IP44. IP67. NEMA 3R. NEMA 4X.

Environmental ratings show up on everything from temporary power equipment to industrial connectors, but choosing between them is not always straightforward.

A connector designed for a construction site may not be the right choice for a washdown environment. Likewise, a device rated for splashing water may not provide the protection needed for repeated outdoor exposure.

That's why one of the questions we hear most often at Walther Electric is:

What’s the difference?

Why Environmental Ratings Exist

Most electrical equipment spends its life needing to function while dealing with weather, dust, moisture, vibration, or some combination of environmental hazards.

Consider a few environments where electrical equipment is expected to perform:

• A temporary power distribution system sitting outside during a week of rain
• A marine installation exposed to moisture and salt air
• A manufacturing facility generating dust and airborne debris
• A food processing line that undergoes routine washdowns

Each presents different risks. Environmental ratings provide engineers and contractors with a standardized way to evaluate how well equipment can withstand specific operating conditions, making it easier to identify products designed for the demands of a particular environment.

Understanding IP Ratings

IP stands for “Ingress Protection.” The two numbers that follow indicate how well a device is protected against solid objects and moisture.

For industrial applications at Walther Electric, the most common ratings are IP44 and IP67.

IP44: Protection from Splashing Water

IP44 devices are protected against solid objects larger than 1mm and water splashing from any direction.

For many temporary power and outdoor applications, that level of protection is exactly what is needed. Common examples include controlled indoor facilities, events, temporary installations, and general outdoor use where exposure to rain is expected but immersion is not.

That is why IP44 remains one of the most common ratings found on IEC 60309 Pin & Sleeve devices.

IP67: Dust Tight and Watertight

IP67 provides significantly greater protection.

The first digit, “6,” indicates complete protection against dust ingress, while the second digit, “7,” indicates protection against temporary immersion in water under specified conditions.

This makes IP67 a common choice for marine environments, utility applications, washdown areas, and outdoor deployments where dust, moisture, or harsher environmental exposure are concerns.

Many of Walther Electric’s IEC 60309 Pin & Sleeve devices achieve IP67 protection through design features such as external cable glands and ring-shaped bayonet locking systems that create a seal between the plug and receptacle.

Understanding NEMA Ratings

IP ratings focus on protection against dust and water. NEMA ratings expand the focus to the enclosure's overall performance in the environment.

For North American users, NEMA ratings are commonly used to describe enclosures designed for outdoor exposure, corrosion resistance, or washdown applications.

NEMA 3R: Built for Outdoor Weather

If you’ve ever seen a power distribution unit sitting outdoors through rain, sleet, or changing weather conditions, you’ve seen an application where NEMA 3R matters.

NEMA 3R's ability to withstand outdoor environmental conditions makes it a popular choice for power distribution applications, including many of Walther Electric's Portable Power Distribution Units (PDUs). 

NEMA 4X: Protection for Demanding Environments

Some environments are harder on electrical equipment than weather alone.

Food processing facilities, marine environments, wastewater facilities, and industrial washdown areas often expose equipment to moisture, cleaning chemicals, and corrosive conditions. That is where NEMA 4X comes into play.

One example is Walther Electric’s Mechanical Interlock devices. These units are gasketed and rated as watertight NEMA 4X enclosures while also providing important safety functions by preventing plugs from being inserted or removed under load.

When paired with compatible Walther Electric IP67 plugs, the entire connection system can sustain NEMA 4X protection.

Which Rating Do You Actually Need?

The best rating is not necessarily the highest one. It is the one that matches the environment.

A temporary outdoor event may only require IP44 or NEMA 3R protection. A marine installation or washdown area may call for IP67 or NEMA 4X equipment.

A practical rule of thumb: 

If the concern is…	Common Rating
Splashing water	IP44
Outdoor weather	NEMA 3R
Dust and temporary immersion	IP67
Washdowns and corrosion	NEMA 4X

The goal is not simply to choose the most protective option available. It is to choose equipment that matches the environment without adding unnecessary cost or complexity.

Matching Equipment to the Environment

A connector on a construction site does not face the same challenges as one installed at a marina or inside a food processing facility.

Environmental ratings were developed to create a standard language around those differences.

Whether you are selecting IEC 60309 Pin & Sleeve devices, Portable Power Distribution Units, Mechanical Interlocks, or another electrical product, the same principle applies:

Match the rating to the environment.

An IP67 connector is not automatically a better choice than an IP44 connector, just as a NEMA 4X enclosure is not always necessary where a NEMA 3R enclosure will do the job. The right rating is the one that fits the application.

View Catalogs: Electrical Products for Demanding Environments
Shop Products: Find the Right Rating for Your Application