A NEMA 3R enclosure, also called a Type 3R enclosure, is designed for indoor or outdoor use and protects the equipment inside against falling rain, sleet and snow, and is undamaged by external ice formation. It does not require protection against windblown dust, hose-directed water or submersion. This page explains what a NEMA 3R enclosure covers, how it compares with other NEMA types, and what to check before you choose one.
What Does NEMA 3R Mean?
NEMA Type 3R comes from NEMA 250, the standard that defines enclosure "Types" in the United States. The "R" stands for rainproof. A Type 3R enclosure also gives a degree of protection against falling dirt and against accidental contact with the equipment inside. For the bigger picture of how these ratings fit together, see NEMA enclosure ratings.
What Does a Type 3R Enclosure Protect Against?
|
Protects against |
Does not protect against |
|
Falling rain, sleet and snow |
Windblown dust |
|
Falling dirt |
Hose-directed water or heavy washdown |
|
Accidental contact with enclosed equipment |
Submersion |
|
Damage from external ice formation |
Corrosion (unless it is a 3RX type) |
Many NEMA 3R enclosures include drain or weep holes so any moisture that gets in can escape. Check the manufacturer's specification for the model you are considering.
Is NEMA 3R Waterproof?
No. NEMA 3R is rainproof, not waterproof. It is designed for rain, sleet and snow falling on the enclosure, not for hose-down cleaning or immersion. If water jets or flooding are possible, you need a higher rating.
NEMA 3R vs. NEMA 3, 3RX, 4 and 4X
|
Type |
Rain, sleet, snow |
External ice |
Windblown dust |
Hose-directed water |
Corrosion resistance |
|
3R |
Yes |
Yes |
No |
No |
No |
|
3RX |
Yes |
Yes |
No |
No |
Yes |
|
3 |
Yes |
Yes |
Yes |
No |
No |
|
4 |
Yes |
Yes |
Yes |
Yes |
No |
|
4X |
Yes |
Yes |
Yes |
Yes |
Yes |
In short, 3R does not cover dust or hose-down water, Type 3 adds windblown dust protection, Type 4 adds hose-directed water, and the "X" types add corrosion resistance. For a closer look at the two types people most often compare, see NEMA 4 vs. NEMA 4X.
Is There an IP Equivalent to NEMA 3R?
There is no exact IP equivalent to NEMA 3R. NEMA Types include tests, such as external ice formation and corrosion resistance, that IP codes do not cover, so one system cannot be converted into the other. NEMA's own standard offers only a rough, one-way comparison from NEMA Types to IP codes, and it is not a substitute for testing. If you want to understand the IP side, our guide to IP water resistance ratings explains what each water level means.
Where Are NEMA 3R Enclosures Used?
NEMA 3R enclosures are common wherever equipment sits outdoors without exposure to hose-down water or heavy dust, such as outdoor electrical panels, meter and disconnect enclosures, and control or communication equipment. Suitability always depends on the actual site conditions and any local code or inspector requirements.
Do You Need More Than NEMA 3R?
Consider a higher rating if the enclosure will face windblown dust, regular washdown, corrosive or coastal air, or any chance of submersion. Each of these is outside what 3R is designed to handle.
Saipwell Metal Enclosures with UL 508A and IP66
Saipwell metal enclosures are built for demanding electrical installations. Selected SPB and SPT models are covered by UL 508A certification for industrial control panel enclosures (tested as empty enclosures), and our metal enclosures are IP66-rated, with dust-tight construction and protection against powerful water jets. Check each listing for the exact certification and rating of your model before you buy.
