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FAQ's - Frequently Asked Questions About Low Voltage Garden Lighting

We've tried to provide clear and helpful information on Frequently Asked Questions (FAQ's).

If you have a question and can't find the answer in this section, or feel the answer can be improved, please drop us an email or call us!

We'll answer your question and if appropriate add it to this section to benefit other readers.

FAQ thumb

Do you have a brochure I can look at and print?

Yes, the Lumena Outdoor & Garden Lighting brochure 2018/2019 is available to view, share and download from here.

Lumena recently published New and Upcoming Outdoor & Garden Lighting Products for 2021-2022 in a brochure update available to view, share and download from here.

New in 2022!

NEW BROCHURE! Discover Modern Design, High Quality Outdoor Lighting from in-lite The Book of in-lite 2022.

2021 BROCHURE The Book of in-lite 2021.

Who are Techmar?

Techmar are a Dutch company specialising in plug and play garden lighting products under the garden lights brand. See our full page at 'Who are Techmar'

Are the older RING system garden lights still available? 

No, but some older garden lighting systems were marketed under the name RING and replacement products for the older systems sometimes can be found on Ebay. We have a helpful blog about replacing a RING transformer here .

Are garden lighting products compatible between brands and manufacturers?

Leading outdoor and garden lighting products from in-lite, Lumena, and Konstsmide are designed for outdoor use with their own low voltage system. in-lite lighting fixtures include a unique cable connector to connect to in-lite cables and the transformer. Konstsmide offer a plug and play connection that is intended for connection to Konstsmide cables and transformers.

Lumena offer the VERSA plug and play garden lighting system and many 12v lighting fixtures are available as bare-wire to connect to existing low voltage cables and systems where 12v cable junction boxes are used.

Outdoor and garden lighting systems labelled "Plug and Play" are NOT universally compatible. If unsure, please do contact us and we can help.

Do you sell Solar Lights?

Our 12v lighting products are powered by 12v AC electricity. This comes through a transformer plugged into a normal (or waterproof) 3-pin electrical 230v socket.

Why don't you sell Solar Lights?

We specialise in safe low voltage outdoor and garden lighting that works on 12 volts and designed for outdoor use with a 12v lighting system. However, we do recommend Lumena Pro-Solar Lights for professional outdoor use.

Why do you use LED bulbs?

LED's are used as they save energy and last longer.  See our full page LED Technology & Energy Saving

Where does the 230v 3-pin electrical socket need to be? 

The socket can be either indoors or outdoors.  

If it's outdoors then it should be encased in a waterproof casing as the plug attached to the transformer needs to be waterproofed.  

An example of a waterproof socket box is shown below and they can be obtained from places such as B&Q, Screwfix or Toolstation or your local electrical supplier.

What do you mean by a waterproof electrical socket?

The image shown below is a waterproof electrical socket

230V 2 Gang RCD Switched Socket Housing

The image is from the Screwfix catalogue (BG Nexus 13A 2G RCD Switched Socket - Product Code: 91095) but equivalents are readily available from good electrical wholesalers.

An RCD is a residual-current device, or residual-current circuit breaker (RCCB), is a device to quickly disconnect current to prevent serious harm from an ongoing 230V electric shock.

All transformers are weather proof but we just think it's good practice to house them.  It keeps the British weather off the transformer's casing and cables; and just helps tidy the view!  You can paint the boxes too if you don't like grey!

We use simple weatherproof boxes (e.g. from Screwfix - IP55 Enclosure) but again readily available elsewhere. 

IP55 Weatherproof Housing Box

NB: If you leave the transformer outdoors, whether or not it's housed, make sure it's lifted and fitted well off ground to avoid being flooded or buried in snow; and use common sense when near to water bearing fittings such as down pipes, leaking gutters, ponds etc.

Do I need an electrician?

You should only need a qualified electrician to install and certify (for Building Regulations) any new 230v cabling and sockets.  

If you have existing 3-pin sockets (indoors or watertight) then you can simply plug the transformer into one of them.

How do I choose my cables?

Firstly you should think about where you would like your light fittings to go.  

It's best to draw a sketch of your garden or outdoor area (e.g. a drive or steps) and then mark on the sketch where you want the fittings.  From that you will be able to estimate various distances such as where the first light is in relation to the 230v mains connection.  You then build up a list of what cables are needed to reach your fittings.

There are various low voltage cables available from our suppliers.

In-lite cables are supplied in various lengths. With the in-lite garden lighting system you are in full control where to install the connectors to suit your lighting design. This removes the need to carefully plan where the connectors will fall when planning for your cable design.

The Konstsmide range of cables are supplied with pre-fitted plug & play connectors. Each light fitting has a connection lead that simply 'plug' into the connectors allowing some flexibility on the final sighting of the light fittings or if you want to add or move fittings later.

A more detailed description is given in Stage 3 of the page Choose Your Products

If you need help then feel free to phone, email or send your sketch to us and we'll be delighted to help.

How far can I run a length of 12v low voltage cable?

We have installed 12v low voltage cables as far as 65 metres and at the end of the cable used three 30 watt LED floodlights for up-lighting some large trees!  The layout was carefully considered and designed so don't leap to a conclusion that a 65 metre run will work 'out of the box' for everyone.

We think we could have cabled a lot further, up to 90 metres, especially if the high consuming LED floodlights had been low consuming spotlights (e.g. the installed 3 x 30 watt LED floodlights = 90 watts were replaced by say 10 x 4 watt LED spotlights = 40 watts).

The cable run was supplying 11 fittings in total amounting to 122 watts consumption powered by a 150 watt transformer. 

(We give information about our cables here )

So can we give a definitive answer for everyone?  Answer: No.

Each situation is different and it's a tricky one to answer as it involves a few variables that need to be looked at closely.

Low Voltage - Look Closely At The Variables Image

We always try to understand the:

  • total 'possible' cable length
  • LED fittings likely to be used and where sited on the run
  • overall cabling and fitting design to suit the layout of the garden or outdoor area and
  • the size of the transformer!  


THE MAIN VARIABLES - a short 'lay-mans' explanation!

Hopefully the following brief 'lay-mans' explanation may help.  It's not written to harmonise totally with the 'laws of electricity' but to try and give a picture in the minds eye. 

If it doesn't help then have a look at our webshop for further information ( or email and we'll be pleased to help.


1 Electricity Loss

All electricity loses power as it goes along a cable.  The longer the cable the more it loses.  

The nearest analogy is a normal domestic hosepipe with a constant water pressure forcing the water through it.

You can imagine that if the hosepipe is short, the water would come out almost as quickly as it went in.  If the hosepipe is 200 metres long the water would trickle out.  

Electricity passing through cables is just the same.  As electricity passes down the cable it loses power.  It's called 'line loss' (not pressure loss).

So it's perfectly true to say that a 230v mains supply running through your garden has more power and therefore can reach further than a 12v supply (all matters being similar). However, it's also a potentially dangerous cable whereas a 12v cable is never dangerous!

2 What is being used by the LED's and where are they on the cable run?

The next main variable is what is being used along the cable by each LED and where they are sited on the cable run.  If the fittings are using a lot of electricity, especially at the beginning of the cable run, then then the length of supply will be shorter before the power runs out.  

Again, imagine a large sprinkler being used at the beginning of a hosepipe and that it uses most of the water.  The end of the hosepipe will only trickle out what's left!

3 Minimum and constant supply

Thirdly, LED technology typically likes to have a constant AND 'minimum' voltage to ensure it works.  So if some fittings at the earlier part of the cable use more electricity and 'drain' the supply then others that may be downstream may not work at all.

4 Total electricity being used.

Then there is the total electricity being used.  The transformer must be able to supply sufficient electricity to power all the light fittings. This can be controlled to some degree by the transformer's output and how many 'watt's it can supply for consumption by the LED bulbs. However, if the total wattage of the LED's being powered is more than the transformer can provide then some LED's won't work.  Never have more 'watts' being used than the transformer can 'output

(for further information See 'How Do I Choose My Transformer? below)

What is a transformer?

For our products, a transformer is the electrical box that takes more dangerous high  230v AC (Alternating Current) and reduces or 'transforms the electricity into safe 12v AC (Alternating Current).  An example would be the boxes that you get with child's train and Scalextrix sets.

(Want to know more?  The BBC have a great, but very simple, technical explanation.  

see here .  

Wikipedia have a far more detailed description at

How do I choose my transformer?

You can do some simple calculations to work out what is needed for all your lights.  You need to add up all the 'watt's from each electrical light bulb you want to have and then make sure your transformer wattage output is larger than the total.

For example, if all your lights are the same, just multiply the number of lights you need by the light bulb 'watts' you have chosen.  Each fitting has it's 'watts' shown in the product description.  Then get a transformer that is bigger than your total 'watts'.

For example, 10 LED lights at 4w each will be 40 watts (10 lights x 4 watts each = 40w).  So a 60w transformer will be suitable.

If you need help then feel free to phone, email or send your sketch to us and we'll be delighted to help.

NB: We do try to carry out a quick check when you order and we'll contact you if we spot something that may be odd.

Can I join the larger 150 watt SPT-3 to the smaller 120 watt SPT-1 cable?

Yes you can!  

The Plug & Play connectors are a standard size and are pre-fitted at the factory to each type of cable.  So it's easy to just plug the ends of each different type cable together, screw the fitting down to make it watertight and then switch on!

Can I lay 12v garden lighting cable straight onto a hardcore base before my patio is laid?

Most patios, drives and pathways are laid on top of a hardcore base that is typically 100mm/ 4" to 150mm/6" in depth.  The weight of vehicles and general footfall typically dictates the depth.  Slabs, blocks, tarmac etc are then laid on top of that hard base structure.

Some hardcore bases are topped of with a sand layer for laying blocks whilst other hardcore bases are left 'bare' as slabs with a mortar-base can be laid direct.  A tarmac 'base-course' also sits straight onto a compressed hardcore base.

The hardcore material is made up of stone aggregates of different sizes, angles and textures that when compressed ('whacked down') 'lock' together to form a very hard base.  There are various hardcore types but the most often referred to is 'MOT Type 1'.  MOT is an old reference to when roads were specified by the UK's  'Ministry of Transport'. 

We would NOT recommend...
Laying 12v garden lighting cable straight onto a hardcore base (between the top of the compressed hardcore and the bottom of the slab, tarmac or blockwork) or in a trench run through a hardcore base for the following main reasons:
  • The hardcore aggregate has angular and sharp pieces of various sizes that help it to lock together when compressed.  Whilst it may have been 'whacked' down using machinery before cable laying, there is always the possibility that part of the 12v cable (PVC sheath insulator) gets pierced by any sharp point of aggregate when the finish layer is laid (slabs, tarmac etc). This can 
      1. create an immediate non-working electrical circuit if the piercing is aggressive or
      2. reduce the life of the inner core cable with water ingress and result in failure at an unknown future date
        • Slabs are typically laid on either a full bed or mortar (our Landscaper's preferred method) or on 'dots and dabs' of mortar.  Either way, the cable will be subject to a mortar coating.  Mortar contains cement which is naturally corrosive and whilst we've never tested the long term effect of mortar (made with cement) on the outer sheathing of the cables we feel it's sensible to avoid the problem.  It'll probably last for years but we don't know!
        • Asphalt ('Tarmac') 'base-courses' are also made up of pretty large sized aggregates with sharp edges to help them 'lock together' and are covered with asphalt or bitumen.  Worse, they are typically compressed using a heavy roller after laying onto the hardcore base.
        In all of the above the cable(s) is also permanently fixed and if a failure should occur it will entail a lot of work to rectify.
        We would recommend...

        Laying the 12v cable in a run of plastic or other form/construction of conduit or ducting.  Almost anything can be used as the conduit will protect the cable from being pierced or being corroded. 

        The conduit or ducting can easily be laid onto/into compressed hardcore by simply easing a small channel along the ducting-run, so that it lays roughly flush to the top of the hardcore.  It doesn't need to be perfect, too neat or pretty.  It's going to be buried after all!

        Cheap plastic piping or small diameter drain pipes from the DIY stores, Screwfix, Toolstation, Plumbers merchants etc will be sufficient.  It also allows for the cable to be withdrawn and new cable inserted at a later date if needed. 

        If you are unsure have a look at something like this from Screwfix Tower Conduit Heavy Gauge 25mm x 2m Length Black Product Code: 46738

         Low Voltage Garden Lights - 25mm Conduit Image

        Try and get a pipe/conduit that will allow the 12v Plug & Play end-connectors to clear the inner bore of the conduit/ducting.  

        The Plug & Play end-connectors are 19mm in diameter.  

        So if you need cable protection a minimum 25mm conduit is the best choice.  (A smaller diameter conduit may work but it makes drawing a cable through tricky and if any dirt gets in it'll be a go for a minimum 25mm diameter!) 


        TIP: An alternative is to use an old piece of 'hosepipe'.  In this case the hosepipe can be split along its length with a Stanley knife and the cable can be progressively eased into it.  The 12v Plug & Play connectors won't pass through as the typical inner bore of the hosepipe in the UK is about 13mm and a connector is about 20mm diameter.  Hence the need to split it and ease the cable along the length of the hosepipe.


        This provides a solution that will protect adequately but is not the best solution for cables needing to be withdrawn/re-inserted. 


        However, it's a good protector for any 'sharps' from hardcore, tarmac or the corrosive properties of mortar.


        A further method, if your slabs have been laid but not grouted, is to lay the cabling along the slab joints and simply Geofix over the top.  If you have to negotiate a right angle bend, then just make sure the cable is NOT laid at a sharp/too tight and precise right angle.  Allow the cable to form it's best natural shape around corners so the cable and it's plastic insulation isn't stressed.

        Finally, the 12v cabling when powered up is totally safe, so if through any reason the cable does get pierced, even from inside a conduit/duct then no harm to any individual will occur!


        Can I lay 12v garden lighting cable through a lawn?

        Yes.  The cables are fine for laying through a lawn. If the cables have connectors attached then make sure all caps etc are fully tightened and waterproofed.
        Our recommended method is to take a spade or lawn trimming tool and scar/open the lawn (dig into the lawn) for about 4"/10cms. 
        Then using the spade or lawn edger 'open' the lawn by pushing backwards and forwards.  As soon as the lawn is 'opened' push the cable down to the bottom of the slit/scar and move onwards.  Work your way through the grassed area until you get to the end of the run. Once all the cable is sitting in the scar/opened area then heel over the lawn and it'll repair when the grass grows again in a similar way to laying new turf.
        We recommend encasing the cable in some old hosepipe (or similar conduit) for about a 6"/15cm into the lawn and 6"/15cm into the garden border at the edge of the lawn.  This protects the 12v cable from the power of any strimmer line and also gives a better visual for later as to where the cable run actually reveals itself from under the lawn. 

        Is your technology compliant with the latest EU Directives?

        Yes.  The products are compliant with the European 'ECO Design' Regulation 1194/2012 (click here for a very technical download EcoDesign_Regulation_eu-verordnung-1194-2012-en.pdf ).  Or check the directives on the European Union website

        What happens if I want more lights after I've installed them?

        Depending upon the transformer you purchased you may have enough power to simply add other cables and lights.

        Using the example above do a quick calculation and see what spare 'watt' capacity you have based on your transformers strength.  Our suggestion is don't get right on the limit as you'll be using all the capacity all the time. For example, if  your additional lights take you to 59 watts and you have only 60w left in your current transformer then we'd recommend getting a larger transformer.

        Another way is to split the 'circuit', have a separate transformer and run another, separate, cable run with the new lights attached.

        Are 12v LED lights 'value for money'?

        To answer that you have to understand what is meant by 'Value For Money'.

        This is a combination of 'economy, efficiency and effectiveness'.


        LED's are normally more expensive than traditional bulbs (depending upon the quality of the product you purchase). So typically you can get twice the number of 'traditional bulbs' for the same price as an LED bulb!

        However, the lifetime of a traditional bulb is significantly less and you'll need to replace them more often.  

        Why?  Because normal bulbs 'blow' after a far shorter number of hours use.  LED's typically are manufacturer rated for more than 10,000 hours or more per bulb before they fail.  So you'll need to use more 'old style' bulbs when compared to LED's.

        On a pound-for-pound basis LED's are far better economic purchases.


        LED technology has improved significantly over the last few years and they typically use about the tenth of the energy for a similar light output.   The running costs for 'electricity used' makes them massively more efficient than the standard type bulb.


        Assuming that LED bulbs are as effective in lighting the area when compared to old style bulbs then there are no advantages or disadvantages.  

        So, 'Are LED lights value for money?' We say a resounding 'Yes!'  But we would say that, wouldn't we!  

        In short they are far better 'value for money' than other older products.  

        More Information is shown in our page LED Bulbs and Energy Saving

        How many lights do I need?

        This is almost unanswerable.  Read our Lighting Design page to get some ideas

        Is the cable good quality cable?

        Yes, all materials are quality assured and the cables are no different.

        Types of 12v garden lighting cables

        The following information is referenced from: (

        The main difference between SPT-1, SPT-2, and SPT-3 is the thickness of the insulation that surrounds the copper wires, with each SPT wire having a thicker insulation than the previous. Generally, a cable with a thicker insulation will also have a higher maximum amp rating.

        SPT cables feature stranded copper conductors and polyvinylchloride (PVC) insulation, and resist oil, water, acid, alkali, and ozone. All three types of cable are rated up to 300 volts and 60°C or 105°C.

        SPT-1 Wire is the most popular cable. SPT-1 has an insulation thickness of .030”. Because it has the thinnest insulation of the SPT wires, it also has the lowest amperage.

        SPT-2 Wire features a thicker insulation than SPT-1 wire at .045” thick. As a result, SPT-2 also has a higher maximum amp rating, and is able to handle more power.

        Because of its thicker insulation, SPT-2 cord is often recommended for lower temperatures where the insulation may get brittle and crack. However, the thinner insulation on SPT-1 wire tends to be more pliable, so some professional installers believe that SPT-1 is actually better for cold weather.

        SPT-3 Wire is the newest type of SPT cable, and it also has the heaviest construction. While SPT-3’s insulation ranges from 0.060” to 0.110” thick, its maximum amp rating does not greatly vary from SPT-2 wire’s amperage.

        Can I use the system for security purposes?

        Yes. In-lite 12v transformers have a motion sensor built into the transformer unit. The lights will then be triggered appropriately.

        Can I have timer switches?

        Yes, there is a timer control also built into the in-lite 12v transformers.

        Are the lights fixed in the same spot?

        If the lights are are 'ground spikes' (e.g. Corvus) then you can move them about as each light comes with its own length of cable.  Post lights would normally be sited in a permanent position.

        If you fix your light to a wall or fence with the wall fixing kit then as long as you move the fixing kit and you have enough cable then they can be moved also. 

        What does MR and GU on lights mean?

        It's the reference to the physical size and type of a light bulb.

        TheGreenAge (the UK’s premier energy saving advice community for heating, insulation & renewable technologies), have a simple description at

        But if you don't have time to look there then...

        • MR lightbulbs have two 'thin pins' that 'push fit' into their connector.  These are typically 12v type fittings.
        • GU lightbulbs have a two-prong 'bayonet type' connection that you 'push and then twist' into it's connector.  These are typically 230v fittings.

        If you are adding to an existing set it's important to understand if your lights are powered by 230V or 12v and which type of bulbs you have.  It's also worth making a note of the wattage used - it's normally noted on the bulb metal or plastic at the connector end.

                    Bayonet fittings 230V      Pin fittings 12v (see MR16 picture)


        Low Voltage Garden Lights - LED fitting types

        (MR stands for 'multifaceted reflector' and it's the reflecting side of the glass that's covered by a reflective coating. MR16, is 16 eighths of an inch or 2 inches (5 centimeters) in diameter at its largest circumference, hence the name "MR16." Other sizes include MR8 (1 inch, or 2.5 centimeters, diameter) and MR11 (1-3/8 inch, or 3.5 centimeters, diameter).

        What is Stainless Steel 316?

        Stainless steel type 316 is the main stainless used in the marine environment, with the exception of fasteners and other items where strength and wear resistance are needed, then Type 304 (18-8) is typically used.

        The composition is shown in the table below.

        Type Analysis of Stainless Type 316:
        Carbon 0.08% max. Silicon 1.00% max.
        Manganese 2.00% max. Chromium 16.00-18.00%
        Phosphorus 0.045% max. Nickel 10.00-14.00%
        Sulfur 0.030% max. Molybdenum 2.00-3.00%


        If any product has 'Grade 316' shown then its marine grade stainless steel.  Otherwise it is Stainless Steel grade 304.

        Further reading can be found at the British Stainless Steel Association (see )

        What does IP68 mean?

        IP 68 is a code following the International Protection (IP) Marking conventions.

        It classifies and rates the degree of protection provided against intrusion (body parts such as hands and fingers), dust, accidental contact, and water by mechanical casings and electrical enclosures. It is published by the International Electrotechnical Commission (IEC).

        IP68 means it is dust tight, waterproof and the fittings are submersible to 0.5m depth.

        All products are suitable for outdoor use (apart from the 3-pin plug that if used outdoors should be housed in a watertight socket housing). 

        For further reading on IP ratings see

        Can you get a spark or be electrocuted from 12v lighting?  Are my children and animals safe?

        The products we supply are all Plug & Play with internal connections.  There is no risk of electrocution if a cable gets accidentally broken, when you join two cables together or fit a light to the cables.  If children decide to explore the fittings they will be safe and if an animal bites through a cable then it may get a 'little tickle' and no more!

        Do you install tree or decorative lights?

        Yes we can install the lights in trees of any height as we have professional climbers who are able to do it for you.  They can also de-install afterwards.

        The lights can be easily fitted to pergolas and other features in the same way as normal Christmas lights are fitted outdoors.  

        Can your lights go underwater?

        Not all lights are capable of submersion but those with an 'IP68' rating can go into water up to 0.5m.

        What guarantees come with the products?

        All the products are high quality and rarely fail.  LED bulbs can fail (for example if a football is kicked at a post and the post gets badly knocked) but this is very rare too as LED's are more resistant to shock damage.

        If you have a failure then contact us as we want to give great service to you. Clearly, there are the standard obligations to replace failed products in the first 12 months but we don't think you'll be contacting us about that.  So just email us with your problem and attach photo's if necessary and we'll respond a.s.a.p.

        Can the lights be surface mounted?

        Some low voltage light fittings can be surface mounted on walls, fences or other harder structures (e.g. wall lights and certain spotlights).  Some low voltage light fittings are designed to be inserted into the ground or into patios or decking and are therefore 'flush fitting' once installed.  If you need any advice on fixings or suitably please do contact us and we'll be glad to help.

        I'm a Garden Designer/Landscaper - how can we proceed together?

        Before raising an order that commits you to a large financial outlay, it's sensible to discuss with us the design, your client requirements, the garden aesthetics etc.  

        The last thing you (or we) want is to commit to a large order and find that the client isn't happy.  This involves the hassle of product returns, re-stocking fees, client issues and problems; and worst of all a potentially damaged reputation for you!  

        Sure, we can help with lighting designs and cable runs and between us we can normally design a great solution at arms length.  However, a really good and practical way to proceed once the design is tabled is to raise a small 'working/sample set' order.

        It's something we've done many times before if doubts exist either over the substance (materials look and feel), style of a fitting, the overall lighting effect or you have a very hands-on and demanding client.

        You will want your clients to be happy.  We want that as well!

        Of course the 'lighting effect' can only be perceived at dusk/night time but far better to install a small 'mock up/pilot' and get the client's 'buy-in' before any large purchase is made.  It demonstrates a professional and caring attitude and the client should see the value of the proposition.  This reflects really well on you (and ourselves in the background as a silent party to your plan).

        It also builds confidence in the mind of the client such that when you attend to the installation activities you can do so with confidence that the client is totally happy.  You can then potentially repeat the same process (or install what's already been approved beforehand) for any additional lighting in other parts of the property.

        (NB There is an added benefit in that you will gain valuable experience as well and be stronger in your understanding and recommendation.)

        We can also discuss warranty issues and that no manufacturer (in Lite, Techmar, Konstsmide) will be prepared to cover a warranty where their systems haven't been installed 'as a whole'.  We always try and encourage a complete manufacturer system from transformer, through cabling all the way down to fitting and light source.

        However, you may be faced with installing a 'mixed manufacturer' system (e.g. non-manufacturer cables, mixed manufacturer connectors).  Sometimes this is a necessity to hook into older systems or avoid a complete re-cabling exercise that is simply impractical 'on site'.  However, we always have to step aside from any warranties as we are unable to stand on the manufacturer to underwrite them.

        Whilst we are aware of mixed manufacturer systems being totally adequate, there's always a small risk of a problem and we can't lean on the manufacturer if it's a mixed system.  It's not in our terms with them so we can't pass that benefit on to you.

        Just call us to discuss the best way forward and we'll be delighted to help.