The national standard Protection Rating of Enclosures for Low-Voltage Electrical Appliances sets rules for the classification, grading, marking, definition, test methods, and conformity checks of the protection ratings for low-voltage electrical appliance shells (we call these “electrical appliances” for short).
1.What a protection rating code includes
It has the letter “IP” followed by two numbers and optional extra letters. The first number (and any extra letter after it) shows the first type of protection, and the second number shows the second type.
2.Protection from the first number (and extra letter)
This protects people and internal parts of the cabinet. There are 9 levels, as shown in Table 2.2.5
| First Number and Extra Letter After It | Code | Protection Level | Simple Explanation |
|---|---|---|---|
| 0 | IP0X | No protection | No special protection |
| 1 | IP1X | Stops solid objects over 50mm in diameter | Stops large parts of the body (like fingers) from accidentally touching live or moving parts inside; stops solid objects over 50mm in diameter from getting in |
| 2L | IP2LX | Stops solid objects over 12.5mm in diameter | Stops solid objects over 12.5mm in diameter from getting in; stops fingers or similar tools (up to 80mm long) from touching live or moving parts inside |
| 3 | IP3X | Stops solid objects over 2.5mm in diameter | Stops tools, wires, etc., over 2.5mm in diameter (or thickness) from getting in |
| 3L | IP3LX | Stops solid objects over 12.5mm and a 2.5mm probe | Stops solid objects over 12.5mm from getting in; stops 2.5mm-diameter probes (up to 100mm long) from touching live or moving parts (like wires) inside |
| 4 | IP4X | Stops solid objects over 1mm in diameter | Stops solid objects (like wires) over 1mm in diameter (or thickness) from getting in |
| 4L | IP4LX | Stops solid objects over 12.5mm and a 1mm probe | Stops solid objects over 12.5mm from getting in; stops 1mm-diameter probes (up to 100mm long) from touching live or moving parts (like wires) inside |
| 5 | IP5X | Dust protection | Some dust may get in, but not enough to affect the electrical appliance’s work |
| 6 | IP6X | Dust-tight | No dust gets in |
Notes:
- The “Simple Explanation” here is just a summary, not an official rule for protection.
- The “Explanation” tells us what objects the protection level can “stop” from getting in.
- For electrical appliances with the first number 1-4 (including 2L, 3L, 4L), the solid objects they stop include both regular and irregular shapes. All three of their perpendicular dimensions are larger than the values in the “Explanation”.
- Cabinets with drain holes or vents must meet their “IP” rating requirements. During tests, holes meant to be open or closed at the installation site must stay that way.
In Table 2.2.5, the protection levels (from lowest to highest) are: 0, 1, 2L, 3L, 4L, 3, 4, 5, 6. If a cabinet meets a level, it also meets all lower levels. We don’t need to test lower levels unless we’re unsure.
3.Protection from the second number
This stops water from getting in and causing harm. There are 9 levels, as shown in Table 2.2.6.
| Second Number | Code | Protection Level | Simple Explanation |
|---|---|---|---|
| 0 | IPX0 | No protection | No special protection |
| 1 | IPX1 | Stops drips | Vertical drips won’t cause harm |
| 2 | IPX2 | Stops drips | If the appliance tilts up to 15° from normal, vertical drips won’t cause harm |
| 3 | IPX3 | Stops sprays | Sprays within 60° of the horizontal won’t cause harm |
| 4 | IPX4 | Stops splashes | Splashes from any direction won’t cause harm |
| 5 | IPX5 | Stops jets | Water sprayed from a nozzle (any direction) won’t cause harm |
| 6 | IPX6 | Stops waves | Strong waves or heavy sprays won’t let in enough water to cause harm |
| 7 | IPX7 | Stops harm from being immersed | If the appliance is in water at a set pressure for a set time, not enough water gets in to cause harm |
| 8 | IPX8 | Stops harm from diving | If the appliance dives for a long time at a set pressure, no water gets in |
Notes:
- The “Simple Explanation” here is just a summary, not an official rule for protection.
- The “Explanation” tells us how the second number protects against water.
If a cabinet meets a level, it also meets all lower levels. We don’t need to test lower levels unless we’re unsure.
4.Using extra letters
- W: Put after “IP” – means the cabinet has extra protection and works in specific climates.
- N: Put after the second number – means the cabinet has extra protection and works in specific dusty places (like sawmills or quarries).
- L: Put after the first number 2, 3, or 4 – means the cabinet has extra protection, stopping solid objects or probes from touching live or moving parts inside under set conditions.
Manufacturers and users must agree on the specific climates, dusty environments, objects, probes, and extra protection measures.
5.Omitted numbers
If we only need one number to show the protection level, we use “X” for the omitted one. For example, IPIX, IP2LX, IP4X, IP5X (as in Tables 2.2.5 and 2.2.6).
6.Complete protection levels
If we use two numbers (or add extra letters) to show a product’s full protection level, we must test it as required in Tables 2.2.5 and 2.2.6. If there are no extra letters W, N, or L, the protection level works in all normal conditions.
7.Examples of codes
- IP65: Stops dust from getting in and stops water jets.
- IP4L4: Stops solid objects over 12.5mm from getting in, stops 1mm-diameter probes (up to 100mm long) from touching live parts, and stops splashes.
- IPW33: Works in specific climates, stops solid objects over 2.5mm from getting in, and stops sprays.
