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The Differences Between High And Low-Voltage Garden Electric Circuits

by Riley Howes (2018-11-14)


Low-voltage garden electric circuits

Much of the electric wiring you will have in or around your pond is likely to be Low Voltage Cabling-voltage. That is, run at a safe 12 or 24 volts from a transformer. Only the transformer needs be connected to mains electricity; the low-voltage cable, which runs to the pond lights or to a low-voltage pond pump, can then be run along the surface of the ground without posing any danger. Legislation, and therefore manufacturers, err on the side of safety, and in many countries now electrical items such as pond lights have to be low-voltage: mains-voltage versions are no longer permitted. Some transformers are designed to be used if outside and, if waterproof, even in the pond itself; if not, they must be used either inside the house or in a garden shed or other outbuilding with the low-voltage cable run outside. The problem that arises with a low-voltage circuit is how to run the cable from the house or other outbuilding and into the pond. The simplest way to get it out of the house, is to drill a hole in a convenient window frame, pass the cable through and then seal the hole with a matching silicone sealant or building mastic. To get it into the pond, you can simply pass it in behind some of the surrounding stones, or buy the special watertight cable lead-outs which some manufacturers make specifically for passing cable through walls.

Mains-voltage garden circuits

Serious pond owners will want to have a permanent outside electric circuit. Unless you are extremely competent, this should always be installed by a professional electrician. Such a circuit should have its cable buried in the ground deep enough to avoid being severed by digging with a spade, i.e. at least two spits deep. It is possible to use normal house wiring cable for this, but it must be protected by a rigid PVC conduit; the alternative is proper armoured cable, available through DIY stores and electrical retailers, which requires special fittings for the termination at either end. External sockets (also available through electrical wholesalers) have their own special plugs - each socket comes with a plug and extra plugs are available.

The alternative to a plug and socket, for permanent wiring, is a junction box with up to six outlets. These are widely available from water garden suppliers and can either be switched or unswitched (a separate switch serves each outlet).

Joining cable

If for any reason you need to join mains electric cable in the garden, you must make sure that you have the right type of connector, i.e. weatherproof or waterproof. The non-weatherproof kind is only suitable for use indoors and should not be considered for anything to do with the garden. You pay more for the weatherproof kind which can be used outside and even more for the watertight versions, some of which are suitable for immersion in a pond. Check the packaging and instructions carefully to make sure you get the type you require: all water garden centres should have suitable connectors as all the major suppliers have connectors in their range.