What size of transformer do I need to power a group of garden lights?
A. This is simply a matter of multiplying the wattage and numbers of the lamps (bulbs) used in the garden light fittings (or luminaire as they are called in the professional lighting trade) to be connected to the transformer. In most cases we need to consider some spare capacity within the transformer rating so that we have scope to increase some lamp wattages as plants grow, or to allow for some flexibility in adding an extra spotlight or other garden light in future. This helps the garden lighting to grow with the garden. See Help sheet No.
