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, pressure-washing and temporary immersion are part of normal duty. 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, routine wash-down, fording, or dust-heavy off-road duty. For the full rationale on what IP67 means in a commercial-vehicle context and how the sealing is achieved, see our waterproof IP67 distribution box guide; 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 (Bussmann, Tyco/AMP Superseal, Delphi GT) 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.

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 with PPAP package on program handoff. 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.