NBX-971 Waterproof Central Distribution Box (IP67)

Overview

The NBX‑971 is the sealed, IP67-rated member of the NBX central power-distribution family — a waterproof distribution box for the mounting points a standard body-cavity PDB cannot reach: the chassis rail, the engine bay, an exposed cab-side bracket, or any position on off-road and construction equipment where dust, spray and temporary immersion are part of normal duty. Direct high-pressure wash-down is a separate question from IP67 and is confirmed per programme rather than assumed from the rating. It consolidates the vehicle's fuses, relays and load-feed circuits into one sealed enclosure rated −40 to +85 °C and 9–32 VDC, so a single box serves both 12 V and 24 V architectures.

Most high-circuit NBX siblings — such as the NBX‑957, NBX‑953, NBX‑958 and NBX‑970 — are selected primarily by circuit count and harness capacity, with IP54 body-cavity builds and programme-specific sealing options. The NBX‑971 is selected first by the mounting environment: when the box must sit outside the protected body cavity and needs a validated IP67 enclosure with sealed connectors. The sealing approach behind the IP67 rating is detailed below.

When you need a sealed IP67 distribution box

IP67 sealing is worth specifying only when the mounting environment demands it — chassis-rail or engine-bay placement, fording or standing water, or dust-heavy off-road duty. Cleaning duty is a separate line in the specification rather than part of this one, for the reason given above. What the IP67 digits cover in a commercial-vehicle context is on the IP ratings guide; how this chassis box is gasketed, vented and connector-sealed is in the waterproof IP67 distribution box notes.

If the box will instead sit in a dry, protected body cavity, choose a higher-circuit IP54 sibling (NBX‑958 / NBX‑970 / NBX‑953) sized to your circuit count. For an excavator or off-road machine with a sustained high-vibration duty cycle, the NBX‑961 excavator integrated box is the purpose-built sealed platform; the NBX‑971 is the general-purpose sealed central box for road-chassis programmes.

Engineering details

The IP67 rating is achieved through a coordinated set of design choices, not just a label: continuous gasket seal at the split-line, controlled compression, sealed automotive connectors at the harness exit — the standard build uses three Deutsch housings, with Bussmann, Tyco/AMP Superseal or Delphi GT specified where a programme already stocks them — and a semi-permeable vent membrane that equalises internal pressure across thermal cycling without admitting water. See our IP65 / IP67 protection page for the full design rationale.

• IP67 — dust-tight + temporary immersion, validated in-house
• Sealed automotive connectors with matched wire-side seals
• Pressure-equalising vent membrane for thermal-cycle robustness
• Same circuit-mapping flexibility as the body-mount NBX siblings

Mechanical layout

Mating connectors

The standard NBX-971 build uses 3 sealed Deutsch harness-side connectors. Wire-side seals, terminal P/N and pin-out are confirmed against the customer harness drawing at quotation. Which half of each joint you are ordering, and why terminals and seals are quoted separately from the housing, is set out in the automotive connector guide.

Fuse & relay configuration

Standard build, customised on a programme basis:

Built-in load functions

Programme-specific load mix — the NBX-971 reference build covers the following 8 vehicle-electronics functions, sized for sealed body / chassis programmes including construction-machinery cabs:

• Engine kill / shutdown control
• Headlight control
• Boom-light control
• Horn control
• Wiper control
• Engine control
• Air-conditioning (HVAC) control
• Fuel-pump control

Manufacturing & testing

Manufactured under IATF 16949. PPAP deliverables and the submission level are agreed against the customer-specific requirements and the released drawing revision. IP testing follows IEC 60529 in our in-house environmental lab; reports are part of the program documentation.

Related models & how to ask

Sister sealed models include the NBX‑961 excavator integrated box and the NBX‑968 sealed electrical box. For unsealed body-mount programs, choose the NBX‑957. If the chassis-rail position sees water jets but not immersion, the IP65 NBX‑969 chassis distribution box is sufficient. Send chassis drawings via the contact page.