显示标签为“220 volt ac electric motor”的博文。显示所有博文
显示标签为“220 volt ac electric motor”的博文。显示所有博文

2014年10月21日星期二

PLC control two pump start-up failure solutions to problems


Situation:in the double liang steam double-effect lithium bromide absorption air-conditioning unit,the use of omron PLC (PA204S C200HE-CPU42,power supply) to control the start of two pumps. When,in turn,start the two pumps,often led to the suspension of the power of the PLC,thus stop running program.Second,the detection of 1,use the meter to measure the voltage electric motor 12v 500w waveform of two pump ordinal startup PLC power PA204S ac voltage of the power supply change found:when did not start the electrical motor 12v 1000w pump,the voltage of the power supply is normal,when start the two pumps,instantaneous fell to the power supply voltage of 184 v,184 v and the duration of the above 25 ms,PLC to stop working,and to determine the effect of pump power of PLC.2,in order to solve this problem,respectively for the following tests: A) driving the pump first,delay around 10 s to start small pump,power supply voltage drop to about 190 v,the instructions first,pump makes instantaneous voltage drops,later start small pump,affect smaller,but it need to modify the PLC program.

B) because the pump power supply is turned by high tension line through a transformer,transformer capacity,can be considered a large capacity of transformer,may make the pump will be smaller influence on the PLC power supply voltage.C) in the PLC power supply termination a large capacitance,but the effect is not obvious.D) finally in one power supply transformer converted by a 220 v power supply to PLC,found that even in the start two pumps at the same time,PLC power supply voltage drop is only about 204 v,204 v,the can.Conclusion:as a result acmotortrading.blogspot.com of the PLC power supply is supplied with water pump in the same way,and the plant's transformer capacity is small,so in the start two pumps,caused the PLC power supply voltage drops below 85% of rated voltage,and duration of more than 10 ms,resulting in PLC detected power interruption,stop working. So the advice from the transformer converted one by one in the 220 v power to separate for PLC,which can solve the problem.

A 7.5 kw motor it is rated current of the 15 ma,if beyond 3 ma affect electricity opportunities?


The motor is driven by a small centrifugal pump,bearing also just changed,center also from the new correction,disintegration of pump is no defect,but there is always the phenomenon of fever and excessive current and motor magnet motor noise? Please some directions No-load current of the motor is 20-50% of rated current commonly,if too much no-load current should undertake the following check. 1 phase voltage of the motor parts stator winding is high 2 whether take star wiring fault into Angle 3 motor air gap is too big 4 internal wiring for error 5 stator windings wire diameter is too small,6 7 of electricalmotor1.blogspot.com the rotor iron core is neat assembly quality is unqualified,whether bearing lubrication good 8 core weight too small nine winding inside do you have any short circuit,open circuit or ground fault for you is wrong,but I'd give you the answer,the 7.5 KW motor is impossible to 15 ma of current,should be 15 Ann,you electrical motor 24v put the motor no-load test run first to measure current if current is disposed of in accordance with the method of the above,if the current normal pump you have any question.