Whether you're replacing a sensor, an enclosure, a motor or a push-button, its environmental rating decides whether it survives. Two systems are used: IP (international) and NEMA (North American). Here's how to read both.
The IP code: two digits
IP stands for Ingress Protection. The first digit is protection against solids, the second against liquids — higher is more protected:
- First digit (solids): 5 = dust-protected, 6 = fully dust-tight.
- Second digit (liquids): 4 = splashing, 5 = water jets, 6 = powerful jets, 7 = temporary immersion, 8 = continuous immersion.
- So IP65 = dust-tight + water jets; IP67 = dust-tight + immersion to 1 m; IP54 = dust-protected + splash.
NEMA enclosure ratings
- NEMA 1: indoor, general purpose (dust, incidental contact).
- NEMA 3R: outdoor, rain and sleet.
- NEMA 4: indoor/outdoor, watertight and washdown (hose-down).
- NEMA 4X: as 4, plus corrosion resistance (stainless / food & chemical).
- NEMA 12: industrial, dust, dripping liquids and oil.
- NEMA 7/9: hazardous (explosive) atmospheres.
Rough NEMA-to-IP cross-reference
They don't map exactly (NEMA also tests corrosion, icing and gaskets), but as a guide: NEMA 1 ≈ IP20, NEMA 3R ≈ IP24, NEMA 4/4X ≈ IP66, NEMA 12 ≈ IP54/IP65. A NEMA rating can be used to claim an IP equivalent, but not always the reverse.
Match or exceed the original
When replacing a part, meet or exceed the original rating — a lower rating in a washdown or dusty area will fail early. If you're unsure what a part needs, tell us where it's installed and we'll spec and quote one that holds up.