend too much on buying a NEMA 4 – and opt for a NEMA 12 instead.

When you want to choose electrical enclosures, there are 2 factors you should consider.
First, which environment will you use it? Is it indoor or outdoor?
Second, what level of protection in the above environment that is required?

Once the customer recognizes their need to use electronics enclosure for their engineering project, the user should take into consideration the type of protection they need.

The National Electrical Manufacturer Association (NEMA) has successfully identified and established different enclosure ratings to help the company and the customer alike. NEMA has defined a structure to different NEMA definitions on protection to 13 levels, to establish us identify which type of enclosure will suitable to protect the enclosure and equipment inside. The result of selecting the wrong type of enclosure can lead to inferior protection for inside equipment in a particular environment.

If in case the customer made a wrong decision on the electronics enclosure they purchased, it is both wastes of money and time. They should have the right knowledge in mind before making a purchase decision. The wrong enclosure could also bring damage to their equipment because of incompatibility in terms of use, type of protection needed, and where it will be used.

With this in mind, there are two most commonly confused electronics enclosure ratings – the NEMA 4 and NEMA 12. Several customers easily assume that they need a NEMA 4 for their engineering project, simply because it has one of the highest levels of protection. However, if the needs are not well identified, the user can spend too much on buying a NEMA 4 – and opt for a NEMA 12 instead.

There’s a simple way on how to identify if a user should purchase a NEMA 4 or NEMA 12.

If an engineer or company plans on buying an enclosure to protect and support systems & technology situated in an outdoor environment, where potential water ingress is expected or there is potential direct exposure to sunlight, the user should use NEMA 4.

If however, the user is planning to protect equipment being used inside a covered warehouse structure where there is potential object ingress from floating dust in the environment, the customer should opt for a NEMA 12. Given that the environment has minimum to no water present or even moisture.

Typically utilized to protect a standard IT networking series of connection, automated electronics, or equipment used for transportation signal controls, phone and cable network distribution, and security or communications equipment.

Used to protect equipment in automation control or electronic system drives, this also includes the equipment used in packaging, material handling, and non-corrosive process control in manufacturing plants.

If it will be used under outdoor environment, expect windblown dust and rain, splashing water, and hose-directed water (Heavy spray down water). We would recommend you to use a NEMA 4 enclosure. NEMA 250 rating, the minimum requirement to pass NEMA 4 standard is water from fire hose 65 gallons (246L)/min. -5 min and no water get inside the enclosure.

If it will be used under an indoor environment, only expect windblown dust, hot temperature, a little bit of splashing water expected. We would recommend you to use a NEMA 12 enclosure. NEMA 250 rating, the minimum requirement to pass NEMA 12 standard is water 30 min. Drip Test30 psi (200kPa) Spray Test and no water inside the enclosure.

However, if you are not sure which NEMA rating should you use please check it out Nemaco NEMA comparison chart

Nemaco offers both NEMA 4 and NEMA 12, in different materials, Aluminum, Carbon steel, Stainless steel with a choice of powder coated colors white, light gray (ASA70), dark gray (ASA 61) and black.