Garden Lighting Cable Guide

There are three types of main cables in the Techmar range. There is a 8m, 10m and a 15m. There are two common questions we get about cabling regarding the mains cable.

The SPT3 cable is a larger cable (cable size 10mm x 5mm) and is capable of taking 150 watts of loading, whilst the SPT1 cable is smaller (cable size 5mm x 3mm) and will take a maximum of 120w. The smaller SPT1 is more than adequate in most garden lighting systems now when using energy saving LED bulbs.

NB. It is always good practice, when using both SPT3 & SPT1 main cables in a continuous run, end to end, to try to start with the bigger SPT3 and connect the SPT1 cables after. This helps reduce any potential problems with "volt drop" on longer cable runs that are approaching the system recommended maximums (as stated below)

Manufacturers Maximum Cable Lengths

The recommended guidelines for joining cables is up to 80m with a maximum load of 120W on our 150W transformer. We would reccomend using either the SPT-3 or the new deluxe cable for distances of this length.We have however supplied systems that are much longer. LED based systems especially perform well using more cable. If you are in any doubt please call us for more help.

Do You Actually Need A Mains Cable?

Well the simple answer is no. If you are for example, running a set of decking lights and your power supply is on or close to the decking, you can simply go from the transformer directly to the lights.

Once you have laid out your mains cable around your garden, you are now in a position where you need to get that power to your lights. All lights in the Techmar range (at time of writing) come with either a 1m, 1.5m 2m or 3m cable. So for the most part this should be enough cable to reach your mains cable. But what if it's not? Well that's where the extension cables come into play. There are 5 in the range: 1m, 2m, 3m, 6m and a 10m.

The smaller 1, 2 and 3mtrs are very useful for adding that extra cable for difficult to reach lights such as wall lights. The 6m and 10m cables are ideally used as a lead in cable. For example if you want your lighting at the bottom of your garden, you don't want all your connectors to be in the first 15m. So by putting a 10m extension cable between the power supply and the 15m mains cable will allow all your connectors to be in a more useful position. The 10m extension cable can also be used to reach very remote lights.

What is Volt Drop you ask? Well is where the voltage going through the light system drops the further it goes. This means that you could have a light or two, furthest away from the transformer, looking a little dimmer than the rest. If you tested the voltage at the furthest point of a big system. It would not be 12 volt, it could be 9 or 10 volts. Therefore, the reduced voltage may produce less light from the fittings towards the end. This was a much bigger problem in the old days for Halogen systems. To rectify this the manufacturer tests and produces LEDs that are designed to operate at full output with a reduced voltage input, thus eliminating Volt Drop on much bigger systems. This is not guaranteed as various things lead to Volt Drop, i.e system loading, transformer sizing and whether Techmar manufactured LEDs are being used.

If you are in any doubt, please call us as we have many years’ experience in designing and supplying systems.