What the IP rating actually means
IP — Ingress Protection — is the international standard (IEC 60529) that classifies how well an enclosure resists dust and water. It's a two-digit code: the first digit is solids (dust), the second is liquids (water).
| Rating | Solids | Liquids | Typical use case |
|---|---|---|---|
| IP54 | Dust-protected | Splashing water | In-cabin fuse boxes, sheltered electronics |
| IP65 | Dust-tight | Low-pressure water jets | Chassis-mounted PDBs, exposed bus electronics |
| IP66 | Dust-tight | Powerful water jets | Bus/coach roof equipment, heavy-rain regions |
| IP67 | Dust-tight | Temporary immersion (1 m, 30 min) | Excavators, off-road construction, agricultural machinery |
Where IP65 / IP67 matters in your program
| Application | Typical exposure | Recommended IP |
|---|---|---|
| Heavy trucks & logistics | Chassis-mounted central PDBs see road spray, salt and washdown. | IP65 minimum; IP66 / IP67 for fleets in coastal or wet regions. |
| Construction machinery | Excavators, loaders and graders are pressure-washed, parked outdoors and run through dust storms — see NBX‑961 excavator integrated box. | IP67. |
| Buses & coaches | Roof equipment exposed to direct rain; chassis equipment to road spray. | IP65 minimum on chassis distribution boxes. |
| Agricultural machinery | Sustained dust ingress, occasional washdown. | IP66 / IP67. |
How we design for IP65 / IP67
Enclosure construction
Sealing starts with the enclosure split-line. We design with continuous gasket grooves, controlled compression and known-cure sealant compounds rather than retrofitting silicone after assembly. Wall thickness, rib geometry and venting strategy are chosen to maintain seal integrity through thermal cycling.
Sealed connectors
An IP-rated enclosure with a non-sealed connector is not actually IP-rated. NBX‑971 and the other IP67 variants ship with sealed automotive-grade connectors (Bussmann, Tyco/AMP Superseal, Delphi GT, Molex MX150) and matching gland or bulkhead seals at the harness exit.
Pressure equalisation
A perfectly sealed enclosure has a pressure-differential problem during thermal cycling: warm air expands, cold air contracts, and the gasket sees stress every cycle. We use semi-permeable ePTFE pressure-equalising vent membranes on outdoor enclosures so the inside pressure equalises without letting water through.
Validation
Every IP-rated NBX variant goes through dust and water ingress testing in our in-house environmental lab before mass production. The procedure follows IEC 60529, with results recorded and shared as part of the PPAP package.
Reference products with IP rating
- NBX‑971 Waterproof Central Distribution Box — IP67, sealed connectors, −40 to +85 °C, designed for heavy trucks and off-road equipment.
- NBX‑961 Excavator Integrated Box — sealed enclosure for construction-machinery duty cycles.
- NBX‑968 Sealed Electrical Box — outdoor sealed enclosure for chassis-mount applications.
Other NBX models can be specified with an IP65 / IP67 variant on a project basis. For non-standard sealing (extended immersion depth, IP69K pressure-washdown, etc.), please contact the engineering team directly via WhatsApp or email.
What we don't claim
We don't badge the entire NBX series as IP67. IP rating is a per-variant validation result — claiming a blanket rating across a 24-model family is misleading. The NBX models that are tested and shipped as IP67 are listed above; the rest carry the IP rating documented in their respective specs.