Connector Cable Diameter and Conductor Cross Section Checks

Scope and boundaries

Applies to matching cables to waterproof cable connectors and harness assemblies, field-assembled or overmolded, where a conductor size and a jacket OD must both be verified against one chosen configuration. The sources define the two-dimension rule and the screening logic, but they do not list per-model sealing ranges or accepted cross sections, so no specific connector-cable pairing can be confirmed from this article alone. Sealing ranges, conductor ranges, termination methods, torque and strip dimensions must come from the documents for the exact part number before a build is released.

Two measurements, two different jobs

Start with the two numbers your cable actually carries. Conductor cross section is specified per core in mm², the cable outer diameter is the jacket diameter in mm, and the two units must not be interchanged. AWG is a wire-gauge designation for conductor size, not a unit of length or area; where the catalog gives a verified AWG-to-mm² correspondence it can be used for comparison, but the jacket OD stays a separate entry in millimetres. Conductor cross section and cable outer diameter are two independent checks: the cross section screens contact current capacity, while the outer diameter must fall inside the connector's specified sealing range, and passing one check says nothing about the other.

The two numbers meet different parts of the connector. The cross section meets the contact and the termination; the jacket OD meets the rear clamp and the seal. Cables with the same conductor cross section can have different outer diameters because core count, insulation and jacket construction differ, so conductor size and cable OD must be checked separately. A connector that accepts your conductor can still reject the cable at the seal — and a cable that fits the seal says nothing about contact capacity.

Sources: Technical applicability · LLT selection guide

What the cross section decides — and what it does not

Rated current is stated per contact, or per a specified contact group, for the selected configuration; rated voltage follows the insulation structure. When several cores carry current at once, the conductor cross section, ambient temperature and heat dissipation all influence temperature rise and the current the assembly can sustain. Treat catalog ratings as an initial screen: the final choice has to be checked against the specification sheet and a temperature-rise verification under the actual working conditions.

Upsizing the wire does not upsize the connector: between conductor and load sit the contact, the termination method and the rating of that exact configuration. In mixed layouts such as a 3+2 power-plus-signal arrangement, each contact group carries its own current, voltage and wiring specification. The group ratings cannot be added into one machine rating, and each group is matched to its own conductor size.

Sources: Technical applicability

What the jacket OD decides — sealing and clamping

The outer diameter does no electrical work; it decides whether the cable clamp and seal close on the jacket as designed. An IP67 assembly holds when the connector is correctly mated and locked, the seals are intact, a cable of the specified outer diameter is fitted and the installation sealing is completed. The unmated port, the far end of the cable and the device cutout each need separate protection measures.

The fit rule is an interval, not a ceiling: the cable OD must fall inside the sealing adaptation range of the chosen configuration, and confirming only that the product's upper limit exceeds your cable OD is not enough. If the jacket OD is outside the sealing range for the chosen configuration, the IP67 condition is not established even when the conductor fits the contact. A cable below the range may leave the seal under-compressed; a cable above it may not seat at all.

Sources: Technical applicability · LLT selection guide

If one check passes and the other fails

If the catalog cross-section limit accepts your conductor but the cable jacket OD falls outside the sealing range for that configuration, stop and request the sealing data for the exact part number — do not assume a different seal can be swapped in. Replacing seals, trimming parts or re-terminating a cable all need a documented method for that model; where no such document exists, they are open items, not options.

The reverse case works the same way: a cable that fits the seal but sits outside the contact's conductor range, or that pushes the configuration past its temperature-rise limits at your duty cycle, is not a valid pairing either. When both numbers fall inside the documented ranges for the exact part number, move to sample verification under the real load and environment before releasing the build. A mismatch at this stage means unconfirmed, not broken — do not force the assembly together.

Sources: Technical applicability

Screening candidates without borrowing ratings

Catalog figures belong to the configuration they are printed with. A series headline current, an accepted conductor range or a sealing interval does not automatically transfer to every SKU in the series, so each candidate part number is screened on its own data: does its contact range cover your conductor size in mm² or the catalog AWG correspondence, and does its sealing range cover your cable OD? Any later cable substitution re-opens both checks, because a new construction at the same cross section can change the OD.

This article carries no per-model parameter tables. Before a pairing is released, the configuration page of the LLT catalog and the specification sheet for the exact part number still need to supply the conductor range, the sealing range and the termination data; until then the screening result is compatible-so-far, not confirmed.

Sources: LLT public connector catalog · Technical applicability

Send the cable and the duty together

A harness pairing can be checked in one pass when the cable and the duty arrive in the same inquiry.

An existing sample or drawing is a valid starting point, and cable and connector can be evaluated together rather than as separate purchases. Field-assembled connectors let length be fixed on site; overmolded harnesses finish length, wiring and end structure in advance. The choice follows routing space, maintenance practice and assembly flow, plus the termination methods the chosen model supports.

• Mating part number or interface drawing, with core count and wiring definition
• Working voltage and current per circuit, and which cores carry power at the same time
• Conductor cross section per core in mm², or AWG with its correspondence basis
• Cable jacket outer diameter in mm, and the jacket material
• Cable length and tolerance, branch positions, exit direction and end treatment
• Environment and verification needs: rain, immersion, washdown, UV, salt spray, temperature range

Sources: LLT selection guide

Frequently asked questions