What are the components of transformer overhaul?

(1),hanging out of the body,overhaul,body (core,coil,generator generator set tap- changer and lead);(2),maintenance safety cover,oil storage tank,gas,heat pipe throttle single phase generator and casing;(3),and cooling device and oil filter equipment,(4),filter oil or oil changes,if necessary,dry processing.(5),the access control and measuring instrument,signal and protection device;6,clean up the shell,if necessary,paint;All landowners,assembly and measurement and test.(1),hanging out of the body,overhaul,body (core,coil,tap-changer and lead);12v mini generator motor (2),maintenance safety cover,oil storage tank,gas,heat pipe throttle and casing;(3),and cooling device and oil filter equipment,(4),filter oil or oil changes,if necessary,dry processing.(5),the access control and measuring instrument,signal and protection device;6,clean up the shell,if necessary,paint;All landowners,assembly and measurement and test. Advantages of wound asynchronous motor can be through the collector ring wholesalemotor.blogspot.com and brush,plus resistor in series with the rotor loop,to improve the starting performance and can adjust speed change and resistance within a certain range.But the wound,more complicated than the squirrel- cage asynchronous motor structure,poor reliability of the movement of the price is more expensive.

Some problems that should be paid attention to when the PC program

The application of programmable controller (PC),we often encounter of the relay control system transformation problem,then we tend to refer to the original relay control circuit to prepare the PC application. In programming,therefore,we should pay attention to the PC electrical motor control system and relay control system some different on the way to work.Because of the relay control system is a "parallel" way to work,and its contact on-off needs certain action time. So when the starting circuit,time relay KT delay time,KT whether can continue to ac induction motor keep the current state,"parallel" two actions need to be considered at the same time process: KT normally closed delay off contact,KA1,losing electricity KA1 normally open contacts disconnect; KT normally open delay contact closure,KA2 electricity,KA2 normally open contact wholesalemotor.blogspot.com closure. The results of the two process function,to determine the status of KT. At the same time,the existence of the action time of the contact,makes the circuit in time sequence. So the circuit can not reliable work. If join the empty boxes in the loop,and as shown in high efficiency electric motor figure 1 the KA2 normally open contacts into KA3 normally open contacts (see figure 1) brackets. As a result,KT,the KT itself lost electricity,will not continue to maintain current state.

The selection of ac contactor and operation maintenance

(1) to electrical motor choose:(1) rated current of the primary loop contacts should be greater than or equal to the rated current,accused of equipment control motor contactor should also be considered the starting current of the motor.In order to prevent frequent operation of contactor main contact ablation,frequent movement of contactor rated current can reduce use.(2) the electromagnetic contactor coil rated voltage is 36 v,110 v,220 v,380 v,the electromagnetic coil allows within the scope of 80%~105% of rated voltage.(2) operation maintenance:(1) check in the operation of the project:1) by the load current is within the contactor ratings;2) contact points and the signal is consistent with the circuit state;3) running sound acmotortrading.blogspot.com is normal,have because poor contact and heat discharge;4) with or without electromagnetic coil overheating electromagnet short-circuit rings with and without exception.5) arcing cover any loose and damage;6) auxiliary contact with and without damage;7) transmission part with and without damage;8) have running environment without adverse factors of running around,such as too much vibration is too large,poor ventilation,dust,etc.

(2) maintenance:in electrical equipment maintenance work,to maintain the contactor shall work.1) external maintenance:a.external dust cleaning;B.check all fasteners are loose,especially the conductor connection parts,prevent loose contact and fever;2) contact system maintenance:a.check of dynamic and static contact position is,whether the three-phase closed at the same time,the contact spring should be adjusted if you have any questions;B.check contact wear,wear depth shall not be more than 1 mm,contact burning,welding off,must be change in time;When slight loss,generally does not affect the use.Clean the contact is not allowed to use sand paper,should use the plastic file;C.and measuring insulation resistance,electrical motor resistance of not less than 10 m Ω;D.check whether the auxiliary contact action is flexible,contact schedule should comply with the specified value,check whether there is any loose fall off on contact,found the problem,should be timely repair or replacement.3) maintain core parts:a.cleaning the dust,especially the moving parts,and between the core and interface;B.check the fastening situation of iron core,iron core run loose cause noise increase;C.core end ring have fall off or break to repair in time.4) electromagnetic coil maintenance:a.measuring coil insulation resistance;B.the coil insulation discoloration,aging,coil surface temperature should not exceed 65 ° C;C.check the coil wire small electric motors connection,if there are any open welding,burning loss should be timely repair.5) arcing cover parts maintenance:a.check whether the arcing cover is damaged;B.arcing cover any loose and location changes;C.remove arcing cover gap within the metal particles and sundry.


(3) working principle of the vacuum contactor,vacuum contactor with vacuum arcing medium,its main contact seal in a special vacuum arcing tube.When operating coil electricity,armature,absorption in the contact spring and vacuum tube autistic force under the action of contact closure;Operating power coil,the armature reaction spring overcome vacuum tube autistic force release,off contact.Contactor breaking current,the contact gap formed by metal vapor can be formed in the platinum scale,affect the service life of the contactor.

Electrical fault

 Has become more and more widely used in the production of electrical equipment,and electrical failure is inevitable,how to search and eliminate electrical fault according to the fault phenomenon is facing a big problem.Electrical maintenance personnel is to face and solve the outstanding problems electrical motor of the main technical force,in actual production application can accurately locate the fault,and troubleshoot make electrical equipment can steadily run normally every maintenance personnel is fork service motor run capacitor and responsibility.The article illustrates the general steps of electrical troubleshooting and troubleshooting methods.In the practical work,we will meet different electrical fault,the generation of electrical fault electricalmotor1.blogspot.com is strange,troubleshooting methods and ways can only according to the specific situation of the fault,no strict mode and method,will be difficult for part of the maintenance personnel,in the process of troubleshooting,tend to go asynchronous motor a lot of detours,even cause bigger loss.As a maintenance electrician,in case of electrical failure,can accurately find out the cause of the problem,reasonable troubleshooting correctly,to improve labor productivity,reduce the economic loss and safety in production is of great significance.

The generation of arc

When using switch electrical disconnect current,if the circuit voltage not less than 10-20 v,current not less than 80~100 ma,electrical contact between will produce electric arc.Arc is free gas of high temperature and high electrical conductivity,it not only has a lot of damage to contact,and prolongs the time that disconnect circuit.Therefore,in the structure and working condition of the switch

electric acmotortrading.blogspot.com before,first to

see how its produce and put out.The formation of the arc is contact between neutral protons

(molecules and atoms) is the process of free.Switch contact separation,the distance between the

contact is small,high electric field intensity E (E = U/d).When the electric field intensity exceeds

3 x 1000000 v/m,the electrons on the surface of the cathode electric field force will be pulled out

of the free electrons to form a contact space.

This free way is called:strong field emission.The free electrons emitted from the brake

rotorcathode surface and the contact between the original a few electronic,in under the

action of electric field force to accelerate the anode movement,constantly and neutral particles collide on the magnetic motor way.As long as the electronic velocity v is

high enough,the kinetic energy of the E = mv2 is enough big,can from the nature of playing

electronic,the formation of free electrons and positive ions.This phenomenon is called collision

free.New form of free electrons also accelerated motion to the anode,similarly will free with neutral particle collisions.Collision ionization is continuously as a result of the contact between full of electrons and positive ions,greatly conductance; Under the applied voltage,arc medium is punctured,the circuit again by conduction.

Contact arc burning gap between called arc gap.Arc,arc gap between the heat on the surface of the cathode of the electrons gain enough energy and emission,outward form thermoelectricity field emission.At the same time under the action of high

temperature (arc center part to electric motors

pricemaintain the temperature can reach more than 10000 ℃),irregular hot gas neutral

particle movement speed increase.When have enough kinetic energy neutral particles collide with each other,will be free and form electrons and positive ions,this phenomenon is called thermal dissociation.Increase with the distance separate contact,the contact between the electric field intensity E gradually decreases,and the arc combustion is mainly rely on thermal free

maintain.Between switch electric contact,free process at the same time,also happening to the

disappearance of a charged particle free process.

Three-phase asynchronous motor wiring diagram

Three-phase asynchronous motor wiring diagram:three-phase three-phase motor stator winding of each phase winding has two thread ends.A head is called the head end,on the other side called terminal.Provisions of the first phase winding head end use D in table 1 ,end in 4 D; The second phase winding head end with D2,said end D5 said; The third phase winding end of the first represented respectively with D3 and D6.The electric vehicle motors ix thrum import terminal block wiring Column,the terminal marked accordingly D1~D6 tag,as shown in figure (1).Six of the three-phase stator winding end three-phase stator windings can be a star or triangle,y connection is a three-phase winding End up in parallel,the D4,D5,D6 three terminal with copper link together,and the three-phase winding head end access three-phase ac power supply respectively,the D1,D2 and D3 access A and B,respectively C power supply,as shown in figure (2).And triangle by law is the first end of the first phase winding to the 1 D connected to the end of the third phase winding D6,access to another phase power; The second phase winding head end with D2 At the end of the first phase winding connected D4,access to the second phase power; Head end of the third phase winding D3 connected to the end of the second phase wholesalemotor.blogspot.com winding D5,and access to the third phase power supply.In the wiring board will be answered Line column and D6 D1,D2 and D4,D3,and D5 with copper connected respectively,then access to the three-phase power supply respectively,as shown in figure (3).An electric motive is pick a star or triangular,should regard factory rules For,available from the motor nameplate.Is the first of the three phase stator winding end manufacturers set beforehand,never can be arbitrary,but a first end of the three-phase winding up can be reversed, For example will be the motor fan end of the three-phase winding D4,D5,D6 upside down as the head end,D1,D2 and D3 as an end,but never separate the ends of the head of a phase winding upside down,otherwise will produce wrong wiring. If wrong wiring junction box found raw,or winding end of the first mistake,light can't the normal starting motor,long electricity causes starting current too big,motor heating is serious,affect the life, Or burning motor winding,or cause the power short circuit.