Replacing the fuse: when it's done, how to get the job done

Proven for many decades, the best protection against excessive overloads in the electrical network is the fuses that are installed at the input of the supply current systems. Their design and principle of operation are focused on the timely disconnection of the consumer from the network, thereby warning him about equipment breakdown and the possibility of replacing the fuse.

Device, types and principle of operation

A fuse is an electrical switching device that is designed to disconnect a protected electrical circuit by opening it or destruction (combustion, melting) of specially provided current-carrying elements during the passage of a high current through them voltage. Its main elements are a body, a fusible metal insert and a contact part.

The principle of operation is quite simple: if a high voltage is applied to the network, the insert melts, which is usually made of porcelain or fiber materials. The insert is an obligatory element of all fuses; inside it is an arc extinguishing device. All devices that are used to protect electrical installations,

can be divided into four classes:

1. With a fusible link, that is, with a conductive element. When some kind of failure occurs in the network and the voltage reaches its maximum, this element begins to melt from overheating. This is how the voltage is removed from the circuit of an electrical device. Conductive parts are made primarily of metal, most commonly copper, lead and iron. The principle of operation here is that a working balance is created when excess heat is removed.
2. Mechanical devices. They are inserted into a cable that is short-circuited. But thanks to this device, the cable is opened, and the dangerous voltage is no longer supplied to the electrical installation. In protective devices of this type, there is a sensor that monitors the current strength.
3. Electronic fuses. They have built-in transistors that are responsible for current switching. If the current increases and it exceeds the permissible value, the contact closes, and the high load on the conductors ceases to flow.
4. Self-healing. These elements are disabled in the event of an emergency, but remain functional. As long as the insert is cold, it conducts electricity. As soon as it heats up to a certain temperature, the resistance increases and it loses its conductive properties. After the insert has cooled down, current can flow through it again.

Fusible protective elements are considered the most reliable and are relatively inexpensive. It is very easy to diagnose them for serviceability. To do this, you just need to look at the detail in the light - it will be visible whether the melt is intact or not. They are produced in a glass case. When using them, you don't even need to install transformers. Fuses are divided by their size into micro, mini (14-15 mm), norm (18 mm) and maxi (34 mm).

To work in high voltage circuits, other types of protective mechanisms are also used: gas, liquid. There are even shooters. Under normal conditions, they cannot be seen - they are very powerful equipment.

Replacing fuses in the car

In everyday life, motorists troubleshoot the fuse in the simplest old-fashioned way: they put a so-called bug. But here one should turn on the mind and take into account that one day this pseudo-device will not work, and a fire may occur. If some parts of the car are denied, then there is no need to rush to the store to buy new ones.

Often the reason is only in the closureand the car fuses should be checked. In modern cars, there are usually two such units. One of them is located in the salon, and the second is in the engine. The cabin unit can most often be found behind the steering column panel, where the luggage compartment is, or under the seat. On the case of the units on the back side there is a marking on which the name of the devices or the icons corresponding to each of them are indicated.

After the failed site has been found, it is not difficult to find the burned one among all. Then you need to make sure that it really burned out. Visual preview will do nothing. It happens that the jumper remains intact, but the fuse itself does not work. This can happen due to oxidation of the metal on the element. There is a more accurate verification method. To do this, you do not need to remove the element from the socket. First you need to turn on what has stopped working: headlight, horn, lift, etc.

Then you should check if there is voltage at the specific fuse. If at least one of the terminals is not energized, the fuse is blown and needs to be replaced. Step-by-step replacement instructions:

1. Find the block to which the burned-out devices are connected.
2. Select the appropriate fuse for the appliance. Marking will simplify the search.
3. Get it out of the block. Special tweezers, which are sold in a set with a safety block, will help in this.
4. Once again, carefully inspect and make sure of the malfunction.

It is worth noting that it is not so easy to go to the store and buy a quality product that will not burn out in a few hours and will not cause a fire. Before giving money for a purchase, you need to carefully examine the appearance of the product. If there are doubts about the quality of the purchase, then it is worth testing it before installing.

The test order is as follows:

1. Buy a spare just in case.
2. Connect the wires to the metal ends of the device, one to the plus, the other to the minus.
3. If a good fuse is caught, it will immediately burn out, a poor-quality fuse will only melt, it cannot be installed.

Now you can proceed to the most important stage - replacement. To do this, you need to put a new one in place of the burnt one, but there are some points to pay attention to:

1. First you need to eliminate the cause of the short circuit, otherwise this one will also burn out.
2. If the ampere value in the failed device is less than in the fuse, the spare part will burn out and the fuse will not be able to react.
3. The ampere value is determined by the color of the plastic case.
4. The primary circuit fuses must withstand at least 0.1 second at ten times the primary current.
5. There should be no exposed wires on the safety block that can come into contact with the case, so that a short circuit does not occur.

After everything is finished, you need to check again all the existing electrical components in the car. A successful replacement will be then if no more problems arise in the operation of the machine.

Algorithm for working with a microwave oven

Most modern microwaves do not have high-voltage fuses, so the power protector takes over their responsibility. But it burns out only if a double load is applied to the transformer. In case of breakdown you need to do the following:

1. Disconnect the product from the network.
2. Open the top cover; expose the housing of the high-voltage device and check if everything is intact.
3. When the thread burns out, pull the fuse out of the case, check the contacts for burning, clean them, insert a new element with the same parameters.

For those users who are new to the oven design, additional recommendations are needed. To remove the top cover without any problems, you first need to find all the fasteners and carefully remove them from the slots. During visual inspection, you can use a magnifying glass to accurately establish the presence of the filament, as well as to clearly see the markings on all elements. A new fuse must be purchased with a blown one with you so that they are identical, otherwise the thread may burn out immediately after switching on.

Reviews of motorists