IP64 vs IP65 motor: choosing for washdown areas

Short answer: the second digit decides it, and the cleaning method decides the digit. IPX4 rates splashing water; IPX5 rates jets — IEC 60529 tests digit 5 with a 6.3 mm nozzle at 12.5 L/min. Fit IP64 motors on axes that only see dry cleaning, splash or condensate, and keep IP65 wherever a hose can reach the motor. Hot, chemical or high-pressure washdown sits past both digits, so there you shield the motor or move the electronics into a NEMA 4X / IP66 enclosure. Dust sits outside the decision, because both ratings are IP6x. Here is the whole decision, axis by axis, for your line.

What is actually different between IP64 and IP65?

Only the water digit differs. The 6 in both ratings is dust-tight against paper dust and lint. The second digit moves from 4, splashing water from any direction, to 5, water jets from any direction. That makes this a one-question comparison. Ask what can land on the motor during cleaning, and the choice falls out on its own, because the dust side is identical on both plates. If you are weighing a first-digit step instead — IP55 against IP65 — that is a different argument, and IP55 vs IP65 meaning for motor enclosures covers it.

What does IEC 60529 spray at each digit?

IEC 60529 tests the second digit 5 with a 6.3 mm nozzle delivering 12.5 L/min from 2.5 to 3 m for at least 3 min. Digit 4 gets only an oscillating spray that splashes water from every direction.

The jet test is a rinse-hose event: 12.5 L/min is about 3.3 gal/min, and a 6.3 mm nozzle is roughly 1/4 in across, one you could cover with a thumb. The digits tell you nothing about heat and chemistry, because the tests run clean water while real halls rinse with detergent. One digit up, 6, is a 12.5 mm nozzle at 100 L/min — a fire-hose-class jet. IPX5 vs IPX6 washdown protection compares those two for cleaning duty.

When is an IP64 motor good enough?

IP64 is good enough on any axis whose cleaning stays dry — vacuum, wipe, controlled air. It also covers axes that only catch splash, mist or condensate drifting from neighboring equipment, which is most conveyor axes on a diaper or tissue line. Dry cleaning and stray wetting are exactly what digit 4 rates. On most servo families the two protection options share one rated-data block — 0.82 kW, 3 Nm, 3000 rpm on one compact size — so torque never picks the variant here; exposure does. Keep blow-down nozzles off the shaft exit either way, because a directed air jet drives lint into the seal lip whatever the plate says.

When does the axis need IP65?

Move up to IP65 wherever a person with a hose can point water at the motor: rinse-down between shifts, hose cleaning of the frame around a knife axis, or any axis mounted below a spray header. The shaft seal is the weak point of any motor. It seals on a rotating surface while the rest of the housing sits static and gasketed, and a hose delivers exactly the load digit 5 rates: water arriving with direction and volume.

Mounting sets how much reaches the seal. Shaft up, liquid pools on the flange around the exit; shaft down, it drains along the housing. Motor coolant shields and pooling risks works through the pooling cases. Read the drive-end line on the data sheet for your orientation too: some families rate the flange a digit above the body, IP67 against IP65 in one example. Set the rotatable connector so the cable exits at the bottom, and hose water runs off the coupling.

What cleaning exceeds both ratings?

Hot, chemical and high-pressure washdown exceeds both digits. IPX5 rates a clean-water jet at 12.5 L/min, a plant rinse arrives at 60 C [140 F] with detergent, and a 100 bar [1450 psi] pressure washer belongs to IPX9, hot high-pressure spray. Both digits are ingress ratings on clean water alone. They tell you nothing about temperature or chemistry, and hot detergent is what actually ages a seal in a washdown hall. In those areas, move to a washdown-duty motor family or shroud the standard motor out of the spray line. For the enclosure side of the same hall, washdown water temperature and your enclosure carries the temperature numbers. If your question has widened to sensors that get cleaned in place, IP65 vs IP66 tunnel sensor selection for cleaning walks the next jet size up.

What rating does the control enclosure need?

Put the drive and control electronics in an enclosure rated NEMA 4X / IP66 — ours are rated by the manufacturer and not UL listed — because the panel sees the same cleaning the motor does, and usually more of it. The panel hangs in the same hall the hoses work in. In US installations, NEC 110.28 states that IP ratings are not a substitute for enclosure type ratings, so write the type on your spec — 4X for hose areas — with IP66 alongside it for international documents. What a UL 50E listing covers explains the listing side of that sentence. Where sanitizers and chlorides fly, make it 316L stainless wall-mount enclosures, which shrug off washdown chemistry that pits 304.

The weakest part sets the assembly rating: glands and any breather valve need IP66 or better, and one IP54 breather drops the whole box to IP54. Then size for heat rather than rail count. Stainless walls pass about k = 3.7 W/m²K, so take a 20 x 16 x 6 in 316L wall-mount enclosure [508 x 406 x 152 mm]. Its 0.69 m² of surface at 3.7 W per square metre per kelvin sheds about 13 W for a 5 C [9 F] rise at 35 C [95 F] ambient. A drive losing 150 W in that same box gives a 59 C rise, so 94 C inside — take the next size or a heat exchanger, and work it through with motor starter and contactor enclosure sizing.

What else changes when you swap variants?

In many servo families the lower-IP variant also carries the lower-resolution encoder — for example 20-bit against 24-bit, 1,048,576 against 16,777,216 counts per revolution, a factor of 16 — so read every line of the data sheet, not only the protection class. The order code can change the encoder at the same time as the rating, and that changes your resolution. Lock out the drive and prove the motor de-energized before you open the feedback connector. Then let the drive re-read the electronic nameplate and re-run motor identification after the swap.

Worked example, a cut-to-length knife. The motor turns a 100 mm [3.94 in] diameter drum — 314 mm [12.4 in] of product per revolution — through a 5:1 belt.

• 20-bit encoder: 2^20 = 1,048,576 counts/rev; times 5 = 5,242,880 counts per drum turn; divided by 314 mm = 16,694 counts/mm.
• 24-bit encoder: 2^24 = 16,777,216 counts/rev; times 5 = 83,886,080; divided by 314 mm = 267,155 counts/mm — sixteen times finer.

The knife holds 0.1 mm [0.004 in], so the 20-bit encoder still lands 16,694 × 0.1 = 1,669 counts inside one tolerance band — ample margin, and the swap is safe on this axis. Put the same two encoders 1:1 on a 400 mm [15.7 in] roll holding 0.01 mm [0.0004 in]: 2,621 against 41,943 counts/mm, or 26 against 419 counts per band. On that axis the encoder decides the variant, not the water digit. Both are single-turn absolutes, so behavior after a power cycle and the homing routine stay the same.

Which motor goes on which axis?

Assign IP64 to dry-cleaned and splash-only axes, IP65 to anything a hose reaches, and treat hot or chemical washdown as a motor-family change plus a NEMA 4X / IP66 panel. That one rule covers a whole converting line. Walk the machine with the cleaning procedure in hand and give every axis one row before you order, because a mixed line carrying all four rows is normal.

Write the enclosure line with material, rating and cutouts: a 16 x 16 x 8 in 316L box takes a compact drive with room to spare for the starter and feeder. Custom work is delivered in 10 business days, counted from your approval of the drawing. Still sizing? The enclosure selector narrows it by environment and module count, and the IP rating chart keeps every other digit straight.

Enclosures in this article

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