Garden Lighting Frequently Asked Questions

Below are just a few of the most garden lighting Frequently Asked Questions on the wide range of products & services offered by All Weather Lighting.

Click on any of the garden lighting related questions below to read the answer. If you have any other questions regarding any of our garden lighting products or services please do not hesitate to contact us.

  1. How many lights can I power from one transformer?
  2. What is a transformer and why do I need one?
  3. Can the transformer be mounted outside?
  4. How far can I run a low voltage cable from a transformer to a garden lighting product?
  5. How many low voltage garden lighting products can I connect to one cable?
  6. Do lights get hot?
  7. Can I install any garden lighting products myself?
  8. How do I know what lamp beam to buy?
  9. How can I fit recessed lights in decking?
  10. Do copper lights go green after a short while?

Q1. How many lights can I power from one transformer?

A. In fact, transformers are available in a wide range of wattage ratings, so we need to look at the question the other way around: "what size of transformer do I need to power the group of lights required"? This is simply a matter of multiplying the wattage and numbers of the lamps used in the luminaires (garden lighting fittings) to be connected to the transformer.

For example 6 light fittings at 20 watts = 120 watts in total. Therefore a 150 watt(va) transformer is required.
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 a luminaire in the future. Make sure the transformer is at least 60% loaded - don't wire one low power light to a big transformer in the expectation of installing lots of other lights later - all you will do is over-volt the small lamp and shorten the bulbs life !

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Q2. What is a transformer and why do I need one?

A. Most good garden lighting works at 12 volts, so you need to locate transformers in the garden or nearest building and use flexible low voltage cable from the transformer to the lights themselves. A transformer is an electrical or electronic device which changes voltage from one level to another; in lighting this is usually from 240 volts to 12 volts, which is the voltage at which many garden lighting products work. From the transformer to the luminaries (light fittings), the low voltage cable typically runs under mulch and over garden structures.

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Q3. Can the transformer be mounted outside?

A. Yes. The standard range of exterior garden lighting transformers are housed in black weatherproof IP rated boxes, normally to be mounted on a wall or post where they will be hidden behind planting and landscape features, or in manholes, under decking, and in outbuildings. Special ground burial types are available for locations where it would be difficult to site a transformer within a reasonable distance of the garden lighting fitting.

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Q4. How far can I run a low voltage cable from a transformer to a garden lighting product?

A. Cable loses voltage according to its length and the number & power of lights you connect to it, so keep low voltage cable runs as short as possible to optimise the performance of your garden lighting products. To minimise cable voltage drop to the luminaires, identify groups of lights which can be supplied from one central transformer.

Check that the transformer location is within the length of the low voltage cable permitted (see voltage drop chart: In many rear gardens, a typical configuration may require one transformer on each side of the garden and perhaps one transformer to cover features at the far end of the garden. The 240 volt supply to the transformers should be via a steel wire armoured cable incorporating a separate core for earthing.

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Q5. How many low voltage garden lighting products can I connect to one cable?

A. Adding too many lights onto one cable increases cable voltage drop and reduces the distance the cable can be run before the loss of voltage dims the garden lighting products too much. See the question above for the solution to this.

As a rule of thumb, wire a maximum of three 20 watt lights equally spaced along a 10 metre ground burial cable and wire higher power lights individually from the transformer position to allow flexibility in positioning the garden lighting fitting in the future as planting grows or the garden changes.

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Q6. Do lights get hot?

A. Yes, but some get hotter than others. For example, recessed garden lighting products in decking and paving will get particularly hot with a 50 watt lamp fitted, so don't use these in unshielded areas where people or pets might stand on them; if in doubt use a recessed light with a protective grid over the lens or stick to 20 watt lamps for a cooler lens temperature. Likewise, spotlights with 50watt lamps and upwards get particularly hot when they've been on for a little while; you should wear a good pair of insulating gloves (such as thick gardening gloves) to protect your hands when adjusting spotlights.

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Q7. Can I install any garden lighting products myself?

A. Low voltage garden lighting products are easy enough to connect but the transformer connection and installation of any other mains voltage lights or equipment can lead to dangerous situations if not done correctly. The equipment we supply is used by professionals to create lighting effects beyond the capabilities of most DIY equipment. You should employ a qualified electrician to undertake any exterior electrical installation, or to test an existing system.

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Q8. How do I know what lamp beam to buy?

A. The principal beam angles for low voltage reflector lamps are 12, 24, 36 and 60 degrees. Sometimes you will want a small pool of light from a narrow beam to accent a feature without lighting the surroundings; other subjects will require the widest coverage available, such as a 60 degree beam. For example, a 60 degree beam will provide wide coverage from a pergola beam only 1.5 metres above a table below, but if you are uplighting a slender tree the coverage of a 600 beam will be wasted in the night sky; a narrower beam ,10 degree, will "fit" the shape of the tree more closely. If in doubt, be prepared to experiment a bit by changing the lamp to compare the different garden lighting effects.

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Q9. How can I fit recessed lights in decking?

A. There are several types of garden lighting products which can be used;
One of the most popular is the Hunza copper path light PTL; it eventually weathers to a soft verdidris colour which tones well with the natural colour of wood and stone.

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Q10. Do copper lights go green after a short while?

A. No. It usually takes a long time for copper garden lighting products to acquire a verdigris patina. This is a chemical process which takes time unless the copper is subjected to chemical catalysts such as polluted water or garden sprays. Copper lights will usually acquire a natural-looking mottled brown finish after just a few weeks outside. If you want the verdigris finish, spray two or three times a week with a copper fungicide such as Benlate to hasten the process. If your copper lights turn green and you prefer the natural brown weathered appearance, clean them with bathroom limescale remover and let them weather again naturally.

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