Fuse, transformer and communicate contactor identifying to choose (on)

One, fuse fuse is a kind of the simplest and significant protection electric equipment. When use, fuse is strung together in receiving the circuit that protects in place, use as circuit and the short circuit protection of the equipment that use phone. 1. Fuse structure fuse basically has insert the type such as type of type, screw type, airtight canal. 1) insert type fuse the graph is shown 1 times is to insert type fuse, main by porcelain lid, porcelain, move touch head, static touch the composition such as head and frit silk. Commonly used product has RC1A series, basically use at the short circuit protection of low-pressure branch circuit. 2) the appearance that the graph shows screw type fuse 2 times is screw type fuse and structural sketch map, basically cover by canal of porcelain cap, frit, porcelain, on the composition such as next terminal, terminal and base. Frit canal is made by electrical engineering pottery and porcelain, mix of fuse-element inside frit canal quartz arenaceous filling, frit has an indicating device in tubal upper cover, when fuse-element fusing indicator jumps out to show fuse-element fusing. The short circuit that basically is used in circuitry of low-pressure distribution ark is protected, model of screw type fuse tags type to be: RL € - € € / RL of ① of ⑥ of ⑤ of ④ of ③ of ② of ① of € € is code name of screw type fuse; ② designs code name; ③ pole is counted (3P, triode, sheet pole is not tagged) ; Graph porcelain of 3- of canal of frit of 2- of cap of porcelain of 1- of structure of A) appearance B) covers fuse of 2 screw type 5- issues the terminal on 4- fuse of ④ of terminal 6- base supports a rated electric current; ⑤ fuse-element is rated electric current; ⑥ wiring means (Sa, electric platoon type) . 3) the graph shows airtight fuse tubal form 3 times is outline drawing of airtight fuse tubal form, canal of main You Rong, fuse-element and place a composition, cent has packing type to be mixed without packing type two kinds. Graph 1- places fuse of type of 3 airtight canals a canal of frit of 2- base 3- without filling fuse of airtight canal type does not have filling airtight fuse tubal form is a kind dismountable fuse, its characteristic is when fuse-element fusing, the generation inside the canal is high-pressure can destroy quickly arc. Can ravel after fuse-element fusing change new fuse-element. Basically use at producing the situation of overload and short circuit breakdown often. Without filling model of airtight fuse tubal form tags type to be: RM € - RM of ① of ③ of ② of € ① is not to have filling code name of airtight fuse tubal form; ② designs code name; Rated electric current is worth ③ fuse. Have filling airtight fuse tubal form has filling airtight fuse tubal form is in frit canal fill quartz is arenaceous wait for medium material, quartz is arenaceous the heat conduction performance with be had better and insulation property, its grain can draw electric arc energy, make electric arc cools quickly, accelerated destroy arc ability. Basically use at the short circuit of cable, lead, electromotor, transformer and other wiring to protect. Have filling model of airtight fuse tubal form basically has RT and NT two kinds. RT series tags type to be: RT € - € € / RT of ① of ⑤ of ④ of ③ of ② of € ① is to have filling code name of airtight fuse tubal form; ② designs code name; ③ fuse is rated electric current; ④ wiring means (Q, form of the wiring before bottom seat, h, form of the wiring after bottom seat) ; ⑤ fuse-element is rated electric current. NT series fuse is the product that introduces production of technology of German AEG company, it is one kind has tall disjunction ability to have filling airtight fuse tubal form, domestic code name is RT16. Its model tags type to be: NT € - € / NT of ① of ④ of ③ of ② of € ① is low-pressure tall disjunction have filling code name of airtight fuse tubal form; ② fuse-link dimension; ③ fuse is rated electric current; The rated voltage of ④ fuse-link. The graph that fuse pursues medium in electric principle and article character date see a picture 4. Graph 4 fuse graph and literal symbol 2.

Fuse is main technical parameter 1) it is normal that rated voltage shows fuse can be long-term voltage of the susceptive when the job, its are worth the rated voltage that be equal to commonly or is more than electric equipment. 2) when when rated electric current shows fuse permanent worker is made, each component temperature rise does not provide a value more than can susceptive electric current calls fuse rated electric current, and frit physical ability has flowed for a long time and be not called by the electric current of fusing fuse-element is rated electric current. Its are worth the rated electric current that should be more than or is equal to electric equipment. 3) it is OK that disjunction ability shows fuse is below the formulary work requirement such as rated voltage the anticipation of disjunction short-circuit current value, namely fuse is OK the value of the biggest short-circuit current of disjunction. 4) protective character says to install second character again, point to the relation of the I of fused electric current of fuse-element and fusing time T. The quantity of heat of the generation when electric current passes fuse-element and electric current become direct ratio through time, electric current is bigger, criterion fuse-element fusing time is shorter, its feature curve sees a picture 5. Graph the I¥ in graph of character of 5 fuse protection is the smallest fused electric current or weigh critical electric current, when the electricity that carries fuse-element namely is less than this electric current won't fusing, so IN of rated electric current should be less than choice fuse-element I¥ . 5) fuse is fused coefficient normally fuse fuse-element of rated electric current and the smallest fused electric current call fused coefficient than IN/I¥ , general IN/I¥»1.

5~2, the protection of fuse of this coefficient report when overload is characteristic. If want to make fuse can protect small overload electric current, fused coefficient should low; When be being started to avoid electromotor short when electric current, fused coefficient should choose fuse-element tall. 3.

Fuse is chosen 1) fuse type is chosen measure electromotor or illume circuitry to Xiaorong, had considered voltaic protection commonly, should pick the fuse-element material of lesser and fused coefficient, be like plumbic stannum alloy or RC1A series fuse; To high capacity electromotor or illume circuitry, cross the ability of the disjunction short-circuit current when short circuit considering even outside voltaic protection except the consideration, when anticipating short-circuit current is lesser, the RM10 series fuse that the RC1A series that can choose fuse-element to pledge for copper and fuse-element pledge for zinc, when anticipating short-circuit current is bigger, appropriate chooses the fuse of RL6 series screw type that has tall disjunction capacity, when anticipating short-circuit current is very big, the RT12 that needs to choose appliance to have taller disjunction capacity or RT14 series fuse 2) rated voltage chooses fuse to rated voltage should is more than or be equal to the rated voltage that is in electric control circuitry. 3) the short circuit protection that rated electric current chooses fuse-element to wait for resistor sex load to electric stove, illume, IN ³1.

1I, the IN in type, fuse-element is rated electric current, i, circuit job electric current. When protecting an electromotor, start the influence of impulse current considering electromotor, IN ³ (1.

5~2.

5) INM, the INM in type, electromotor is rated electric current. When protecting much stage electromotor, IN ³ (1.

5~2.

5) I Nmax+S I NM, the INmax in type, most high capacity electromotor is rated electric current; ∑ INM, the others electromotor is rated voltaic summation. 2, transformer transformer is to use electromagnetism induction principle, the dormant and electric equipment of alternating current of commutation alternating voltage, commutation or commutation impedance comes true between many winding with same frequency. 1.

Control transformer controls transformer to apply to frequency to be 50Hz~60Hz, in inputting voltage not to communicate the circuit of 660V more than, often regard the control of general electric equipment in equipment of of all kinds Electromechanical as the power source of power source, local lighting and indicator light. Its are electric graphic symbol and literal symbol see a picture 6. Graph the control transformer with electric graph and commonly used equipment of literal symbol Electromechanical has transformer of 6 pairs of winding JBK, BK two series. JBK series tags type to be: € of J B K - € - J of ① of ⑥ of ⑤ of ④ of ③ of ② of € ① expresses a machine tool; ② B expresses transformer; ③ K expresses to control; ④ designs code name; ⑤ nominal capacity (VA) ; ⑥ core form (C, tab type, p, roll piece) . BK series tags type to be: € of B K - B of ① of ④ of ③ of ② of € ① expresses transformer; ② K expresses to control; ③ designs code name; ④ nominal capacity (VA) . 2.

Middling of circuitry of 　 electric control uses three-phase transformer three-phase winding is common the transformer of three-phase core type of a core. The high-pressured winding head end of each photograph and extreme use U1, V1, W1 and U2, V2, W2 to express respectively, and the head end of each low-pressure winding and extreme use U1, V1, W1 and U2, V2, W2 to express respectively. High-pressured winding can use astral form or triangular connection, and low-pressure winding uses astral form connection, respective electric graph and article character date see a picture 7. Graph 7 three-phase transformer is electric graph and star of literal symbol A) - triangle of astral wiring B) - series of transformer of astral wiring three-phase tags type to be: € of € of € of € of S € - € / S of ① of 　 of 　 of ⑧ of ⑦ of ⑥ of ⑤ of ④ of ③ of ② of ① of 　 of 　 of 　 of 　 of 　 of 　 of 　 of 　 of 　 of € 　 expresses three-phase transformer; ② insulation code name (C, shape solid is isolated from, g, air is isolated from, insulation of oily dip type does not express) ; ③ cooling code name (F, wind is cold, p, force oily loop refrigeration, natural refrigeration does not express) ; ④ is pressure regulating code name (2, have carry pressure regulating, empty and pressure regulating do not express) ; Code name of ⑤ winding lead (1, aluminum steel, copper cash does not express) ; ⑥ designs serial number; ⑦ nominal capacity (KVA) ; Grade of voltage of winding of ⑧ high pressure (KV) . 3.

Transformer chooses 　 transformer to choose the rating of main basis transformer. The make choice of of power source voltage that goes up to side winding according to receiving the rated voltage U1 of side, the rated voltage U2 that chooses side 2 times again, U3. 2 times side voltage utmost has the transformer when the belt is laden of 5% pressure fall, output rated voltage to answer because of what this chooses load of summary prep above is rated voltage. 2 side the rated electric current of each winding (I2, I3) should not be less than rated load electric current, the nominal capacity P2 of 2 side is decided by total capacity, computational formula is: P2 = U2´I2+U3´I3+ ... . CNC Milling