12v & 240V Outdoor Lighting Installation – FAQs

Lumena offer a wide range of 12v and 240v garden lights. Below you will find a list of FAQs, with answers explaining all you need to know to ensure your outdoor lighting system is wired correctly. These include: general information on low voltage garden lighting, 240v lighting, installation and also about us as a Company.


Is 12v lighting safe to use?

12 volt systems are intrinsically safe and will not give an electric shock if wrongly wired, short circuited or damaged. Lumena highly recommend the use of low voltage lights wherever possible.

The size of the transformer you require is determined by the total wattage of light fittings that you are powering. The size of the transformer is basically the “maximum wattage”.

For example: 3 lighting fittings each using a 5W lamp totals 15W (3 x 5=15). The transformer required to power these 3 fittings together needs to exceed this wattage to ensure that it is not overloaded. In this case, the 20W transformer would be required, leaving 5W spare capacity. It is always recommended that there is some spare capacity left in the transformer to allow for power surges or slight differences in lamp wattage.

It is equally important that Transformers are not be under loaded or the output voltage may rise, which could result in the lamps being powered coming to the end of their life slightly earlier than expected. For optimum performance, transformers should be loaded to 50-80% of their capacity; for example a 20 watt transformer should power lights between 10 & 15W. Although this our recommendation, it is possible to power slightly less or more, as long as the transformer is not overloaded.

Mains 220-240v AC systems:  Essential! All additional permanent wiring, with the exception of very minor work, must be notified to the local Council building control department, or an electrician who is registered with one of the Government-approved “Part P” schemes must carry out the work. This electrician will then take care of all of the necessary procedures and will provide you with a certificate that confirms the work meets Building Regulations / BS 7671. It is best to find an electrician who is experienced in outdoor installations as they can be more complex than indoor and involve armour plated cable which is more complex to work with than normal household wiring cable. If installation is carried out by somebody who is not a registered competent person, the use of registered third party to certify notifiable electrical installation work is acceptable as an alternative to using a building control body for the entire installation.

Some minor work outdoors, such as replacing an outdoor light which is already connected to an existing circuit, is not currently notifiable (June 2016). Local Council will always be happy to advise whether or not specific work is notifiable so do check if in doubt!

12v AC systems: Recommended to use a qualified electrician but if the lights are not permanently / directly hard wired into the house wiring circuits then it is permissible for a DIY installation. To qualify for a temporary installation, the transformers must be able to be unplugged from the external waterproof sockets, or an indoor socket such as in a garage or shed. Any mains outdoor waterproof sockets must be installed by a qualified electrician.

Mains 220-240v AC systems:  Recall your electrician to check it out and replace any damaged cable.Mains cable located in the garden should either be armoured or laid within armoured conduit. Guidelines also recommend that armoured cable is buried at least 0.5m below ground to avoid damage.

12v AC systems: If it is 12v Rubber cable which has been damaged, that particular section can be cut out and replaced with new outdoor rubber cable relevant to your specific circuit (usually 0.75mm or 1.5mm). Use IP65 rated cable connectors (or higher) to join the new cable to the existing circuit.


Unfortunately, the answer is yes, but it is rare if the cable is buried or if it is mains armoured cable as the metal surround is designed to protect the inner cables in situations such as this. To prevent damage to low voltage cable from animals and protect the cables further, the use of “Blue” heavy duty plastic water pipe to surround the cable or other suitable outdoor cable protectors is recommended.

All Lumena 12v garden lights must be wired into a transformer. The transformer can then be plugged directly into the mains, or hard wired if the 3 pin UK plug is removed. This then converts the input mains voltage (220-240v) to an output of 12 volts. If a transformer is not used, the circuit will not be safe and the lights / sensors will blow.

Use a waterproof junction box. The use of heavy duty “choc block” connectors inside will make it easy. If there are too many wires to fit inside each terminal / connector then more than one can be connected to one another using some solid insulated wire, like a “daisy chain”. Lumena lights stock Eazylink 4 way and 8 way junction boxes which really are extremely simple and time saving to use, as well as standard WISKA Boxes.

Also, some Plug and Play systems have easy plug in connectors for easy connection. Some branded plug & play systems may be limited and restrict the type and make of lights that can be used. Lumena’s VERSA Plug & Play Range is extremely versatile, using adaptors which are also compatible with other systems.

No. It is very important that 12v lights are wired in parallel, which means all the same coloured wires should be connected together using a junction box, and not run from one fitting to another. Wiring in series will result in significant voltage drop and there will not be enough power in the circuit to illuminate the lights. It also means that if there is an issue within the circuit, any fitting located after the fault would also cease to work. This could be something as simple as bulb failure.

Easy to follow 12v wiring instructions can be viewed, downloaded and printed, detailing how to wire your 12v lighting system in parallel using a “Wiska” Junction Box. Click HERE.

Lumena recommend and supply 2 core insulated rubber cable. For most applications 0.75mm² cable is sufficient, but for longer runs of over 20m, we recommend the use of 1.5mm² cable to reduce any voltage drop. In places of possible cable damage by rodents etc., we advise placing the cable inside flexible conduit for added protection.

Yes. There a couple of ways to do this, depending on where the sensor is to be located. If positioned after the transformer, within the 12v wiring circuit, then a 12v sensor must be used. Lumena offer a range of outdoor photocell and PIR sensors in 12v. If located before the transformer, so within the mains power supply, a 220-240v sensor can be used, again available from Lumena. Wherever the sensor is positioned within the circuit, any subsequent fittings will be controlled by the sensor. Therefore, different areas in the garden can be connected to different sensors, e.g. motion sensors, so that a specific group of lights are triggered by one sensor, and another group / area by another sensor.


For UK Mainland, delivery is free of charge for orders over £200 + VAT (£240 inc VAT). Orders under this amount will be charged at £10.00 + VAT (£12.00 inc VAT).

For non-UK Mainland, additional charges will apply. Courier charges are passed on at cost. Please call us for a quote if you are not based in UK Mainland.

Exports – we are happy to export orders outside the UK, however this must be arranged over the phone or by email and meet a minimum order value of £500.

We always aim to to dispatch orders as quickly as possible, usually within 1 working day. Most orders which are placed by 3pm (Monday to Friday) will be dispatched the same day for delivery the following working day (courier). Orders placed after this time will be dispatched the following working day under the same service. Smaller orders may be dispatched via Royal Mail, 1st Class Recorded (Signed For).

Bespoke items or larger bollard orders generally require an additional 2-3 working days, however if we can dispatch the goods sooner then we will.

If we are unable to fulfill an order within the above times, possibly due to stock, we will be in touch straight away to inform you of an expected delivery date.

Our courier services and Royal Mail do require a signature as proof of delivery. Couriers will sometimes leave goods in a “safe place” or “with a neighbour” by request, however it is not guaranteed. You can make a request when placing your order under the “Customer Notes” section if desired. We will always pass this information onto the courier. We would always recommend making arrangements to ensure that you are available to accept and sign for the delivery. The shipping address does not have to be the same as the billing address, it could be a work address or alternative.

If an order is not delivered due to nobody being available to accept the delivery, the courier should make another attempt and / or leave you parcel at a collection point. We use couriers which provide a 1 hour time slot for your delivery which should make things easier. You can also amend your delivery via text message / online when you receive your initial “out for delivery” notification. It is therefore important to provide a mobile number and email address when placing your order to ensure you receive these notifications.

Firstly, we do try and dispatch orders within working working day (bespoke items excluded). If we are aware of any delays prior to dispatch, we will always contact you to inform you of the issue. Therefore, if you have not received your order within 3 working days of placing your order, please get in touch straight away. You can contact us via telephone on 01327 871161 or email us. We will then contact the courier on your behalf to find out where the parcel is located and report back with any findings. We endeavor to resolve any issues as quickly as possible.

UK Mainland covers a huge part of the UK. Areas which are not part of UK Mainland include:

  • Scottish Highlands & Islands
  • Channel Islands
  • Isles of Scilly
  • Isle of Wight & Isle of Man
  • Northern Ireland

“Dropping ship” is a term used to describe when a Company sends a customer’s order direct to their customer (end user). This prevents additional forwarding costs and results in the end user receiving the goods much quicker. When dispatching “drop ship” orders, we refrain from including Lumena literature, and often include a personalised delivery note from our customers (if provided via email). This makes it less obvious that the goods have been shipped by us, with the only reference to Lumena being the branding of the product and Sender address on the courier label, which is barely noticeable.


Yes, we are always happy to help with lighting plans. We simply ask you to send us a rough plan and the types of lighting you are looking for and we will then advise accordingly. You can find more information about Garden Lighting Plans here.

Yes, of course. Our friendly technical team are always on hand to help, Monday to Friday (9am – 5pm). Please call us on 01327 871161, or contact us here.

Yes. Our current garden lighting catalogues and brochures are available to download here. Alternatively, you can request a hard copy via email or when you place an order.

We strive to provide as much information about our products, most of which is available on each individual product page. Not all of our outdoor lights have a downloadable spec sheet readily available, however we are constantly adding to these. A list of those currently available can be found here, however if you require some information to send to your client on a specific product, please contact us and we will do our best to help.

Need More Help?

If you have any further questions about any other aspects of garden lighting, we would be happy to assist. Please either contact us via Live Chat or email your query via the link below. We aim to reply to all emails within one working day (excluding bank holidays).