Probleme cu motoare

[Vizitator simona91]

Buna Am nevoie de ajutor cu urmatoarele probleme de electrotehnica.in caz ca ma poate ajuta cineva, i as fi foarte recunoscatoare. Multumesc1) On the rating plate of an electrical motor, following information is given: 220/400V 50Hz How shall this motor be connected to a supply voltage of 400V? A Star connected B Delta connected C I will write an email to ask my Dutch colleague’s to solve this problem. Clarification:………………2) On the rating plate of a three phase electric motor, following information is given: Voltage 220/380V, cos phi 0.9, efficiency 0.97, Power 100 kW What will the motor current be at a motor supply voltage of 380V/50Hz?A 169 AB 174 AC 301 AClarification mandatory:……………3) What is the current in the rotor bars at a squirrel cage motor in no load condition? A Equal to the nominal motor current; B Almost zero; C About 30% of the nominal motor current. Clarification:…………………4) In a crane installation a motor is running in a “2 Quadrant Control” configuration. What will happen at the asynchronous motor on lowering the load? A The motor will dissipate the released energy of the load as heat inside the motor; B The motor will consume current to ‘hold’ the load; C The motor will generate energy which will flow back into the electric drive system. Clarification:………

[costinium6]

pune intrebarile in limba romana.la prima intrebare motorul trebuie sa mearga in stea pentru ca in delta vor fi 220 pe bobinela a doua se calculeaza radical de 3, 1.73x400vx ila 3 este cla restul nu inteleg