How to disassemble a light switch for repair or replacement
A broken switch is, of course, not a tragedy, but the situation is unpleasant. Fortunately, this device is not particularly difficult, so a repair is available to almost any DIYer who has at least a little experience with an electrician.
First you need to figure out how to disassemble the light switch, and then determine the cause of the breakdown and fix it.
If the light does not light up when you press the key, the switch is not always the cause of the breakdown, you should not immediately begin to disassemble it. First, it does not hurt to check the presence of voltage in the network, as well as the condition of the incandescent lamp. If there is no voltage, the switch is most likely ok.
It is necessary to find out what is wrong with the network (short circuit, disconnection, damage to the supply cable, etc.), and eliminate this damage. It's even easier with a burned-out light bulb - it needs to be replaced. If the network and the lamp are in order, it's time to take a closer look at the switch.
First you need to find the machine on the switchboard through which this particular switch is connected, and move the levers to the “down” position, ie. disable it. After that, use a tester to check the presence / absence of voltage at the output. The procedure is simple and does not take much time, you should not neglect it, even if there is complete confidence that the device is definitely disconnected from the mains.
You can even make an assumption about the nature of the breakdown even before the start of the repair. A common problem is oxidation of the contacts inside the device. If the switch does not work only occasionally, most likely, the reason is precisely in bad contacts, which will simply have to be cleaned. In addition to the oxidation “shell”, carbon deposits can also build up on the metal switch plate. It can also be cleared of accumulations in order to restore the operation of the device.
Improper installation of the circuit-breaker can cause serious damage. Due to inexperience, some amateur craftsmen connect not a phase to the machine, but a zero core. As a result, the switch seems to work, but all the lighting wiring connected in this way remains energized. It happens that a simple replacement of a burned out light bulb in such a network can result in an electric shock. It is enough to fix the circuit for everything to work correctly.
Before disassembling the switch, you must de-energize either a separate line through which power is supplied to the device, or the entire apartment
Such installation errors can also lead to the fact that after the machine is turned off, the line will still remain energized. This is one of the reasons why you should always check, even when the device is turned off. If there is voltage, you need to de-energize the apartment or house. If sparks appear inside the switch each time it is turned on and off, this usually indicates that the contacts of the device are of poor quality.
In some cases, you have to replace the entire switch with the same one, only a new one. Usually, for replacement, the exact same model is selected, which fits both the socket outlet and the interior. If, for some reason, you need to install another model, you should make sure that the existing socket is suitable for it.
The reason for frequent voltage drops in the network can be not only the general condition of the electrical network, but also a large number of powerful electrical appliances that are connected at the same time. You can consult with an experienced electrician about this, you may need to make adjustments to the existing circuit.
How to disassemble a switch
Before you start disassembling and repairing the switch, you need to stock up on the necessary tools: a screwdriver with an indicator or a multimeter, insulating tape, sandpaper, a straight and cross screwdriver, a marker, pliers, etc. Also, some kind of container for storing small items, for example, fasteners, will not hurt.
After disassembling the switch, remember the color coding of the wires and their connection diagram. Detailed shots can be of great help.
Another useful item when performing such work is a camera or mobile phone with a camera. The whole process is recommended to be filmed. Detailed pictures can be especially useful for novice craftsmen during the reassembly of the device.
Dismantling keyboard devices
Disassembly of a one-, two- or three-key switch begins with disconnecting the keys. Usually, each of them needs to be pry off with a screwdriver or other similar device and simply removed. Some manufacturers make small bumps or notches on the keys to make it easier to disassemble.
After that, you should carefully remove the decorative frame. To do this, you need to push back the latches that hold it. The front of the breaker mechanism is now accessible for inspection.
When disassembling a switch with two or three keys, you need to mark the place where the supply wire is connected and remember the color of this wire, or mark the corresponding core with a marker
After that, it is again recommended to arm yourself with a tester and make sure that there is no power at the switch terminals. If work is carried out with a multi-key device, experienced craftsmen recommend marking the power wire common to all keys with a marker. After that, you need to remove the fastening latches or unscrew the bolts that hold the switch mechanism in the socket. Now you can start for a more detailed inspection and repair of the device.
Old rocker switches have a slightly different structure. On the case of such devices, in front or on one of the side panels, there is a fastening bolt, which must be unscrewed. Then you can remove the entire body of the product. For old and new switches, different types of socket boxes are used. This point should be taken into account if you intend to update the device.
The buttons and decorative frames of the switches usually have small protrusions that allow you to pry the element with a flat screwdriver and quickly remove it without damage
Sometimes too rigid fastening interferes with the installation of the keys, then the bolts need to be loosened a little, this usually helps. When disassembling the switch, it is not always necessary to remove the key if it does not interfere with the necessary repairs. In this case, it is sufficient to detach only the frame. The spacer fasteners can be loosened from the side.
The ends of the bare conductors must be securely fastened to the terminals. To make sure that the work is done correctly, you need to twitch the wires slightly after fastening. Any mechanical defects or damage to the cable is a good reason to replace it. Areas where there is damage to the insulating layer should be re-insulated. But if there are too many such areas, it is better to replace the cable completely, otherwise the switch will have to be repaired again soon.
At the end of the repair, the switch must be correctly connected to the wiring again, following the diagram and avoiding mistakes that were made earlier. If wiring has been replaced, insulate the unused ground conductors. Then you should again fix the switch mechanism in the socket box and tighten the fastening bolts. Then the keys and the decorative frame are returned to their place.
Do not overtighten the mounting bolts during reassembly, this may change the position of the device and make it difficult to install the key
Now you need to check the operation of the switch. To do this, turn it on and off several times. For two- and three-key devices, check each key separately and all at the same time. If the device does not spark at the same time, and the light of the lamps does not flicker, the work can be considered successful.
What to do with the rotary switch
Rocker switches are the most common and simplest models. With other options for such devices, some difficulties may arise. Sometimes it is necessary to troubleshoot the so-called rotary switches, also called dimmers.
Dismantling the rotary switch begins by removing the knob. You just need to pull it forward while holding the body of the device.
Such devices are also sensitive to power surges and short circuits, like their “counterparts” with keys. Very often, a triac breaks down in dimmers. This element cannot be repaired, but it can be replaced. You need to start disassembling the rotary switch by removing the adjustment knob.
It is mounted on semicircular elements of the “dad-mom” type or special slots. It is necessary to hold the switch body with one hand, and with the other gently, but with effort, pull the handle towards you. You do not need to twist it. There is a fixing locknut under the handle, it also needs to be unscrewed. Sometimes the fastening is done with a screw.
After unscrewing the dimmer lock nut or fixing screw, you can remove the device case and gain access to its interior.
Unscrew any of these elements counterclockwise. Now you need to remove the plastic cover, as well as the frame, if necessary. Then you should loosen the elements that hold the dimmer mechanism inside and you can remove it from the socket. First, you need to check all contacts, connections and wires, clean up the resulting carbon deposits and oxidation, restore damaged insulation, replace broken wires, etc.
If the triac of the rotary switch breaks down, it must be replaced with another serviceable element with exactly the same dimensions and characteristics.
The damaged triac must be removed and taken to an electrical store to find a new one, exactly the same. The assembly of the repaired device is carried out in the reverse order. As in the case of the key switch, before disassembling, you need to de-energize the line, check the contacts with a tester and record the process in the form of a photo so as not to confuse anything during assembly.
Features of repair of sensor models
Things get a little more complicated when it comes to touch switches, which are turned on not by pressing a key or turning a knob, but by touching. Such models are usually equipped with a radio remote control, they have not only electromechanical filling, but also boards with microcircuits that provide control of the device.
You can use a regular straight screwdriver to detach the touch switch faceplate, but be careful not to damage the element.
To repair such a complex device, the skills of a novice electrician may not be enough. To eliminate complex breakdowns, you will have to invite a master who understands not only electrical engineering, but also electronics. High-quality touch switches rarely break, but if this happens, first you need to study the manufacturer's instructions in order to disassemble the touch switch correctly.
First you need to remove the glass decorative plate. Under it there is a panel with one or more sensors, depending on how many lines (one, two or three) this particular model serves. Usually, the location of the sensors is indicated by circles, as shown on the decorative panel the area that is sensitive to touch.
There is a panel with sensitive elements and control boards under the decorative cover of the touch switch. Under this panel are the connectors to which the wires are connected
Under the decorative panel there are LEDs that indicate the state of the switch: red - on, blue - off. Under the panel with sensors and boards there is a switch mechanism to which the wires are connected. Dealing with the inputs and outputs is pretty simple, much the same as for a conventional rocker switch. The sensor plate is attached to this part with clips. To remove it, you just need to disconnect them.
The main part of the switch, which is installed in the socket, usually does not have any clamps. Regular bolts are used as fasteners. To inspect the places where the wires are connected, you need to unscrew these bolts and remove the switch from the socket. If the breakdown is related to the wiring, it will be easy to fix it.
It is necessary to check the voltage on individual cores, find the faulty wire and replace it. Here, just as when working with other types of switches, it makes sense to clean the oxidation on the contacts, if any. Reassembling is not difficult: connect the main unit to the power supply, install it in the socket box and fix it there with screws, then attach the panel with sensors and the decorative plate.
The protective mechanisms of such switches react to breakdowns by interrupting the power supply. Even if the bulb just burns out, the switch goes to the “off” position, which does not change even if the bulb has already been replaced. In this case, after the repair, you just need to touch the plate to turn on the light. If there are no other breakdowns, the touch switch will work properly.
Contact problems are easy to solve. They need to be examined first. If there is a layer of oxidized metal on them, it should be removed, and then the contacts are reinstalled. If the contacts are not just oxidized, but have pronounced traces of melting, they usually cannot be repaired, you will have to completely replace the device. It is very easy to remove carbon deposits from the contacts; for this you can use a knife or the end of a flat screwdriver.
A visual inspection of the wires both in the box and in the junction box will help identify and eliminate the cause of the breakdown. Damaged elements need to be repaired or replaced completely
When working with wires, you need to pay attention not only to the condition of the uninsulated ends, but also to the quality of the wires themselves. For example, fragile veins can easily break off, break, etc. In this case, some of the wiring will have to be replaced.
Common causes of weakness and disruption of contacts include:
- high humidity, which stimulates oxidative processes;
- incorrect, for example, too weak fastening of the wires;
- excessive loading, as evidenced by sparking, humming, crackling and other similar signs;
- network voltage exceeding the permissible level;
- frequent voltage drops, etc.
To reduce problems with carbon deposits on the switch contacts, experts recommend using energy-saving lamps rather than traditional incandescent bulbs. The load on the network is reduced and the components wear out more slowly.
Correct disassembly of the switch is an important step in the repair of the device. Keep in mind the safety precautions and carefully memorize or photograph each step of this process so that reassembly can also be performed without problems.
