Soft starter is in cold cut the application of machine

Key Words: Soft2starter; AC Motor; Starting Performance Of Motor; Wide steel of preface of MCC Controlling Cabinet1 joins make friends factory cold cut machine procrastinate by electric machinery of a 90kW move, before be being transformed of this electric machinery starting is frequency quick resistor is started, the electric current that start is in 380A above, the time that start is in 3min above, the electric current when electric machinery is moving is 70A, because start electric current big and time is very long, mix to resistor of terminal of slip ring of electric machinery rotor, carbon brush, wiring, frequency quick advocate of contactor touch a head to often damage, when be being started as a result of its, want to generate bigger impulse current (the 5 ～ that are Ie commonly 8 times) , at the same time because start stress bigger, make the service life of laden equipment is reduced. Soft starter of the function of soft starter of 2 SIEMENS 3RW22 and characteristic flows to electric machinery report detect, control outputs voltage to be added to total pressure by certain linear, limitative excitation starts electric current, those who realize electric machinery is soft start, it has very strong interference rejection capability and control capacity, can avoid what suffer tall voltage and strong electron in the job to disturb. Soft starter uses digital control to spark, constant electric current is in the soft process that start flowing quickly, avoided the impact to electrified wire netting, the electric current that start can be in according to the need of spot load 70 %Ue of 30 % ～ (Ue is rated voltage) inside limits successive and adjustable. Can undertake adjustment to soft starter parameter, obtain optimal torsion with the smallest electric current, soft starter is to be able to reduce mechanical stress to the advantage of mechanical respect, prolong electromotor and accessary and mechanical service life. The time that start can have set according to different load, optimal to starting time to undertake optimize, inside this time limits, electromotor rotate speed is slow rise, have be short of, three-phase is lopsided, overload, flow too those who wait for electric machinery is all-around protection. Sexual price is compared tall, the operation is simple, volume is minor, weight is light, installation is debugged convenient, have overheat of silicon controlled rectifier and overvoltage protection. 2.

The 1 problem that before using soft starter, facilities exists joins make friends factory cold cut machine use (star / trigonometry) changeover starts plant. The mill that join press hard against each other is cold the flywheel heavy load that cuts machine place area, big diameter, be being started and jockey in the process inertial big, switch instant appears aiguille of tall electric current, the impulse current when electromotor is being started also brings very big impact to wave motion of voltage of electrified wire netting, produce very big harm to controlling device at the same time, often burn contactor, need often undertakes changing, affect production badly. Those who join make friends factory is cold cut machine when start occurrence breakdown can cause all fronts stop production. If increase distribution size to start electric machinery merely, cannot take apparently. Traditional step-down is started not from go up at all solve a problem. 2.

The 2 soft starter that after transforming, use start soft starter is a kind of collect soft start, soft jockey, carry gently energy-saving and muti_function protection controls equipment at the electric machinery of an organic whole. Implementation does not have concussion in the whole process that start and start electric machinery smoothly, and can adjust according to the character of electromotor load all sorts of parameter in the process that start, wait like the current limliting value, time that start. Just concern 2 times when 3 jobs principle and the Ma of the torsion that start that moving characteristic three-phase communicates asynchronous electromotor increase tension with place directly, that is to say, the tension that should reduce terminal of electric machinery wiring to go up only can affect these values (see a picture 1) . Soft started working principle is to pass control to string together receive what turn over canal of shunt-wound brilliant brake at power source and the three-phase between electric machinery be accusinged to guide current flow angle makes the terminal voltage of electric machinery from beforehand the cost of set rises to rated voltage (see a picture 2) . Nextpage3.

1 soft the started main way that start (1) voltage double brae is started (see a picture 3) , having startinging in becoming, increase and increase what output pitching moment to follow tension of electric machinery, an Us of initiative the voltage that start is offerred when start, the size with Us laden basis is adjustable, us tone arrives be more than moment of force of laden static friction, produce the optimal character that start. Output voltage to begin to rise by certain slope from Us at this moment, electric machinery is quickened ceaselessly. When output voltage is achieved amount to fast voltage Ur, electric machinery reachs rated rotate speed basically also. Soft starter detects automatically in the process that start amount to fast voltage, when electric machinery reachs rated rotate speed, make output voltage to achieve rated voltage. (2) does current limliting start: ?  of  of stern of natrium of  of fade chasm black denounces Xing bend so as to breakstubborn to defeat Da of Si of Gan stern  to conceive archives of ㄖ of   Zan  of graceful whetstoning stern wrings Miao of Bao of Su of Guan of be good at F to tick off overstep one's authority of lever of beautiful of Yong Chong  to grow permanent teeth? knows to output electric current to achieve beforehand the electric current of set is restricted to be worth Im, maintain I of output electric current next<Lift gradually below the condition of Im voltage, till rated voltage, make electric machinery rotate speed lifts gradually, reach rated rotate speed. The mill that join press hard against each other is cold cutting what the soft starter with useful machine uses is current limliting start, in reducing traditional pattern there is the very big long electricity that start in the process that start, starting the bypass contactor that soft starter disconnects when the voltage that start achieves rated voltage. The advantage of this kind of means that start is the electric current that start small, and can adjust by need. Small to influence of electrified wire netting, its defect is know to open dynamic pressure to fall hard when start, cannot make full use of pressure fall space. (3) dash forward jump start (see a picture 4) : ? ? of Ji Zhui of stern   makes brilliant brake canal complete inside cutty time guide after connecting rapid fall after a rise, this time can undertake linear rises artificially modulatory pressing the value of former set again, enter constant current to start, should start a method to apply to burden and need to overcome the starting situation of attrition. 4 soft all sorts of application circumstances that motor of started applied circumstance asynchronous altogethers not to need timing can be used, apply to all sorts of fan kind laden, need is soft start with soft jockey. Laden to the change operating mode, electromotor is in light convey by vehicles for a long time to go, only short when or the instant is in full load to run a circumstance, apply soft starter (do not take bypass contactor) have record energy-saving result gently. 5 last words pass the characteristic that understands 3RW22 of Xi Menzi soft starter and performance characteristics, in the use of the factory that join press hard against each other and traditional step-down the equipment that start undertakes comparative, because traditional control method exists in a few special situations inherent weakness, already cannot satisfy the need of modern convenience, so choice intelligence electromotor starts equipment soft starter, will be certain development way. CNC Milling CNC Machining