TYPE 451

Type 451 is a Class 1, composite screened, three-core trailing cable for open cut and surface mining at 3.3–33 kV. It shares the same power core architecture as Type 450 — centre filler, three individually composite-screened XR-EP-90 insulated power cores, two interstitial earth conductors, and a reinforced XHD outer sheath — but differs in one key respect: the pilot conductor is reduced in cross-section compared to Type 450.
The reduced pilot (75/0.40 mm or 99/0.40 mm depending on size) is sized to carry pilot protection and monitoring signals only, not the current capacity of the full-size pilot in Type 450. Where the outer interstices are not fully occupied by the three covered conductors, the outer sheath fills the remaining space directly — no separate shaped elastomer fillers are specified for Type 451 (unlike Type 450).
Both earth conductors and the pilot conductor carry separate specifications in AS/NZS 2802:2000 Table 18, unlike Type 450 where a single combined entry covers all three interstitial positions.

Pilot conductor overload in high-signal-current applications: Type 451 uses a reduced pilot — verify pilot current requirements against conductor CSA before specifying. Where higher pilot current capacity is needed, use Type 450.

Screen fatigue in long trailing cycles: Composite braid screen (tinned Cu wire interwoven with PET yarn) with ≥80%coverage per AS/NZS 2802 Cl. 12.4.4 maintains earth fault detection integrity throughout service life.

Sheath wear at drum flanges: Mandatory PET yarn reinforcement within the XHD sheath (Cl. 23.1.2) provides mechanical protection at high-stress contact points

Flame retardant and self-extinguishing per AS/NZS 2802. XHD-85-PCP or XHD-90-CSP/CPE extra heavy-duty sheath provides superior ignition resistance and flame propagation performance over Class 2 cables.

† Sizes beyond AS/NZS 2802:2000 Table 18 manufactured to Znergy Engineering specification — confirm dimensions prior to ordering.

Type 451 is the reduced-pilot variant of Type 450 — same power core and sheath construction, smaller pilot conductor. Choose Type 450 where a full-size interstitial pilot is needed. Choose Type 455 where semiconductive (not composite) screening is preferred at 3.3–11 kV. Choose Type 441 (Class 1) where individually screened power cores are required at 3.3–22 kV.

Standard AS/NZS 2802:2000 — Class 1 (Table 18)

Configuration: 3C + 2E interstitial + 1 reduced pilot interstitial

Centre: Plain elastomer centre filler (no cradle separator)

Conductor: Tinned annealed Cu, rope-lay (Class 5 flex) per AS/NZS 1125

Conductor Screen: Extruded semiconductive elastomer per core (Class 1)

Insulation: XR-EP-90 (Class 1 high-grade EPR) per AS/NZS 3808

Insulation Screen: SC elastomer + composite braid per core; bonded at 6.6 kV+

SC tape: Semiconductive tape over composite screen per core

Earth conductors: 2 × interstitial, tinned Cu, elastomer covered

Pilot conductor: 1 × interstitial, tinned Cu, elastomer covered —reduced CSA

Interstitial fillers: Remaining outer interstice space filled by outer sheath directly

Core assembly tape: Textile tape where separate fillers are used (optional)

Outer sheath: XHD-85-PCP or XHD-90-CSP/CPE — reinforced with PET yarn (mandatory) per AS/NZS 2802 Cl. 23.1.2

ZNE[size]-451.[voltage]
e.g. ZNE95-451.11 = 95 mm2 Type 451 at 11/11 kV (Class 1)

• Open cut rope shovels and draglines at 11–33 kV — low pilot-current protection schemes
• Surface mine trailing supply where pilot monitoring only (not load) is required
• Open pit portable substations at 22–33 kV with pilot relay protection
• High-voltage trailing connections where reduced pilot CSA is acceptable
• Cost-optimised alternative to Type 450 for signal-only pilot circuits
• Surface plant primary supply at 33 kV with minimal pilot current demands