Some garden lights are supplied with clip-on or clamp-on connectors designed to attach to a flat "figure of 8" low voltage cable: these attachments are often unreliable as any flexing of the cable in the attachment leads to erosion of the insulating sheath around the toothed prong which makes the connection into the supply cable. Over time this can lead to a loose connection, which soon gets worse through arcing between the 2 cables. Some lights are supplied with a plug/socket or other connector which may be weatherproof under many circumstances, though not suitable for connections in very wet locations.
Most garden lights other than wall lights, which usually have a connection within the back plate, have a cable fitted; this includes spike-mount, tree-mount, hanging or recessed lights. The best way to make a weatherproof connection to the low voltage cable from a transformer is a cable joint or splice kit consisting of crimped butt connectors for joining cable conductors and heat shrink tubing for sealing the joint. Gently heating the heat shrink tube shrinks the tubing around the joint by a ratio of 4:1 and melts an internal adhesive coating which seals between the tubing and the surfaces inside the joint. This provides a good weatherproof joint for most garden lighting installations.
Fitting a cable joint kit
Elipta's T9962 Cable Joint Kit connects a light to the end of a 1.5mm² or 2.5mm² 2 core ground burial cable up to 10mm overall diameter from a transformer. Strip off 40mm of the outer sheath of the supply and light fitting cables. Use blue butt crimps for connecting 35w-75w lights, which are normally individually wired to a cable direct from the transformer to avoid excessive cable voltage drop. T9962 Cable Joint Kit may also be used for splicing l.e.d. lights or other lower power lights with small diameter or flat connection leads into 2 core 1.5mm cable from a power supply or transformer. Higher grade lights fitted with sheathed rubber cables, including all Elipta's spike spotlights and led lights such as the Navigator recessed range, should be spliced into 1.5mm2 or 2.5mm2 2 core cable using a T9963 cable splice kit.
Crimp blue butt connectors (1) to leads from light fitting (2), staggering the length of the leads to minimise thickness of joint and ensure the maximum length of the joint between cable sleeves is under 100mm. If light fitting has thin cable or leads, slide narrow diameter tubing (3) over cable or leads of fitting (2) and heat shrink in place with a low temperature blow lamp or heat gun to provide a bulkier sleeve. Slide wide diameter tubing (5) over cable from transformer (4). Crimp blue butt connectors onto cable from transformer (4) and test to ensure a good joint. Slide large diameter tubing (5) over the complete joint and heat shrink in place with a low temperature heat gun
Fitting a cable splice kit
Elipta's T9963 Cable splice kit connects a light into a run of 1.5mm² or 2.5mm² 2 core ground burial cable and connects a light to the end of a 4mm² 2 core ground burial low voltage cable, which is particularly recommended for 75w-100w recessed uplights. T9963 comprises one length of 19/6mm adhesive-lined heat shrink tube and 2 yellow crimp butt connectors. 20w halogen lights or led garden lights fitted with rubber sheathed cables may be spliced into a 2 core 2.5mm cable from a transformer using T9963 cable splice kit.
Slide wide diameter tubing (5) over cable from transformer (2). Crimp yellow butt connectors (T9963) or blue butt connectors (T9962)(1) to the supply cable conductors (2). Twist wires from light fitting (3) to conductors of cable running to next fitting (4) and crimp into the other end of the butt connectors; stagger the length of the leads to minimise thickness of joint and ensure the maximum length of the joint between cable sleeves is 100mm. Test to ensure a good joint, slide tubing (5) over joint and heat shrink in place with a low temperature or heat gun. Silicon sealant may be injected into the tubing prior to shrinking as an additional precaution in especially damp locations.
It is always a good idea prior to heat shrinking the joint to connect the lighting circuit in order to ensure that all electrical connections have been properly made and that all lights work. Cable joint and splice kits are not intended as underwater joints for continuous immersion in water features: underwater lights supplied with long cable already fitted are recommended.
Copyright 2014; Information based on products supplied by Lighting for Gardens Limited and is advisory only. The company accepts no responsibility for incorrect use or application of information given. Light fittings can become hot in use; exercise appropriate precautions. Exterior electrical installations should be undertaken by a qualified electrician.