Point of Attachment and Service Fuse Explained for Homeowners (No Textbook Jargon)

What do "point of attachment" and "service fuse" actually mean on your electrical quote? These are two of the most common terms Sydney homeowners see and never get a plain explanation for. The point of attachment is where the network's overhead line connects to your property, and the service fuse is the protection device that sits between that connection and your meter. Both are governed by the Service and Installation Rules of NSW (SIRNSW), and both matter more than most people realise.

This guide explains what each term means, why they come up during quotes for supply upgrades, and what SIRNSW actually requires of them.

If your quote includes replacing the cable from the point of attachment to your switchboard, that is a consumer mains upgrade.

1. What is the point of attachment on an overhead service?

The point of attachment is the exact location on your building where the network's overhead service cable terminates and connects to your consumer mains. SIRNSW requires this point to sit between 3 metres and 6.7 metres above ground, and it must face the side of the street where the overhead lines run.

This is not an arbitrary number. It accounts for cable sag, ground clearance for vehicles and pedestrians, and safe access for network crews. A point of attachment that is too low, too high, or facing the wrong direction usually means the original installation predates current rules, or the property has since been renovated in a way that changes the geometry.

2. Why the point of attachment matters during upgrades

Any time you increase the size of your supply, whether that is a single phase to three phase upgrade or a straightforward power supply upgrade, your point of attachment gets reassessed. If it no longer meets height, clearance or access requirements, it has to move as part of the job.

This is one reason two seemingly similar upgrade quotes can differ. A property with a compliant point of attachment in the right spot is a simpler job than one where the attachment point needs to be relocated, which may also require a private power pole if there is nowhere suitable on the building itself.

3. Service fuse: your protection at the point of supply

The service fuse sits between the point of attachment (or underground service) and your meter, and its job is to protect the incoming service cable. SIRNSW requires this device to be rated at least 100 amps, fitted with a sealable, tamper resistant escutcheon so it cannot be accessed without authorisation.

For a single domestic property, one 80 amp device can do double duty as both the service fuse and the meter fuse, provided it is located and rated correctly. Larger services need dedicated HRC fuse gear with higher breaking capacity and phase segregation.

4. Why old rewireable fuses always get replaced

If your property still has an old ceramic rewireable fuse acting as the service protection device, SIRNSW requires it to be replaced with a modern, compliant device the moment any work touches it. This is not optional and applies even if the rest of the job is unrelated, such as a smart meter upgrade or defect notice rectification.

In practice, this means older Sydney homes with original fuse gear often get a service fuse upgrade bundled into whatever other electrical work is happening at the switchboard.

Who can repair a point of attachment or service fuse?

The point of attachment and service fuse both sit at, or upstream of, the network's point of supply, which puts them squarely in Level 2 territory. A Level 2 electrician is accredited to work on this side of the meter, coordinate with the network, and relocate or replace fittings that a standard electrician is not authorised to touch.

How High Demand Electrical helps

When we quote a power supply upgrade, we check your point of attachment and service fuse as standard, so there are no surprises once work starts. If either needs relocating, upgrading, or replacing, we handle the network side of the process along with the physical work.

Not sure where your point of attachment or service fuse stands? Get a power supply upgrade quote from High Demand Electrical, or call 0402 559 777. Every job needs a site assessment before scope and pricing are confirmed.

Related reading: What Are the Access and Height Rules for Your Point of Attachment in Sydney?