Cabling
Cabling is the axial helical twisting of 2 or more insulated wires, insulated wire assemblies (pairs, triads, etc.), and other components (fillers, strength members, binders, shield materials) into a core assembly. The components are arranged (cable core lay-up) to achieve:
- Minimal conductor strain,
- A flexible, circular cross section,
- Applicable electrical performance requirements, and
- The smallest possible outside diameter.
Cable Core Lay-up
To meet the above objectives, 3 key design factors are considered:
- Keep larger components in the center. Each successive component layer should employ progressively smaller components.
- Distribute components evenly throughout the core cross-section.
- Employ the least amount of fillers possible
Lay Length
Lay length is the axial distance of one 360° turn of any component in the core assembly. Typically the lay length should be 8-16 times the pitch diameter.
Pitch Diameter
Pitch diameter is twice the distance measured to the center of any conductor or component from the center of the cabled core.
Core Construction
Cable lay can be configured one of two ways:
- Unidirectional -- all components are twisted in the same direction, right-hand or left-hand.
Examples:
Bunched |
Unilay |
 |
 |
- Contrahelical -- each component layer lay direction is opposite from the preceding layer.
Example:
Equilay |
 |
Northwire Cabling Capabilities
Northwire has a full array of cabling equipment that can produce your most demanding shielded and unshielded cable core constructions up to 100 conductors and components, including:
- Single-Twist Cables
- Double-Twist Cables
- Double-Twist Twinners
- Planetary Cabler
- Taping & Binding Heads
- Foil Shield Servers
- Neutralizing Pay-offs
Northwire Design Assistance
We strongly recommend that you consult our technical staff when designing your cable core construction. Many factors influence cable core designs. Let our over 150 years cumulative design experience help you design your cable just the way you want it.
