Certifications can be made not only with UL standards, but also with ASME, IEEE, ISA, NEMA standards,
NFPA etc. After certifying a product, the NRTL authorizes the manufacturer to affix a registered trademark to it. When a product bears a certification mark, it means that the NRTL has tested and certified the product and that it complies with the requirements of one or more standards.
IP coding
The coding, established by EN60529 implemented by the Italian Electrotechnical Committee standard CEI70-1, is as follows:
IPXXab
The fixed term IP is followed by two digits and two optional letters. The figures indicate compliance with the conditions summarized in the table below. When there are no protection values concerning one of the criteria, the digit is replaced by the letter X. The first digit indicates the level of protection that the enclosure provides against access of hazardous parts[2] (e.g., electrical conductors or moving parts) and entry of solid foreign objects.
| Grade | Definition | Protection |
|---|---|---|
| IP0X | Not protected from contact and entry of objects | / |
| IP1X | Protected against solid bodies larger than 50 mm | Any large surface of the body, such as the back of the hand, but no protection against contact ntentional with a body part (50 mm). Protected against access with the back of the hand. |
| IP2X | Protected against solid bodies larger than 12 mm | Protected against access with a finger or similar objects. |
| IP3X | Protected against solid bodies larger than 2.5 mm | Protected against access with a tool, large cables, etc. |
| IP4X | Protected against solid bodies larger than 1 mm | Protected against access with a cable, thin screws, small screwdriver, etc. |
| IP5X | Protected against dust | Protected against dust ingress. The entry of dust is not completely prevented, but must not enter in a sufficient amount to interfere with the satisfactory operation of the equipment. |
| IP6X | Dust-tight | Fully protected against the entry of dust, sand and generally any Small-sized solid body. No dust penetration; complete protection from contact (dust-tight). Vacuum must be applied. Test duration up to 8 hours depending on airflow. |
Protection against liquid access.
The second digit indicates the level of protection the enclosure provides against liquid access.
| Grade | Definition | Protection |
|---|---|---|
| IPX0 | Unprotected | / |
| IPX1 | Protected from vertical fall of water drops | Duration of the test: 10 minutes. Water equivalent to 1 mm of rain per minute |
| IPX2 | Protected from falling water drops with maximum inclination of 15° | Test duration: 2.5 minutes for each tilt direction (10 minutes total). Water equivalent to 3 mm of rain per minute |
| IPX3 | Protected from the rain |
With a spray nozzle.
Test duration: 1 minute per square meter for at least 5 minutes[
3]. Water volume: 10 liters per minute.
Pressure: 50-150 kPa. With an oscillating tube. Duration of the test: 10 minutes. Water volume: 0.07 l/min per hole. |
| IPX4 | Protected from splashing | With an oscillating tube. Test duration: 10 minutes or spray nozzle (same as test with spray nozzle for IPX3 but with shield removed) |
| IPX4K | Protection against splashing water under pressure, worth for road vehicles only | / |
| IPX5 | Protected from water jets | Test duration: 1 minute per square meter for at least 15 minutes. Water volume: 12.5 liters per minute. Pressure: 30 kPa at the distance of 3 m |
| IPX6 | Protected by waves | Test duration: 1 minute per square meter for at least 3 minutes. Water volume: 100 liters per minute. Pressure: 100 kPa at the distance of 3 m |
| IPX6k | Protection against strong high-pressure water jets (flooding), applies to road vehicles only | Test duration: at least 3 minutes. Water volume: 75 liters per minute. Pressure: 1000 kPa at the distance of 3 m |
| IPX7 | Protected by temporary immersion | Immersion to a depth of 1 m for up to 30 minutes, must not have water penetration Test duration: 30 minutes-ref IEC 60529, Table 8. Tested by holding the lowest point of the casing at 1000 mm below the surface. of water, or the highest point at 150 mm below the surface, depending on Of which is the deepest. |
| IPX8 | Protected by permanent immersion | Test conditions in accordance with the manufacturer, but more stringent than IPX7. Duration greater than or equal to 30 min (typically 24 hours). Depth greater than 1 m (typically over 3 m) |
| IPX9 | Protected against high pressure and high temperature water jets | Water pressures between 80 bar and 100 bar in all directions at high temperature (75...85 °C). Test duration for enclosures 250 mm: 1 min per m2 (minimum 3 min). |
| IPX9k | Protection against water in the case of steam / and pressure cleaning, applies to road vehicles only | Test duration: 30 seconds in each of the 4 angles (0° - 30° - 60° - 90°) 2 minutes total. Water volume: 14-16 liters per minute. Pressure: 8-10 MPa (80-100 bar) at the distance of 0.10-0.15 m. Water temperature: 80 °C. |
Optional letters
Optional additional letter, protection against human access
| Grade | Protection |
|---|---|
| a | UnprotectedProtected against access with the back of the hand |
| b | Protected against one-finger access |
| c | Protected against access with a tool |
| d | Protected against access with a wire |
Optional additional letter, material protection
| Grade | Effects |
|---|---|
| h | High-voltage equipment |
| m | Proven against harmful effects due to water ingress with equipment in motion |
| s | Proven against harmful effects due to water ingress with equipment not running |
| w | Suitable for use in specified weather conditions |
IP69K and IP69
| NEMA 250 Coding | IP Correspondence |
|---|---|
| 1 | IP10 |
| 2 | IP11 |
| 3R | IP14 |
| 3 | IP54 |
| 3S | IP54 |
| 4 | IP66 |
| 4X | IP66 |
| 5 | IP52 |
| 6 | IP67 |
| 6P | IP67 |
| 12 | IP52 |
| 12K | IP52 |
| 13 | IP54 |