Custom Waterproof Cable Harness RFQ: Length and Branch Data

Scope and boundaries

Applies to buyer-prepared RFQs for custom waterproof cable assemblies on circular connector families such as M8 through M29. The available LLT guide and technical notes define what information a custom harness RFQ should contain and the applicability limits of published ratings, but they do not include prices, lead times, minimum order quantities, or model-specific drawings, so those items must be confirmed for each project. No parameter table ships with this article; request the datasheet per part number.

Why two harness quotes rarely price the same thing

A supplier can only price what is defined. When an RFQ gives a series name, a rough length, and the word 'waterproof' — and nothing more — each respondent fills the gaps differently, and the prices that come back are accurate for different products: one assumes an overmolded cordset, another a field-assembly kit, a third adds a branch the sketch never showed. Comparing those totals is wasted effort. The fix is to pin down the variables that actually change cost and responsibility — interface, load, cable, geometry, environment, acceptance documents — before asking anyone to quote.

Sources: LLT selection guide

Fix the mating interface before the cable

Begin with the interface drawing or the exact mating part number, plus pin count and wiring definition — the first items LLT's selection guide asks for on a custom harness. A series name such as M8, M12, or M16 does not by itself establish intermateability: coding, locking structure, pinout, and the mating model all have to match. Pin or socket contact gender is specified separately from housing and mounting form, whether front-panel, rear-panel, flange, or in-line. If the harness carries signals or data, add shielding and transmission requirements to the list.

Sources: LLT selection guide · Technical applicability

State the load per contact group, not per device

Give working voltage, current, and whether each line is power or signal. On mixed configurations such as 3+2, each contact group carries its own current, voltage, and wiring specification; the group ratings are never added into one device-level figure. Conductor cross-sectional area in mm², wire gauge in AWG, and cable jacket outer diameter in mm are three separate specifications. Conductor size supports an initial screening against catalog limits and AWG follows the catalog's gauge correspondence, but the jacket OD must still fall inside the clamp's sealing range — a conductor that fits can sit in a cable that does not seal.

Sources: LLT selection guide · Technical applicability

Dimension the harness: length, branches, outlet direction

This is where harness RFQs go vague most often. State cable length with a tolerance, not a nominal figure. Give branch positions measured from a defined reference, the outlet direction at each connector, and the end treatment at every termination — stripped, tinned, ferruled, or a second connector. If the branch breakout point on the main run is not dimensioned and toleranced in the RFQ, ask the supplier to quote against a marked drawing or an existing sample before comparing prices; if it is defined, quotes can be compared on the same configuration. LLT notes that an existing sample or drawing can anchor the engineering evaluation when the routing already exists inside the machine.

Sources: LLT selection guide

Say which scope of supply the price should cover

A connector alone, a connector with cable attached, and a complete branched harness are three different scopes. Field assembly lets the routing length be fixed during installation; an overmolded harness finishes length, wiring, and end structure before delivery. The choice depends on routing space, maintenance practice, and batch assembly flow, and on whether the selected model supports the intended termination. State explicitly who supplies the cable and who owns sealing at the panel cutout and at any unterminated far end. A low quote may simply exclude work you assumed was inside.

Sources: LLT selection guide

Write environment and verification conditions into the RFQ

IP67 means dust-tight construction and short-term immersion under defined test conditions, and it holds when the connector is correctly mated and locked, seals are intact, the specified cable OD is used, and installation sealing is completed. Long-term immersion and high-pressure washdown are different test conditions: provide water depth, duration, temperature, medium, and cleaning method, and select a configuration with corresponding verification records. Figures such as UV resistance of 1,000 hours or more and salt fog of 480 hours or more are supplier-declared performance information for applicable configurations, and the declared durations do not convert into outdoor service years. Dust protection to IP6X does not qualify a connector for explosive dust atmospheres.

Sources: Technical applicability · IEC 60529 — Degrees of protection provided by enclosures · LLT selection guide

Acceptance documents, certifications, and quantities

Name the acceptance documents expected with delivery: assembly drawing, wiring definition, and the verification records matching your environment list. Certifications apply per SKU — UL 2238, UL 1977, CE, TÜV, and SAA files follow the certificate's stated models and ratings, not the catalog family — and UL 94 V-0 is a flammability rating for a plastic material, not a product certification for the finished connector. State quantities by phase and the delivery split to be priced. Price, lead time, and minimum order quantity are not published here; mark them as items the quotation must answer.

Sources: LLT selection guide · Technical applicability

Checklist to send with the RFQ

Each line below removes a clarification round:

With these items fixed, quotations land on one configuration, and any gap that remains gets stated as pending instead of being silently assumed. Submit the list with your drawings or sample; LLT evaluates cable and connector together.

• Interface drawing or exact mating part number, with pin count and wiring definition
• Working voltage and current per contact group; power versus signal use
• Conductor size in mm² or AWG, cable jacket OD in mm, and jacket material
• Cable length with tolerance, branch positions from a defined reference, outlet direction per connector
• End treatment at each termination: stripped, tinned, ferruled, or second connector
• Mounting form and panel data where applicable: cutout, panel thickness, front or rear mounting
• Environment: rain, immersion, washdown, UV, salt fog, temperature range
• Required verification and certification documents for the sales market
• Quantities by phase and the delivery scope to be priced
• Existing sample or marked drawing, if available, as the evaluation baseline

Sources: LLT selection guide

Frequently asked questions