One of the first decisions on any ASP Level 2 job is whether the connection runs overhead or underground. Each has trade-offs in cost, installation time, compliance requirements, and what the DNSP will accept.

Overhead Connections (ABC)

Aerial Bundled Cable (ABC) is the traditional approach for most residential service connections in Australia. It's faster to install, cheaper on materials, and doesn't require trenching.

Typical cable: 16mm² or 25mm² ABC
Cost advantage: No trenching, no conduit, no backfill — significantly cheaper labour
Span limits: Most DNSPs limit spans to 30-40m between poles without intermediate support
Clearances: Must maintain minimum ground clearance (3.7m residential, 5.5m over driveways)

Underground Connections (XLPE)

Cross-linked polyethylene (XLPE) cable in conduit is increasingly common, especially in new estates and areas where overhead isn't permitted or practical.

Typical cable: 16mm² to 50mm² Cu or Al XLPE
Higher materials cost: Conduit, cable, inspection pits, pit lids, warning tape
Trenching required: Minimum 500mm depth (600mm under driveways), plus restoration
Inspection pits: Required every 50m and at every change of direction per Service & Installation Rules

When to Use Each

Overhead wins when there's existing pole infrastructure, short spans, and no aesthetic objections. It's the cheaper option for most standard residential connections.

Underground wins when the client wants clean aesthetics, the DNSP requires underground in new estates, the property has no pole access, or the overhead span would exceed limits.

Many jobs use both — an underground run from the property boundary to the building with an overhead span from the network pole. MAINS lets you draw mixed overhead and underground segments and calculates materials for each independently.