Industrial Automation
- IP65 protects against dust and water jets — the motor can sit under washdown spray and tool coolant, but not under standing water. The 5 in IP65 is a 6.3 mm nozzle at 12.5 L/min for at least 3 minutes, per IEC 60529.
- IP67 protects against the same dust plus temporary immersion in water up to 1 metre deep for up to 30 minutes. The 7 in IP67 is a 30-minute bath with the motor's lowest point 1,000 mm below the surface.
- The cost difference in the same frame size is roughly 25% to 40%. IP67 is not "better" — it is "more sealed," which costs money, costs thermal performance, and is unnecessary on the majority of indoor industrial applications.
- Pick IP65 for most general-purpose industrial service. Pick IP67 when the motor sits in a condensate pool, on a daily washdown line, or anywhere standing water can reach the housing.
- The IP number does not change peak torque, but it does change continuous torque. A sealed motor in the same frame delivers roughly 5% to 10% less continuous torque than an IP54 or open-ventilated version, because heat dissipation is harder through a sealed enclosure.
A procurement officer at a packaging OEM in Ontario called last quarter to ask why the IP65 Servo Motors on his new line were failing inside eighteen months, while the older IP54 motors on the previous line had run for ten years. The answer was not the IP rating; it was the environment. The new line was in a washdown room that flooded the cable trays every sanitation cycle, and an IP65 motor's "protected against water jets" rating does not protect against a cable tray that empties onto the motor's housing once a week.Higher IP number is not the right reflex. The right reflex is to identify the actual failure mode and choose the rating that addresses it.
This guide is written from the perspective of our IP65 servo motor product range and the working design notes for the Physis motor protection design, which is the harsh-environment Servo Motor we ship most often for food and beverage, machine tool, and outdoor applications. The decision framework below is independent of any single product — it applies whether you source from us or from another vendor — and the practical takeaway is that the IP code is a test result, not a marketing slogan, and the test that the motor passed has to match the exposure that the application delivers. If you need a configuration outside our standard catalog, ourengineering team can review your environment against the IP test specifications.
What the Two Numbers Actually Mean Under IEC 60529
The IP code is published in IEC 60529, "Degrees of protection provided by enclosures (IP Code)," and the standard's official summary is on the IEC's IP ratings page. The code is two digits after the letters "IP," and each digit is a separate test. The first digit is solid-particle protection; the second is water protection. The digits do not add; you cannot infer IP67 from IP65 plus IP65.
The first digit (6) is the same for both IP65 and IP67. It is the highest solid-particle rating on the IEC scale, and the test is dust-tightness: the motor is placed in a dust chamber and exposed to circulating talcum powder for 8 hours. No dust ingress that could interfere with operation is permitted. The dust test is binary — a motor either passes the 8-hour dust chamber or it does not. There is no IP65-grade dust; dust is fully excluded at this rating or the motor fails.
The second digit is where the two ratings diverge. IP65's "5" is the water-jet test: a 6.3 mm nozzle spraying water at the motor at a flow rate of 12.5 litres per minute, with the nozzle 3 metres away, for at least 3 minutes. The test passes if no water interferes with operation or reaches live parts. IP65 is rated for incidental splashes, rain, and directed spray — but not for water under pressure or temporary immersion. IP67's "7" is the immersion test: the motor is submerged with its lowest point 1,000 mm below the water surface and its highest point at least 150 mm below, for 30 minutes. The test passes if no water enters in harmful quantity.
| Test parameter | IP65 | IP67 |
|---|---|---|
| Solid particle protection | Dust-tight (8-hour dust chamber) | Dust-tight (8-hour dust chamber) |
| Water test description | Water jet, 6.3 mm nozzle, 12.5 L/min | Temporary immersion, 1 m depth, 30 minutes |
| Water pressure | ~30 kPa at nozzle (low-pressure jet) | Hydrostatic at 1 m (~10 kPa, static) |
| Test duration | 3 minutes minimum | 30 minutes |
| What it does NOT cover | Immersion, high-pressure spray, steam | Sustained immersion beyond 30 min, high-pressure CIP washdown |
| Typical environment | Tool coolant spray, splashing, rain, indoor washdown | Standing water, condensate pools, outdoor mounting, daily washdown |
The most common mistake is to read the IP code as a single number — "an IP rating of 67 is more than IP 65, so 67 is better." The two digits are independent test results, and "67" only means "passes the immersion test," not "passes the jet test better than IP65." An IP67 motor has passed the same jet test an IP65 motor has passed; it has also passed an additional immersion test.
The Cost-Cycle Trade-Off That Decides Most Applications
Every decision between IP65 and IP67 in the same motor frame reduces to one question: is the extra cost of IP67 worth the avoided motor replacement? In the same frame size, IP67 costs roughly 25% to 40% more than IP65, and that premium is paid in two currencies: money up front, and continuous torque delivered. The seals that make a motor IP67 trap heat inside the enclosure, and a sealed motor in the same frame size will deliver roughly 5% to 10% less continuous torque at the same ambient temperature, because the heat path out of the stator is reduced. The peak torque rating is unchanged because peak ratings are thermal-mass-limited for short transients; the continuous rating, the rated speed at continuous load, and the S1 duty cycle envelope are the affected numbers. Rockwell Automation, Bosch Rexroth, and most motor vendors publish a separate torque curve for the IP65/IP67 frame in the datasheet; the IP54 curve should not be assumed to apply.
The cycle-life dimension is more subtle. A sealed motor runs cooler in the stator during peak transients (because the seal reduces convective heat transfer to the air, the heat stays in the copper briefly rather than being blown away by an open-vent fan), but it runs hotter during continuous duty. The net effect on bearing grease life and insulation class life is application-dependent. On an application with a high duty cycle and few peaks, IP65 will outlast IP67 because the IP67 motor's continuous-torque de-rating forces it to operate closer to its thermal limit. On an application with many short transients and a low duty cycle, IP67 may outlast IP65 because the seal is keeping contamination out of the bearing cavity, which extends the bearing L10 life.
Three Application Tiers Where the Choice Is Obvious
The IP selection looks ambiguous in the abstract and obvious in concrete applications. The three tiers below cover roughly 90% of the decisions we see in the field.
Tier 1 — General Industrial (Pick IP65, Skip IP67)
Machine tool spindles and feed drives, packaging machines, material handling conveyors, palletisers, pick-and-place, assembly automation, robotics inside a clean cabinet. The motor lives inside an enclosure, behind a guard, or under a shroud. It sees occasional splashes, tool coolant spray, and oil mist, but it does not see standing water, condensate pools, or washdown. IP65 is the right call. IP67 is over-specified and will cost 25% to 40% more for no benefit, plus the continuous-torque penalty makes the motor run warmer and reduces insulation life. The standard catalog line at the major motion-control vendors — the catalogue series that ships out of stock — is IP65 with a TENV (totally enclosed non-ventilated) frame, which is the rating we and most of our peers quote as the default for general-purpose industrial service.
Tier 2 — Washdown, Outdoor, Condensate (Pick IP67)
Food and beverage lines, dairy and pharmaceutical packaging, outdoor mounting on construction equipment or marine vessels, anywhere a cable tray or process pipe can drip condensate onto the motor, anywhere the motor is mounted in a low spot of the machine where water can pool. IP67 is the right call. The IP65 water-jet test does not cover standing water, and an IP65 motor in a condensate pool will fail the seal long before the IP67 motor does. The extra cost is small compared with the cost of a line stop on a 24/7 packaging line, and the IP67 seal geometry is designed to be serviceable — the seal kits can be replaced during scheduled maintenance without replacing the motor.
Tier 3 — Hygienic / CIP Washdown (Pick IP69K, Not IP67)
Dairy, beverage, pharmaceutical, and meat-packing lines that run Clean-In-Place (CIP) washdown with hot water at 80°C and 80 to 100 bar of pressure. IP67 is not sufficient because the CIP pressure and temperature exceed IP67's test envelope. IP69K, defined in ISO 20653 and adopted in DIN 40050-9, is the right rating for hygienic washdown.Most general-purpose Industrial Servo Motors do not have IP69K ratings; the rating is reserved for hygienic-design motors with stainless-steel housings, smooth surface finishes that drain water and resist bacterial growth, and food-grade seal materials. The IP69K motor also costs roughly 2× to 3× an IP65 motor in the same frame, which is why it is not the default for general industrial use.
Other IP Ratings You Will See on Datasheets
Three adjacent ratings are worth understanding so you can read a datasheet without confusion. IP54is the standard indoor industrial rating: dust-protected (not dust-tight) and protected against splashes from any direction. IP54 is the default for cabinet-mounted servo motors and is the rating most general-purpose Industrial Servo Motors carry.IP55 is the slightly upgraded version: dust-protected (same as IP54) and protected against water jets (same nozzle as IP65 but at lower flow). IP55 is uncommon in servo specifications; IP65 is the more frequently quoted jet-rated version. IP66 is dust-tight plus powerful water jets (12.5 mm nozzle at 100 L/min), used for marine-deck and heavy-industrial washdown where the jet pressure exceeds IP65's test.
Outside IEC 60529, the most commonly confused rating is NEMA 4X, which is the NEMA enclosure type that approximates IP66 with a corrosion-resistance requirement (typically 304 or 316 stainless). NEMA 250 is the US parallel standard to IEC 60529 and is sometimes required by spec on North American projects. The two systems are not directly interchangeable — NEMA ratings add corrosion, icing, and oil-resistance tests that IEC 60529 does not — but a NEMA 4X enclosure is approximately equivalent to IP66 in water and dust terms, and is the standard rating for food, beverage, and pharmaceutical washdown in North America. NFPA 79, the US electrical standard for industrial machinery, is the third reference that governs how the IP rating interacts with the wider machine wiring and grounding spec. The fourth reference that occasionally appears in North American specs is the UL standards index for enclosures and motor housings — UL 50 and UL 50E for enclosures, UL 1004 for rotating electrical machines — which adds a third dimension (UL listed / recognised) on top of the NEMA or IEC rating.
How to Read a Servo Motor Datasheet's IP Section
Three numbers appear in the IP section of most Servo Motor datasheets, and most procurement teams read only the first.The first is the shaft-seal IP rating (typically IP65 for general-purpose, IP67 for harsh-environment). The second is the connector or cable-gland IP rating when the motor is plugged in. The third is the rating of the cooling fan when the motor has an integrated fan (most IP65 and IP67 motors do not — they are TENV, totally enclosed non-ventilated — but some high-power ratings carry a separate fan that may be a different IP rating).
The number that matters in operation is the assembled-system rating, not the bare-motor rating. A servo motor rated IP67 with a cable gland rated IP65 will fail at the gland, not at the motor housing. A servo motor rated IP67 with an IP54 fan will fail at the fan shaft, not at the housing. Spec the IP rating at the system level, including the connector, the cable, and the fan, and make sure the cable gland and connector spec on the bill of materials matches the motor spec. Most field failures that are blamed on the motor are actually failures at the cable gland or the connector — a point the datasheet hides because it quotes the motor-side rating only.
What the Vendor Will Not Tell You
Three caveats worth knowing before signing the PO. The first is that IEC 60529 does not test for chemical compatibility. The water-jet test uses clean water, and a motor that passes IP65 with clean water can still fail in a real plant where the splash is detergent, cutting fluid, hydraulic oil, or caustic washdown solution. If the application involves chemical exposure, the seal material specification matters as much as the IP rating. Fluoroelastomer (FKM) seals resist most cutting fluids and detergents; EPDM resists steam and some acids; nitrile (NBR) resists oil but not ozone. The vendor's datasheet usually lists only "NBR" by default, and chemical exposure is treated as out-of-scope.
The second is that IP rating is tested on a new motor. The seals on a brand-new IP65 motor pass the test; the seals on a five-year-old IP65 motor that has been through 1,000 thermal cycles, ten belt slips, and two coolant changes may not. The seal is a wearing part, and the IP rating is a one-time factory test result. The right interpretation is "rated IP65 at first commissioning, with seal-kit replacement on the maintenance schedule." A motor that has not had its seals inspected or replaced in five years is operating at a degraded rating, and the actual protection in the field may be closer to IP54.
The third is that IP rating does not capture thermal performance. As noted above, IP65 and IP67 motors in the same frame deliver less continuous torque than IP54 motors, but the de-rating varies by vendor and is rarely highlighted in marketing materials. The SMMA (Small Motors & Motion Association) publishes guidance on how to compare torque curves across ratings; the working rule is to ask the vendor for the continuous-torque curve at the specific IP rating the motor will carry, not the IP54 curve from the catalog.
The Procurement Decision Checklist
The decision rule we hand to new procurement teams. It is short on purpose:
- Environment exposure: identify whether the motor sees splash, jet, immersion, or CIP washdown. Match the second digit to the exposure.
- Continuous duty cycle: if above 60%, IP65 is almost always the right call; the IP67 thermal penalty will shorten insulation life.
- Replacement cost vs motor cost: if the motor is on a 24/7 line where replacement requires a stop, the IP67 premium pays for itself the first time the seal saves the motor.
- Chemical compatibility: confirm the seal material against the chemicals in the environment; standard NBR may not be enough.
- Connector and cable gland: verify the assembled-system IP rating, not just the motor-side rating.
- Thermal de-rating: ask the vendor for the continuous-torque curve at the IP rating being purchased.
- Seal maintenance schedule: plan a 3- to 5-year seal-kit replacement interval; the IP rating is a one-time test result, not a permanent state.
Need to size an IP65 or IP67 servo motor for a specific environment? Send us the motor frame size, the continuous duty cycle, the peak-to-rms torque ratio, the chemicals in the environment, and the connector spec. We will recommend an IP rating from our standard servo motor range, confirm the continuous-torque curve at that rating, and quote the Physis motor configuration that fits the application.
Frequently Asked Questions
What does IP65 mean on a servo motor?
IP65 means the motor enclosure is fully dust-tight (the '6') and protected against water jets from any direction (the '5'). Under IEC 60529 the water-jet test is a 6.3 mm nozzle spraying roughly 12.5 litres per minute at the motor for at least 3 minutes. IP65 is the most common rating for general-purpose industrial servo motors mounted inside a cabinet or under a machine shroud — it handles washdown splashes and tool coolant spray but is not designed for temporary immersion.
What does IP67 mean on a servo motor?
IP67 means the motor is fully dust-tight (the '6') and protected against temporary immersion in water up to 1 metre deep for up to 30 minutes (the '7'). Under IEC 60529 the immersion test submerges the motor for 30 minutes with the lowest point 1,000 mm below the water surface and the highest point at least 150 mm below. IP67 is the right rating when the motor is mounted in a low spot of the machine where condensate pools, on outdoor equipment exposed to standing water, or on food and beverage lines where daily high-pressure washdown and occasional flooding happen.
Is IP67 better than IP65 for a servo motor?
Higher IP number is not automatically better. IP67 costs roughly 25% to 40% more than IP65 in the same frame size, and the seal geometry that makes IP67 work can reduce the motor's continuous-torque rating by 5% to 10% because heat dissipation is harder through a sealed enclosure. The right answer depends on the environment, not on the IP number. A servo motor mounted inside an IP54 control cabinet in a clean factory does not need IP65, much less IP67. A motor mounted under a beverage line that sees daily washdown needs IP67 because IP65 will fail on immersion in standing water.
Can a servo motor be IP69K?
Yes, IP69K is a separate rating defined in ISO 20653 (road vehicles) and adopted by DIN 40050-9 for high-pressure, high-temperature washdown. IP69K subjects the motor to 80°C water at 80 to 100 bar sprayed from four angles for 30 seconds each. The rating exists for food, beverage, pharmaceutical and dairy lines that use Clean-In-Place (CIP) washdown, where IP67 is not sufficient because the wash pressure exceeds IP67's immersion test. Most general-purpose industrial servo motors are not IP69K; the rating is reserved for hygienic-design motors with stainless-steel housings.
Does a higher IP rating affect servo motor torque?
Yes, in continuous duty. The seals that make a motor IP65 or IP67 trap heat inside the enclosure, and a sealed motor in the same frame size will typically deliver 5% to 10% less continuous torque than an IP54 or open-ventilated motor at the same ambient temperature, because the heat path out of the stator is reduced. The peak torque rating is unchanged because peak ratings are thermal-mass-limited for short transients, but the continuous rating, the rated speed at continuous load, and the S1 duty cycle thermal envelope are all affected. Motor manufacturers publish a separate datasheet line for IP65/IP67 ratings; never assume the IP54 curve applies.
How do I decide between IP65 and IP67 for a servo application?
Start with three questions. (1) Is the motor exposed to anything more than splashing water — puddles, condensate pools, washdown spray, or temporary immersion? If yes, you need IP67. (2) Is the motor mounted inside a control cabinet or under a machine shroud with no direct water path? If yes, IP54 or IP65 is enough. (3) Is the environment food, beverage, pharmaceutical, dairy, marine, or outdoor with weather exposure? If yes, default to IP67 (or IP69K for high-pressure CIP washdown). The cost difference between IP65 and IP67 in the same frame is roughly 25% to 40% — well worth paying on a motor whose replacement requires a line stop.