The plug in combination with a socket is a quick-release contact connection. Thus, almost any modern equipment is connected to the network. This method is reliable, simple and convenient if all components of the system are operational. Otherwise, the plug in the outlet becomes hot or there are other problems.
Defective plug
When connected, one or more symptoms of malfunction may be observed: sparking, heating, fusion. If at least one of them is noticed, it is necessary to repair, because in this situation the risk of short circuit and fire increases. In addition, the user may receive an electric shock.
Often only one element from the contact pair, in particular a plug, is damaged. If it heats up 5-10 minutes after turning it on, it needs to be repaired or replaced. How the problem will be solved depends on whether it is understood or not. If the case is monolithic, the wire suitable for it is cut off, and a new plug is installed in place of the old plug. If the case is collapsible, it is necessary to unscrew the screw connecting its two halves, inspect the insides, eliminate the malfunction and reassemble the plug.
The reasons why the plug heats up in the outlet are reduced to a violation of the contact of the legs with the wires supplying electricity. Contact is broken due to such factors:
- Loosely tightened bolt that presses the bare end of the wire to the contact leg. You need to pull it more carefully.
- Burnt or melted wires. The wire should be shortened by cutting off the damaged area, again strip the ends of the insulation and fasten them properly with screws.
- Oxidized contacts and wires. Contact areas can be cleaned with a knife or sandpaper to a metallic sheen, use acid to etch. If the wire is oxidized, cut it and collect the connection again.
After repair, two halves of the housing are tightened with a screw and checked whether the plug is heated or not. If the problem persists, consider other causes of the problem.
In addition to physical damage to the plug, heating may be caused by improper use of the appliances. This includes:
- Insufficiently stable contact between the plug and the socket. If the diameters of the contact legs of the plug and the holes in the outlet do not match, this leads to heating of the plug housing. Insert the plug into the outlet and move it with swinging movements. The presence of play indicates that it is necessary to disassemble the socket and tighten the plates wrapping the electrodes, or replace the socket completely.
- Using an outlet to connect appliances with plugs that have different electrode diameters. Gradually, the contact petals loosen and grip the thin pins loosely, which is why the plug and socket are heated with it.
If none of the above causes are identified, most likely the outlet is faulty.
Outlet failure
Checking the outlet is carried out by connecting to it an appliance with a working plug. After 5-10 minutes, check the temperature of the plug and socket. If they are hot, it means that the outlet needs repair, or it does not fit the plug-in device according to its characteristics. For example, a powerful device - an electric stove or a vacuum cleaner, and the outlet is not designed for high current strength.If the case remains cold, you need to once again check the plug, which was heated when connected - the reason is its breakdown or that it does not fit a specific outlet.
If the outlet is broken, it must be disassembled, inspected, diagnosed and eliminated. Possible reasons:
- The contact plate does not press the wire well - the screw must be tightened.
- The spring-loaded contact is damaged - the spring is loose, missing or broken - it is pressed or replaced with a new one.
- The plates that wrap around the electrodes are deformed - they can be bent, pinched.
- The wire inside the outlet melted - you should remove the damaged area, remove about a centimeter of insulation and reconnect the bare tip to the clamping plate with the screw.
- The internal elements of the outlet melted - it is impossible to fix anything here, it is necessary to replace the outlet with a new one.
Before performing work related to the repair of the outlet, it is necessary to de-energize the apartment completely or only the line that includes the faulty element.
Heating due to wiring
The reasons why the plug connection is heated are more global and independent of the state of specific devices. For example, the electrical network may not be designed for heavy loads.
- There is a wiring in the old house, which was laid at a time when it was not necessary to operate a large number of powerful electrical appliances: air conditioning, microwave and other things.
- The wiring is done independently, the calculations are incorrect.
- The wiring was laid by the workers, but they were not qualified enough and made mistakes in the calculations.
In these cases, solving the problem will not work in any other way, except by replacing the wiring. It is recommended to lay a copper wire of sufficient cross section.
The contact pair heats up if the plugs are connected via a tee - powered from one socket or inserted into an extension cord with several outlets - connected in series. The load in these cases is summed up, and it can exceed the permissible one.
Wire fracture
The plug or socket will overheat if the wire inside is broken. At the fracture site, the minimum cross-section of the wire, which is not enough for the flow of current of a given force. Resistance increases, and with increasing resistance, heating of the wiring occurs. In addition, a wire fracture is accompanied by microscopic sparking. Sparks additionally heat the damaged area.
Load detection using wire cross-section
In order to control the possibilities of wiring and determine the maximum load for a particular electrical network, it is necessary to find out the cross-sectional area of the wire and perform the calculations:
- First, determine the diameter of the core using a vernier caliper. The actual cross-sectional area is found by the formula: Sph. = 0.785 * D2. Instead of “D” substitute the measurement result.
- To calculate the specific current and power, it is necessary to find the difference between the maximum and minimum values in the interval in which the calculated cross-sectional area falls. The difference in the specific current strength is divided by the difference in the cross sections in the same interval, where index 1 is smaller and index 2 is more important, namely Iud. = (I2-I1) / (S2 / S1). The value is obtained in A / mm2. The specific power is found in the same way: Nsp. = (N2-N1) / (S2 / S1). The desired values of current and power are calculated by the formulas: Iisk. = (Sf.-S1) * Iud. + I1 and Nisk. = (Sf.-S1) * Nud. + N1.
If the values obtained during calculations are less than those indicated in the instructions for electrical appliances, the cause of heating is poor electrical wiring.
Why is the wire heated in electrical appliances and extension cords?
The heating of the wire in electrical appliances is caused by a disproportionate ratio of the cross-section of the wire and the current flowing through it.If the wire is thin, and the device is powerful, for example, an electric kettle or an electric heater, thin wires heat up. The same thing happens if the device with a cable of sufficient diameter is connected to the outlet using a household extension cord.
The socket is heated on the washing machine
If the outlet that the washing machine is connected to is heating up, this phenomenon can be caused by the following reasons:
- Disproportionate power of the machine connected to the outlet - on the outlet body it is indicated what power it is designed for. If the numbers do not match, this will inevitably cause overheating.
- Poor contact of the plug with the outlet is observed when the Soviet-style plug is connected to the Euro outlet. The electrodes of the Soviet plug are a millimeter thinner, and therefore the contact density is less.
- Malfunction of the outlet itself. Visually, it can be diagnosed by the presence of cracks, fused sections.
- Weak contact petals of the outlet. Due to careless operation, the clamps may loosen.
None of these causes will resolve itself. Measures should be taken to eliminate it.
The heater plug is heated
A water heater is a powerful appliance. A boiler, for example, has a power of 1.5 to 2.5 kW, and its amperage reaches 12 A. If the plug, socket or cable is heated so that it is impossible to touch them, the possible reasons are as follows:
- the cable has a cross section of less than 2.5 mm2;
- there is a bad contact of the plug in the outlet;
- the water heater is connected through an extension cord;
- a poor-quality or old-style outlet is installed.
Heating the boiler plug is acceptable, but the temperature should be within the normal range. A hot, but not scorching body without traces of melting is not a cause for concern.
Heat elimination
Repair of electrical appliances begins by turning off the power supply in order to completely protect themselves from electric shock: they turn off the machine or turn off the plugs. Unscrew the screw in the central part of the socket, fixing the plastic cover. Make an external inspection of contacts and wires. If damage is noticed, it is necessary to remove the socket from the seat by loosening the screws that hold it. Then you should cut off the damaged wires, strip them again, place them in the contact clamps and carefully clamp them.
If traces of fusion are visible on the plastic casing around the holes for the electrodes, there is most likely a poor contact of the electrodes with the contact petals. The problem is solved by tightening the petals with pliers.
If, after the manipulations, the cause of the heating has not been eliminated, the plug of the appliance is probably defective. It is necessary to check the contacts inside it. And this is only possible if the plug is collapsible. During a visual inspection, traces of melting wires inside will be noticeable. Repair consists in removing the damaged area and reconnecting the wire to the electrode with a screw. Monolithic forks cannot be disassembled.
When a socket or plug is being heated, they immediately repair or replace damaged items. It is important to prevent short circuits and fires that occur suddenly in such situations.
To protect yourself, you must follow the rules for operating electrical appliances, do not exceed the maximum load on the network and abandon the use of extension cords and tees.
