1. How to Interpret IP Ratings
How to interpret IP ratings.
Based on International Electrotechnical Commission (IEC) practices, the rating system is understood as follows: **Definition**—IP Rating (Ingress Protection Rating; defined by the IEC 60529 standard; used to evaluate the protection provided by equipment enclosures against the intrusion of solid foreign objects—such as dust—and liquids—such as water; also known as the IP code for enclosure protection); **Composition**—”IP” followed by two digits (the first digit governs protection against solid particles/debris, the second against water intrusion; generally, higher numbers indicate stronger protection); **Dust Protection**—First digit ranges from 0 to 6 (0: no protection; 1: protects against objects >50mm, e.g., hands; 2: protects against objects >12mm, e.g., fingers; 3: protects against objects >2.5mm, e.g., tools/wires; 4: protects against objects >1.0mm, e.g., fine debris; 5: dust-protected—limited ingress allowed, but no harmful effects on operation; 6: dust-tight—complete protection, no dust ingress); **Water Protection**—Second digit ranges from 0 to 8 (0: no protection; 1: protects against vertically dripping water; 2: protects against dripping water when tilted up to 15 degrees; 3: protects against spraying water; 4: protects against splashing water; 5: protects against water jets—no effect from jets in any direction; 6: protects against powerful water jets—high pressure/high flow; 7: protects against short-term immersion—1 meter depth for 30 minutes; 8: protects against continuous submersion—depth and duration specified by the manufacturer, no unified standard); **Standards**—The Chinese national standard GB 4208-2008 corresponds to IEC 60529:2001 (test conditions: 15–35°C, 25–75% relative humidity, 86–106 kPa atmospheric pressure)—Understanding IP ratings involves four aspects: the IEC 60529 standard, the first digit (dust protection 0–6), the second digit (water protection 0–8), and the domestic GB 4208 equivalent;
interpreting these two digits reveals the rating.
II. Selection Based on Environment
How to select based on the environment.
Based on practical experience in selecting protection ratings, choices are made according to the environment: **Indoor**—IP23 suffices for standard indoor equipment (protection against solid objects >12mm and dripping water); IP30 or IP40 for power distribution cabinets in dry, dust-free indoor settings (protection against fingers/small debris, no water protection); IP44 or IP54 for humid, dusty workshops (dust and splash protection). **Outdoor**—At least IP54 for exposed outdoor environments (dust and side-spray protection); IP54 or higher is mandatory for open-air settings; IP65 for areas prone to heavy rain or water accumulation (incorporating rain eaves and elevated bases); IP66/67 for harsh seaside environments. **Harsh Conditions**—IP65 for harsh environments (outdoors or exposed to heavy rain, strong winds, or seawater); IP67 for even harsher conditions (high/low temperatures, high pressure, corrosion, or special environments); IP68 for long-term submersion or deep-water operation. **Underwater**—IP68 for submersible equipment requires specifying the water depth (e.g., IP68 at 10 meters; avoid vague labeling). **Scenarios**—IP67 for underground garages prone to water accumulation; IP68 for long-term submersion; IP65 for outdoor areas under eaves; IP66 for fully exposed outdoor areas. Summary of the four-tier approach: Indoor (IP20/40), Workshop (IP54), Open-air (IP65+), Underwater (IP67/68);
select the specific rating based on actual operating conditions.
III. Selection Based on Components
How to select based on components.
Based on industrial selection practices, components are selected as follows: Motors—IP23 for open, indoor ventilated environments (e.g., fan motors); IP54 for standard industrial workshops (dust-proof and splash-proof, suitable for water pumps and gear reducers); IP55 for outdoor, mining, or dusty workshops (capable of withstanding high-pressure washing); IP65 for harsh conditions involving moisture and dust (e.g., car wash equipment); and IP67 or IP68 for submersible pumps. Servo motors—IP54 for standard workshops (limited dust protection and splash resistance for general environments); IP65 or higher for dusty workshops (to prevent dust ingress affecting heat dissipation and insulation); oil-mist environments require oil-mist and water resistance (paying attention to the oil resistance of connectors and seals); and IP67 or higher for wash-down environments (capable of short-term immersion or high-pressure washing, with connectors requiring matching protection levels). The three-step selection method involves: first assessing the environment, then selecting the protection rating, and finally verifying compatibility with the complete machine assembly. Power distribution cabinets—IP20 for dry indoor areas where personnel might make contact (finger-safe but not waterproof); IP30/IP40 for general industrial workshops (protection against small debris but not waterproof); IP54 for indoor or semi-outdoor areas with dust and moisture (dust-proof and splash-proof); IP65 for standard outdoor environments (fully dust-proof and jet-proof); IP66 for outdoor scenarios with heavy rain or wash-downs (fully dust-proof and resistant to powerful water jets); and IP67/IP68 for harsh environments involving moisture or submersion (dust-proof and immersion-resistant). Actuators—IP65 for dry indoor locations; IP67 for damp outdoor locations (mandatory for sewage plants, chemical facilities, areas with standing water, and lithium battery manufacturing); and IP68 for underwater use (generally unnecessary for standard projects). Summary of component selection: select motors based on operating conditions, servo motors based on the workshop environment, power distribution cabinets based on the specific scenario, and actuators based on moisture levels (dry vs. wet);
match the component to the specific requirement.
IV. Common Pitfalls to Avoid
What to look out for to avoid common pitfalls.
Based on practical selection experience, here is how to view common misconceptions: IP67 is not necessarily superior to IP66—IP67 tests for static immersion, whereas IP66 tests for high-pressure water jets; the conditions differ (coastal typhoon zones require IP66 resistance to high-pressure water impact rather than IP67 immersion resistance; IP66 offers resistance to both salt spray and powerful water jets). “X” indicates an unspecified rating—an “X” means the specific protection aspect is not declared, not that it is rated “0” (e.g., IP5X does not mean dust-tight; only IP6X is dust-tight; the first digit ranges from 0 to 6, and the second from 0 to 8). Dust and water protection—the first digit represents the dust protection level (0–6) and the second the water protection level (0–8); while higher numbers generally indicate stronger protection, the core principle of IP ratings is not simply “higher is better,” but rather selecting the right rating for actual operating conditions. Heat dissipation—high protection ratings imply tight sealing, which often compromises heat dissipation performance (special attention to thermal design is required for IP54 and above). Scope limitations—IP ratings do not cover resistance to impact, corrosion, or UV exposure (these are governed by other standards). The system’s weakest link—IP is just one component of the protection system (actual leaks often stem from misaligned seals, incorrect compression, inconsistent screw torque, or structural modifications). Summary of four key considerations: IP67 isn’t always better than IP66 (consider the scenario); “X” means unspecified, not “0”; higher numbers can mean poorer heat dissipation;
and the system’s weakest link determines actual performance—keep these four points in mind to avoid selection pitfalls.
V. Testing and Labeling
What to look for regarding testing and labeling.
Based on practical testing experience, here is what to look for: **Test Methods**—Laboratories verify protection performance using standardized methods such as drip test apparatus and oscillating tube spray equipment (recommended conditions: 15–35°C, 25–75% relative humidity, 86–106 kPa atmospheric pressure); **Dust Testing**—Uses test probes and dust chambers (e.g., for Level 6 dust-tight testing, a 1.0 mm diameter probe must not enter the enclosure); **Water Testing**—The second digit corresponds to specific test methods (Level 1: drip box/turntable test for 10 minutes; Level 2: enclosure tilted 15° in four fixed positions; Level 4: oscillating tube spray; Level 5: water jetting; Level 6: powerful water jetting; Level 7: short-term immersion at 1 meter for 30 minutes; Level 8: continuous submersion); **Labeling**—Product manuals must specify the IP rating (e.g., IP65, IP66, IP67, IP68); for IP68, the manufacturer’s specified depth and duration must be clearly noted (as there is no universal standard); **Verification**—When relying on existing reports, re-testing is required following structural changes (e.g., misaligned sealing rings, incorrect compression, inconsistent screw torque); **Integration**—System-level verification (connectors and seals must meet the same protection level; the IP rating must match the system’s weakest link). **Four Key Checks for Testing/Labeling**: Standardized oscillating tube spray, 1.0 mm probe for dust-tightness, specified depth/time for IP68, and re-testing after structural changes—these four checks ensure true compliance.
Conclusion
How should you select IP protection ratings for automation components?
The conclusion is to determine the rating based on five dimensions: digits, environment, components, potential pitfalls, and testing.
Digits—1st digit: dust protection 0–6 (5: dust-protected, 6: dust-tight); 2nd digit: water protection 0–8 (5: water jets, 6: powerful jets, 7: short-term immersion, 8: long-term immersion); standards: IEC 60529 (domestic equivalent: GB 4208). Environments—Indoor: IP20/30/40; humid/dusty workshops: IP44/54; outdoor/exposed: IP54+; rainy/water-pooling areas: IP65; harsh coastal areas: IP66/67; underwater: IP68 (depth specified). Components—Motors: IP23 (indoor ventilated), IP54 (standard workshop), IP55 (outdoor/dusty), IP65 (humid/harsh), IP67/68 (submersible pumps); Servo motors: IP54 (general workshop), IP65 (dusty workshop), IP67 (oil-mist/washdown resistant); Electrical cabinets: IP20/40 (indoor), IP54 (workshop), IP65 (outdoor), IP66 (powerful jet), IP67/68 (immersion); Actuators: IP65 (indoor), IP67 (outdoor/humid), IP68 (underwater). Pitfalls—IP67 tests immersion while IP66 tests powerful jets (choose IP66 for coastal areas); “X” means not specified (not necessarily Level 0); higher numbers often mean poorer heat dissipation; IP ratings do not cover impact, corrosion, or UV resistance; the rating is determined by the weakest link in the assembly. Testing—Standardized tests for dripping, oscillating tube spraying, and water jets; dust-tight requires no entry for a 1.0mm probe; IP68 requires specified depth and duration; re-testing required after structural changes; connectors and seals must match the rating.
Industry rule of thumb: Assess the environment first, then select the rating; higher numbers mean poorer heat dissipation;
the rating is set by the weakest link—”Three checks, one match” ensures the right protection.
