Installation of any electrical equipment in a garden, including outdoor lighting, is a job for qualified electrical contractors, especially if water is involved, but understanding some of the issues which need to be considered will help when drawing up an installation brief for your contractor that reflects your requirements. It may also help the installation to run more smoothly, and the finished scheme will certainly be more successful if you appreciate how the various parts of the project relate to one another.
Safety
Installing electricity in the garden is not a job for amateurs, and it can be lethal if incorrectly installed or if inadequate provisions have been made in the event of an equipment fault. Water is a main threat, seeping through joints and gaskets and it can be drawn into electrical enclosures by capillary action, forming from repeated condensation cycles and penetrating ageing materials which corrode, crack or are damaged by wildlife, pets, children, careless gardening or wear and tear. Correct circuit protection for all exterior electrical services should include a residual current device (RCD). This ensures the power is cut off immediately when it detects a leakage of current to earth, which indicates an electrical fault potentially threatening to life.
Who does what?
Whilst an electrical contractor is qualified to install your lighting system, they won’t necessarily have the required experience designing such systems. You may already have decided to seek the services of a garden lighting specialist who will help plan and prepare the lighting design you require. When making your choice, look for evidence of experience in testimonials, recommendations, or photographs of completed projects.
Power for the system
Outdoor lighting is rarely installed as the only equipment run by electricity in a garden, and these other services must be considered. This doesn't mean the power for all equipment must come from the same place. Lighting is slightly different because convenience usually demands the switches are in the house or on the patio. Most other services, such as supplies to exterior electrical sockets, sheds and irrigation controllers, are either unswitched, or like timers to control fountain pumps, may need to be turned off at night.
Power for simple systems
Many systems need only a limited amount of power. A small system with a few spotlights for an ornamental effect, an additional path or patio lighting circuit and a low-power pump for a feature will consume less than 5 amps of power. These can usually be wired as a spur from an electrical socket, via an RCD, a small switch panel and junction box to connect the exterior cables.
Power for larger systems
When lighting is provided for a large property, the total exterior electrical load can be both high and complex. This can include lighting, water pumps and irrigation systems, as well as electrical supplies for pools, outbuildings, and electric gates. The amount of power required usually dictates the electrical source for exterior circuits should come from the main electrical supply, preferably via a separate distribution board. This will contain residual current devices (RCDs) to provide essential safety protection and miniature circuit breakers to provide protection against overload and short-circuiting.
Laying Cables
Providing cables for complex electrical systems in larger gardens should be done by an electrician. The amount of mains-voltage cable required for garden lighting will be reduced if a low-voltage system is chosen. Flexible low-voltage cables can be run from transformers that are hidden behind plants and landscape features so that all that is needed is relatively simple infrastructure of mains cabling to the transformers. Mains-voltage cables must be buried so deeply that they are unlikely to be disturbed by subsequent gardening. You’re looking at 30-45cm below a lawn and 45-60cm below cultivated ground. Using a mains-voltage cable layout will reduce the amount of digging required, which can be an important factor in an established garden and digging a trench around the edge of a lawn is generally easier than through mature, well-grown borders.
This has been a brief rundown of what you need to consider when implementing and installing a lighting system in your garden. If you require more information, please don't hesitate to contact us and speak with our experienced team.