400A Electrical Supply Specialists Sydney
As Sydney's dedicated 400A Level 2 ASP specialists, we coordinate Ausgrid, Endeavour Energy and Essential Energy approvals, Level 3 network design, Level 1 construction, and Level 2 installation under one roof. One contractor. One point of contact. Fixed-price quotes.
Is a 400A Supply Right for Your Site?
A 400A supply is required when your electrical demand exceeds what a standard 200A service can deliver. These are high-load environments where power reliability isn't optional — it's operational.
Contact US- Large commercial tenancies and retail centres
- EV fleet charging depots
- Development sites transitioning from Temporary Builder's Supply to permanent high-capacity connection
- Industrial warehouses and manufacturing facilities
- Cold storage and refrigeration-heavy operations
- Large hospitality venues and commercial kitchens
- Large strata complexes with significant common area demand
400 Amp Three-Phase Power for Heavy-Demand Sites
A 400A electrical supply delivers up to 400 amps of three-phase power to a single site — roughly double the capacity of a standard 200A commercial connection. In NSW, supplies above 200A are not off-the-shelf installations. They require network distributor pre-approval, certified maximum demand calculations, correctly sized service and consumer mains, a commercial-grade main switchboard, and (where the network can't accommodate the load) Level 3 design and Level 1 construction works.
High Demand Electrical is one of the few Sydney Level 2 ASP contractors that delivers the full 400A supply pathway in-house — from the network application through to the final CCEW. We don't subcontract the technical work to a third party. Maximum demand calculations are prepared by us. Network applications are submitted by us. Installation is performed by our own Level 2 ASP team. Where Level 3 design or Level 1 construction is required, we coordinate it under HDE — you never have to chase another contractor.
What We Install — The Complete 400A Underground System
We handle everything from the network connection point to your switchboard. No partial scopes. No handoffs to other contractors.
400A Service Mains
400A Consumer Mains
400A Earthing System
400A Main Switchboard
Private Pole (Where Required)
Smart Meter & CT Metering
Our Energy Providers
Authorised by Sydney's major networks
All Three Networks — Ausgrid, Endeavour Energy & Essential Energy
400A supplies require network pre-approval and are subject to maximum demand assessment by the distributor. We manage the entire approval process across all three NSW networks — so you never have to deal with Ausgrid, Endeavour Energy or Essential Energy directly.
Maximum demand calculation prepared in-house by HDE
Network application submitted to Ausgrid, Endeavour Energy or Essential Energy
Network capacity assessment coordinated and tracked
Level 3 design managed through our accredited partners where network construction is required
Level 1 ASP construction coordinated through our network of accredited subcontractors
NOSW lodgement and CCEW issued on completion
The Process — From Application to Energisation
From maximum demand calculation through to energisation — here’s exactly how High Demand Electrical manages a 200A underground upgrade end to end.
- Maximum Demand Calculation
We prepare a certified maximum demand assessment for your site. This is the technical foundation of your application — determining whether 400A is the right solution, and ensuring your application is accurate and approvable first time. - Network Application
We prepare and submit your supply upgrade application to your network distributor — Ausgrid, Endeavour Energy, or Essential Energy — on your behalf. The application includes your maximum demand calculation, site details, and proposed supply configuration. We handle all the paperwork. - Network Assessment
The distributor determines whether existing network infrastructure can support a 400A supply at your location. There are two possible outcomes: if capacity is available, we proceed directly to installation. If not, network construction is required — this is where most contractors hit a wall. We don't. - Level 1 / Level 3 Coordination (If Required)
Where the existing network can't support the upgrade, we coordinate a Level 3 network design through our managed design partners, and Level 1 ASP construction through our established network of accredited subcontractors — all managed under HDE. - Level 2 Installation
Our Level 2 ASP team installs the complete 400A system at your property — service mains, consumer mains, earthing, switchboard, private pole (where required), metering upgrade, and all compliance works. NOSW lodged and CCEW issued on completion. - Energisation
Your 400A supply is energised, tested, commissioned, and signed off. All compliance documentation issued.
Why Choose High Demand Electrical?
Experience, accreditation and a fixed-price approach that removes uncertainty from complex Level 2 underground projects.
Level 2 ASP Licensed
All Three Networks
In-House Max Demand
Full Supply Chain
Fixed-Price Quotes
300+ Five-Star Reviews
Triple ISO Certified
24/7 Response
Complementary Level 2 ASP Services
Power Supply Upgrades
Consumer Mains Installation
Switchboard Upgrades
Overhead Service Mains
Underground Service Mains
Private Power Pole
Smart Meter Upgrades
Level 3 ASP Design
Level 1 ASP Construction
Power Logging
Temporary Builder Supply
EV Charger Installation
Get Your 400A Underground Upgrade Quote Today
High Demand Electrical - 400A Underground Upgrades
FAQs
Answers to the questions we hear most from Sydney homeowners, builders, and site managers.
A 400A electrical supply delivers up to 400 amps of three-phase power to a site — roughly double the capacity of a standard 200A commercial service. It's required when load calculations exceed what a single 200A connection can deliver — typically large commercial tenancies, industrial facilities, EV fleet depots, cold storage, hospitality venues, and large strata complexes.
A standard upgraded supply in NSW is 200A three-phase. Where demand exceeds what a single 200A service can deliver, a 400A supply is achieved — typically via parallel consumer mains runs or a higher-rated network connection. We assess your load and recommend the right solution.
Not always — it depends on the available capacity in the local network at your site. We submit the application and the distributor advises. Where construction is needed, we manage Level 3 design and Level 1 ASP construction under HDE.
Timeline depends on network approval and whether construction is required. A straightforward 400A installation can be completed in a day once approved. Network applications typically take several weeks to assess — we'll give you a realistic timeline at the quoting stage.
Costs vary based on whether network construction is required, the length of service mains, switchboard sizing, and metering. Straightforward 400A installations on existing capacity start lower; projects requiring Level 3 design and Level 1 construction cost more. We provide a fixed-price quote after the site assessment — no hourly rates, no surprises.
Testimonials
"Chris was the professional, punctual and his services are exceptional. Chris re-wired the entire property, chased the electrical work in the bathroom and kitchen areas, left a clean and tidy environment and his open communication and dialogue was a welcomed experience.
When he quoted an arrival time, he was there. He talked me through what he was doing, and provided feedback/suggestions on how to tackle any issues. I felt part of the process, as opposed to being another Customer.
A pleasure to deal with, and I recommend his services. I'll be definitely calling him again with any electrical work I need done."
"Chris and his team are a professional outfit who were friendly and very helpful with any questions I had about the work they were doing. They completed their work promptly and to a high standard of quality. Would definitely use them again for any future electrical works!"
"HDE did a great job at our place, Chris was highly responsive, professional and a master of his craft; there was no challenge too great. I would highly recommend High Demand Electrical."
"Chris and his team did a great job. Excellent customer service all round. Great communication, very thorough and professional. Took the time to get the job done right and cleaned up afterwards Would hire again and definitely recommend. A+ job."
"Great electricians- very professional and efficient with doing the electricals for our kitchen renovations & new lighting in our apartment. Gave good suggestions as well for kitchen cupboard lighting. Highly recommend them."
Our Partners
Powering Your Needs with Expertise
If you’re looking for a reliable, experienced, and prompt electrician, look no further than High Demand Electrical. We cater to all your electrical needs, from routine maintenance to emergency repairs and complete system installations. Our skilled team is committed to providing professional service that ensures your electrical systems run smoothly. Whether it's a small task or a large project, give us a call today. Let us meet all your electrical demands with the quality and reliability you deserve.
