This article describes step by step the process of installing and connecting halogen lighting for a wardrobe, as well as recommendations for the selection of the cross section and the allowable length of the wire for connecting 12-volt lamps when using an electronic power supply.
To power the halogen lighting of furniture, a voltage of 12 volts that is safe for humans is often used, since touching such a bare wire is practically not felt. Despite the low power of the lighting devices (in our case, the total power of the lamps is 60 W), the current in such circuits is much higher than in 220-volt ones of similar power. Let’s calculate the current in the primary circuit of the power supply (220 V). In our case, the current is 60 W / 220 V = 0.27 A. The current in the secondary circuit (12 V) is 60 W / 12 V = 5 A.
As you can see, the current in the secondary circuit is 18.5 times higher than in the primary. Therefore, it is necessary to carefully consider the selection of the cable cross-section for this type of lighting. In the selection of the section, it is also important which transformer is used to lower the voltage: electronic or induction. In our case, an electronic power supply is used. For such a unit, the permissible length of wires in the secondary circuit (12 V) should not exceed two meters.
To select the cross-section of the wire for the secondary circuit, use the instructions in the documentation for the transformer, or follow the values given in this table.
Table for selecting the cross-section of a copper cable up to 2 meters long, depending on the total load power:
Total load power (P), W 60 105 150 200 250 300 400 Cross-sectional area of the wire (s), mm2 0.75 1.5 2.5 3.0 3.8 4.5 5.8
Preparation for work
To install the lighting of the wardrobe, we need the following materials:
- two-core copper wire, s = 0.75 mm2 (we select the section according to the table) – 5 m;
- halogen lamps (P = 20 W) – 3 pcs.;
- electronic transformer of alternating current 12 volts (P = 20-60 W) – 1 pc .;
- switch – 1 pc .;
- terminal blocks (I = 3 A, s = 4 mm2) – 9 pcs.;
- self-adhesive cable clamps – 10 pcs.
To complete the work, you will need the following set of tools:
- flat head screwdriver;
- indicator screwdriver;
- side cutters;
- soldering iron;
- Double-sided tape;
- soldering kit (rosin, solder);
Connection diagram for halogen lamps:
When ordering a sliding wardrobe, the seats for halogen lamps were prepared in advance.
Connect the wire to the switch. To do this, you need to open its case. We do this by carefully prying it around the perimeter with a screwdriver.
With side cutters, remove the outer layer of insulation from the cable, strip the wire cores and twist them.
Tinkering wire cores and applying solder to them.
Initially, the switch was supplied with a section of wire and a plug for an outlet. Since the native wire was not of a suitable length, it was decided to remove it and solder the new wire to the existing terminals. This avoided additional connections.
We clean the switch terminals. We trick them and solder the wire strands. It is important that the rosin does not come into contact with the switch. If this happens, it can be removed by wiping the contact with alcohol.
Carefully lay the wires inside the switch body and assemble it.
Now it is important to decide on the place where the switch will be installed. Since it does not represent a great aesthetic value, it would be logical to install it in an inconspicuous place. In our case, the gap between the right side of the cabinet and the wall was chosen. We place the switch on the wall of the cabinet on double-sided tape.
In order to hide the wire behind the cabinet wall, attach it to self-adhesive brackets. To do this, remove the protective layer from the adhesive surface of the staple and glue it to the cabinet wall. After that we fix the wire. We install the staples with an interval of 0.5 meters.
We install halogen lamps in the holes in the top cover of the cabinet.
Since the gap between the ceiling and the top cover of the cabinet is rather small, it is extremely inconvenient to carry out work there. Therefore, we will collect parts in a convenient place for us. And then we will transfer everything assembled to the closet.
We measure a piece of wire from the lamp to the lamp and cut it off. There should be two wires in total: from the left to the center (wire # 1) and from the center to the right (wire # 2).
We clean the ends of wire number 1 and fix the terminal block on them. This will be the point for attaching the leftmost luminaire..
We twist two wires (No. 1 and No. 2) together and connect them with a terminal block. This will be the terminal block for connecting the central lamp.
The ends of wire # 2 are connected to the 12-volt outputs of the electronic transformer using a terminal block. Which wire goes where does not matter. This will be the terminal block for connecting the right lamp.
As a result, we get a wire with terminals connected in parallel..
We fix the terminal block on the 220 V wire, pre-laid in the wall for connecting the cabinet lighting. To do this, be sure to remove the power from the wire!
We supply power to the wire. Using an indicator screwdriver, we determine the phase on the input wire. After turning off the power supply, we make the final connections. The phase will go through the switch to the electronic transformer to the wire marked L. The neutral wire from the transformer (N) is connected through the terminal block to the neutral wire of the existing 220 V wire. Installation is carried out according to the previously indicated diagram. Having connected all the wires, we fix them on the cabinet lid with brackets. The power supply can be attached to double-sided tape.
We position the terminals so that wires from halogen lamps can be connected to them.
We connect the lamps to the terminals. Which wire to which terminal does not matter.
We check the completed work. We serve food. We turn on the lamps using the switch.
Result of work
The lighting is working properly. The wires are hidden behind the top cover of the cabinet, the switch is not visible, but it is convenient to use it. With prolonged operation, the wire does not overheat, since it is correctly selected in cross section. Thanks to the compact arrangement of the wires on the top cover of the cabinet, it will be easy to clean up there. Since the cable is secured with staples, there is no risk of breaking electrical connections during cleaning..