Size fuses are made according to GOST R IEC 60269-3-1.In particular, the names of "traffic jams" in the documents there. Instead, the phrase is used - fuses with a lamp base. This means that the holder, as a rule, is made of ceramic. And the thread corresponds to edisonova. And now, starting from the above information, let's try to consider what kind of electrical fuses or plugs are.
How does an
fuse work? Inside any fuse there is a replaceable part. Sometimes it is mounted in a ceramic case or passes inside a sealed glass flask. The meaning is the same: when the current rises to a certain value and is held, in a fraction of a second the vein burns. Usually the holder is sold directly with the fusible insert, marking is applied on it. Suppose:
- Rated current. The value that the cork can withstand for a long time.
- Price. Recently, this part of the marking has lost its importance, it is used less and less.
- Year of manufacture sometimes absent.
- Climatic design according to GOST 15150.
When the current significantly exceeds the rated value, the fuse-link burns out for a short time. The flow of energy through the flap ends. The design of the fuses is different. Separate ones are placed on contact grippers, others are placed inside holders. The last option, most readers see in the access shield. Look at the varieties of electrical fuses.
Versions of electric fuses
The device of an electrical fuse strongly depends on the type, and there are 6 of them, according to GOST R IEC 60269-3-1.Let's start with the first, and the USSR known to the majority at the time is on the 6th place( if not specified separately in the text of the standard, the tripping currents are determined according to table 6 GOST R 50339.0).
First frame size D
Detects threads under E14, E18, E27, E33 and regular metric. A distinctive feature are fusible inserts with a ceramic body and a filler of quartz sand. The shape is far from always cylindrical; mutual non-interchangeability is provided by the use of bushings. For current up to 10 A, such measures are not used. Each of the six versions of frame size D shows its own type of holder body, rated current. Mix randomly fail. The marking uses a fusion cross-section of copper-nickel alloy. The design feature of a number of sizes D is recognized as a recess in the middle of the lid, where the clamping screw rests. Such fuses are additionally protected against vibrations. There is no chance that the cork will turn off and the contact will be lost. The rest of the size D II at E27 is fully used instead of conventional traffic jams.
Cylindrical Fuses( II)Type A
- s are available for rated currents of 6, 10, 16, 20, 25, 32 and 63 A. The last two values in a row for a voltage of 380 V. These are ordinary cylindrical fusible inserts without a holder. Standard sizes on diameter are from 23 to 38 mm. The case is ceramic; the filler is a series of dielectrics. Values of the operating current is selected according to table 6 GOST R 50339.0.With the exception of two of the ratings indicated immediately( in GOST R IEC 60269-3-1): 6A nominal - 24A actuation, 10A nominal - 110A actuation. These fuses, as is clear from the appearance, are inserted into any cartridges and elastic terminals suitable for the diameter of the contact pads, but are designed specifically for bases with two contact pads on the ends. The text slips a remark that copper is used as a conductive material. If this plays a decisive role, be careful in choosing clamps for cylindrical fuses type A.
- Type B cylindrical fuses differ in size( diameter, length), rated currents and mounting method: in this case the clamp terminals are meant. Other holders are also used. For example, in the form of a parallelepiped with a cylindrical hole in the center, at both ends of which is located on the contact pad. The fuse is inserted from the end.
- C type cylindrical fuses show a distinctive feature in the form of a color marker protruding above one of the contact pads. This part is immediately judged on the rated current. The full table is given in GOST R IEC 60269-3-1, we briefly list the main ones: 10A - red, 16A - gray, 25A - yellow. There are 5 sizes, from zero to fourth. Moreover, the last two( 3 and 4) on the cylindrical part have a circular ledge. However, the diameter is difficult to confuse. For the above “special” sizes, these are 13.7 and 22 mm. Holders are any terminals where space is left under the color marker( in the form of pits, deepening a round shape under the butt).The direction of the inclusion of a cylindrical fuse type C in the circuit does not matter.
Fuses with pin leads( III)
They look like a rectangular capacitor with thick legs. The design consists of a body with two legs( holder) and a fusible insert directly. The rated current is calibrated by bushings. Those who have come across banana-type connectors for measuring equipment will certainly note similarities. The fuse feet with pin connections show a cut in the center. Current grading is carried out by changing the sizes( including holders).Calibration sleeves are made difficult to remove, so as not to confuse the ratings.
For use in plug-type fuses, the features do not differ. The size is such that it was possible to put in a holder made of ceramic or other material( contact diameter 6 mm, length 26 mm).
In these fuses, gG fusible plugs are used, which are general-purpose, operating over the entire range. The case is exclusively ceramic, there are no separate fuse options. For example, today’s rectangular PN-2 with an end arrangement of flat legs. Before it was about the types of electrical fuses for low voltage. According to the rules, this is up to 1 kV, but in reality it is 220 - 380 V. Protection of electrical networks with fuses of this type is not always possible. In addition, only technical conditions have been developed for selected types of products( as in the case of PR-2), costing money( for enterprises), and it is not possible to get such a document in simple use.