Sub-Mains Installation
Sub-mains installation sized to AS/NZS 3008 for new residential and commercial premises across Sydney
Sub-Mains Sized Right from the Start
Sub-mains installation involves installing the cables that run from the point of supply — the network connection point, meter, or main switchboard — to sub-distribution boards or tenant switchboards within a building. Sub-mains are distinct from consumer mains (which connect the network to the main switchboard) and are common in multi-tenancy buildings, strata complexes, commercial fitouts, and new residential premises with secondary structures. Correct sizing to AS/NZS 3008 based on calculated maximum demand is critical — undersized sub-mains create safety hazards and require costly replacement when demand grows.
Sub-mains installation is a core part of new premises connections across Sydney's development pipeline. New strata developments in Parramatta, Macquarie Park, and the North Shore require sub-mains from the main switchboard to individual lot metering points. New commercial fitouts in the CBD and suburban centres need sub-mains from the landlord's switchboard to tenancy boards. Dual occupancy projects in established suburbs require correctly sized sub-mains to the secondary dwelling. We calculate maximum demand, specify the correct cable size, and install sub-mains as part of the complete new connection process.
Sub-Mains Installation Process
Maximum Demand Calculation
Calculate the maximum demand for the sub-mains run to AS/NZS 3008, factoring in all connected and planned loads.
Cable Specification
Select the correct cable size, installation method, and route based on demand calculations and AS/NZS 3008 de-rating factors.
Route Preparation
Prepare the cable route including conduit, cable tray, or direct burial as appropriate for the installation type.
Sub-Mains Installation
Pull and terminate cables from source switchboard to sub-distribution board or metering point, correctly identified and labelled.
Testing & Certification
Test sub-mains for continuity, insulation resistance, and polarity, and issue certificate of compliance.
Maximum Demand Calculation
Calculate the maximum demand for the sub-mains run to AS/NZS 3008, factoring in all connected and planned loads.
Cable Specification
Select the correct cable size, installation method, and route based on demand calculations and AS/NZS 3008 de-rating factors.
Route Preparation
Prepare the cable route including conduit, cable tray, or direct burial as appropriate for the installation type.
Sub-Mains Installation
Pull and terminate cables from source switchboard to sub-distribution board or metering point, correctly identified and labelled.
Testing & Certification
Test sub-mains for continuity, insulation resistance, and polarity, and issue certificate of compliance.
Fully Accredited & Compliant
Licensed, accredited, and compliant with all NSW electrical and network requirements
Level 2 ASP — Class 2A & 2D Accreditation (NSW Fair Trading)
Current ASP Class 2A and 2D accreditation registered with NSW Fair Trading, authorising sub-mains installation as part of new connection works.
Ausgrid Accredited Service Provider
Authorised for new premises connection works across the Ausgrid network area covering Greater Sydney eastern and northern suburbs.
Endeavour Energy Accredited Service Provider
Accredited for new connection and sub-mains works across Western Sydney, Hills District, and Sutherland Shire network areas.
AS/NZS 3008 Cable Sizing Compliant
All sub-mains sized to calculated maximum demand using AS/NZS 3008 cable current-carrying capacity and de-rating requirements.
AS/NZS 3000 Wiring Rules Compliant
Sub-mains installation, termination, and protection completed to the Wiring Rules with certificate of compliance issued.
Work Health & Safety Act NSW Compliant
All sub-mains installation completed under documented SWMS, isolation procedures, and WHS requirements for construction site work.
When Do You Need Sub-Mains Installation?
New strata development requiring sub-mains to individual lot metering points
Strata buildings require sub-mains from the main switchboard to each lot's metering enclosure — correctly sized for individual maximum demand.
Commercial fitout requiring sub-mains from landlord's switchboard to tenancy distribution board
New commercial tenancies need dedicated sub-mains from the building's main or landlord switchboard to the tenancy distribution board.
Dual occupancy requiring sub-mains to secondary dwelling switchboard
Secondary dwellings on the same lot require correctly sized sub-mains from the main switchboard to the secondary dwelling's board.
New residential build with secondary structure requiring sub-mains feed
Granny flats, workshops, and detached studios require sub-mains from the main switchboard sized to the structure's calculated maximum demand.
Building upgrade where existing sub-mains are undersized for current maximum demand
Renovations and fitouts adding high-demand loads may require sub-mains replacement when existing cables cannot carry the updated maximum demand to AS/NZS 3008.
Why Choose Sedgman for Sub-Mains Installation?
Correctly Sized Every Time
We calculate maximum demand to AS/NZS 3008 before specifying cable size — no undersizing that creates safety issues or requires replacement when demand grows.
Part of the Full Connection
Sub-mains installation is coordinated with DNSP application, consumer mains, and metering as part of a complete new connection — one contractor, no gaps.
All Premises Types
Residential, strata, commercial, and industrial sub-mains installed and certified across Greater Sydney.
Other New Premises Services We Offer
Frequently asked questions
Straight answers about sub-mains installation in Sydney.
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Contact Sedgman Electrics for sub-mains installation across Sydney.
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