Whether it is a small garden shed, a farm workshop or a large machinery shed, getting electricity to a separate building is one of those jobs that is much easier when it is planned properly from the beginning.
Start with what the shed will actually be used for
The first question is not how big the shed is. It is what you plan to run in it. A couple of lights and a power point are very different from a workshop with welders, compressors, pumps, machinery or an EV charger.
It is worth thinking about future use as well. Installing a supply that only just meets today's requirements can become false economy if another circuit, larger machine or EV charger is added later.
How is power normally run to a detached shed?
For a detached shed, the usual approach is to install a dedicated electrical supply from the main installation to a switchboard in the shed. From there, the shed can have its own lighting, power and equipment circuits as required.
On rural properties this often means an underground cable between the house or main switchboard and the shed. The exact cable, protection and installation method depend on the electrical load, distance and conditions on the property.
Distance matters
A shed that is ten metres from the house is a different job from a workshop a hundred metres away. As cable length increases, voltage drop becomes an important part of the design.
Simply choosing a cable because it can carry the expected current is not enough. The cable also needs to be sized so equipment at the far end receives an appropriate voltage when it is operating.
What about the trench?
Underground electrical supplies need to be installed at appropriate depths and with the required mechanical protection and identification. The route also needs to take account of other services, vehicle traffic and what might happen on the property in the future.
For rural jobs, trenching is often a significant part of the work. SECS has access to excavation equipment and an experienced operator, so the electrical work and the practical job of getting the cable across the property can be considered together.
Single phase or three phase?
Many sheds are perfectly well served by a single phase supply. A workshop with larger machinery, significant heating loads, larger pumps or other three phase equipment may justify a three phase supply where it is available.
There is no benefit in installing three phase simply because it sounds better. The sensible approach is to look at the equipment, likely future loads, existing property supply and cable run before deciding.
Plan before the shed is finished
If you are building a new shed, talk to an electrician before the slab, driveway, landscaping or internal fit-out makes the cable route difficult.
A little planning can also allow for future data, control wiring, pumps, gates, cameras or other services that may eventually need to reach the same part of the property.
In Short
There is no single correct shed supply for every property. The right solution depends on how far away the shed is, what you intend to run, what electrical supply is already available and what you might want to add later. Designing it around the actual property usually produces a much better result than simply running the smallest cable that will do today's job.