The working principle of contactor

(a) as shown in figure l shape and structure diagram for ac contactor.Ac contactor is made up of four parts:(1) the electromagnetic mechanism electromagnetic institutions by the coil (armature) and static and dynamic core acmotor2.blogspot.com core component,its role is converting electromagnetic energy into mechanical energy,electromagnetic suction contact action.(2) the contact system Including the main contact and auxiliary contact.Main contact for on and off the main circuit,usually for three to normally open contacts.Auxiliary contact is used to control electric circuit,the electric interlocking effect,so it is also called interlocking contacts,normally open,normally closed two of each.(3) arc generator stator extinguishing device capacity has more than 10 a contactor in arc extinguishing device,for small capacity of contactor,often with double fracture contact arc extinguishing arc plate,electric arcing,alternate with arc and clay arcing cover arcing.For large capacity contactor,adopt longitudinal seam arcing cover and grid arcing.

(4) other parts including reaction spring,buffer spring,spring contact pressure,transmission mechanism and shell,etc.1 a arcing cover 2 a contact pressure spring 3 and 4 main contact a reaction a coil spring 5 6 a short circuit ring 7 8 a spring 9 move www.dongfeng-motor.com a static core core 10 a auxiliary normally open contact 11 a auxiliary normally closed contact of the working principle of electromagnetic contactor is as follows:after the coil current,flux and electromagnetic suction in core.The electromagnetic suction makes the armature and overcome the spring force,drive the contact agency action,open normally closed contact,normally open contact closure,interlock or connection.Coil loss of electricity or on both ends of the coil voltage decreased significantly,the electromagnetic force is less than the spring force,makes the armature release and contact agency reset,disconnect lines or terminate the interlock.Dc contactor (2) :the structure and working principle of dc contactor is basically the same as the ac contactor.On the structure and the electromagnetic mechanism,contact system single phase asynchronous motorand arc extinguishing device and other parts.Due to the dc arc than ac arc is difficult to extinguish,dc contactor magnetic blow type arc extinguishing device is often used to arcing.

Nameplate parameters

Motor nameplate data and rating Model:the series of varieties,the performance of the motor,protective structures,such as rotor type product code.Rated power:it means the runtime on the output mechanical power rating of the motor shaft,unit KW electric vehicle motor or HP,1 HP = 0.736 KW.Voltage:directly to the line on the stator winding voltage (V),the motor has two kinds of Y and delta connection,the connection shall be consistent with connection of regulation of motor nameplates,to ensure that corresponding to the rated voltage.Current:motor under rated voltage and rated frequency,and the output power rating of the stator winding current of three-phase line Motor vehicle Frequency motor,which refer to connect the ac power frequency of 50 hz + 1 Chinese regulations Speed:motor under the rated voltage,rated frequency,rated load,motor speed (r/min) per minute;The 2 pole motor synchronous speed is 2880 / min.The duration of the work quota:refers to the motor running.Insulation class:the level of motor insulation materials,decided to allow temperature rise of the motor.Standard number:said design motor technical documents basis.Excitation voltage:refers to the synchronous motor excitation voltage (V) when the rated work.Field current:refers to www.dongfeng-motor.com the synchronous motor excitation current (A) when the rated work.

Motor burn out phase characteristics

Lack of electricity,a phase star connection will burn off two phase coil.Delta,meet will burn a coil.Lack of two phase electric,star connection will burn a coil.Delta,will burn off the two coils 1.The interphase short circuit.If found in three phase generator short circuit fault phenomena,fusing many wire,the nearby have a lot of molten copper scrap,and the other or the other end of coil group were no sear, Can be concluded that the winding burn was caused by phase fault.2.Lack of phase operation.Burn out motor winding due to lack of phase operation,and the damage characteristics of general is obvious.Open the cover of a motor,if you see the winding end a third or two-thirds of extremely Group of burn black or dark brown.wholesalemotor.blogspot.com And the rest of the two phase or a phase winding is in good condition,can be concluded that the winding burn was caused by lack of phase operation.3.The turn-to-turn short circuit.Because of turn-to-turn short circuit and burn out motor winding,the obvious features of the damage,if the end coil can clearly motor fan see that there are a few turns or burned in a volume group,a very very Electromagnetic wire was burned into bare copper wire,and the short circuit part outside of nature or other two phase coil is intact or burned a little,can be concluded that is turn asked short-circuit winding burn.