The output frequency

The output frequency is describe the car power output voltage frequency.We use mains is alternating current (ac),frequency of permanent magnet generator 50 hz,so we want to car power electrical motor can also provide the same frequency of alternating current (ac),the current general car power can meet the demand,that is to say,the output motor run capacitor frequency is 50 hz.The same as the output voltage,output frequency will fluctuate within a certain scope,the range as small as possible,the range in practical use is in commonly 0.1 Hz.In addition some special car power output is the electricalmotor1.blogspot.com direct current,output frequency is zero,so the car power of generally used for special purposes,such as notebook car power dedicated to a certain type of notebook.

Multimeter application technique measure skills

1,the road test diode,transistor,voltage regulator tube is good or bad,because in the actual circuit,bias resistors or diode triode,voltage regulator tube peripheral resistance is compared commonly big,mostly over hundreds of thousands of ohm,in this way,we can use the multimeter R * 10 Ω or R electricalmotor1.blogspot.com 1 Ω shift to measure the p-n junction of the road. In road measurement,measurement in R x 10 Ω gears p-n junction should have a clear direction,features (if the positive and negative to the resistance differs not quite apparent,can convert R x 1 Ω file to test),generally positive resistance at R x 10 Ω file whose hands should be instructed in about 200 Ω,time measurement motor run capacitor in R x 1 Ω file whose hands should be indicated when measuring around 30 Ω (according to different phenotypes may differ ac electric motor slightly). 

Forward resistance is too big or reverse measurement results if the value is too small,suggests that the p-n junction has a problem,the tube also have a problem. This method was especially effective for maintenance,can very quickly find out bad tube,even has not been fully broken can be detected but bad tubes. For example,when you use small resistance profile measurement is a PN junction resistance is ac induction motor too large,if you put it down with the commonly used welding Ω R x 1 k file and test,may be normal,in fact,the characteristics of the tube has gone bad,cannot work normally or unstable.2,measuring resistance: it is important to choose the right range,when the pointer instructions from 1/3 to 2/3 full scale measurement precision is highest,the most accurate. Note that in R x 10 k ohms resistance measured level of resistance values,not to fingers on both ends of the resistance,so that the body resistance will make small measurement results.

Voltage current transformer model meaning

Capacitive voltage transformer (CVT),in 1970 developed the domestic first 330 KVCVT,1980 and 1985,developed fan motor the first generation and second acmotortrading.blogspot.com generation KVCVT 500,1990 and 1995,developed the third and fourth generation KVCVT 500,more than 30 years has accumulated rich 12 volt electric motor experience in scientific research,development,design and production,in the domestic developed generation after generation of CVT new products,three phase induction motor giving impetus to the development of the domestic CVT.CVT's main features are: 1.High electric strength,insulation margin is large,reliable operation.2.Reliable damping ferroresonance.Successful adoption of the new group phase,with strict quality control,ensure that the factory's every piece of CVT are under any of the voltage from low to high effective damping various ferromagnetic resonance frequency.3.Good contact response characteristics.When the second time remaining after a short circuit voltage can fall below 5% in 20 ms,especially adapted to the fast relay protection.4.Has the power grid harmonic monitoring of patent technology.

Troubleshoot general steps - equipment inspection

According to the symptoms of the analysis permanent magnet motor of the preliminary conclusion and doubt,more detailed inspections of equipment,especially those who is considered the most possible fault zone.Attention should be paid to this stage should try to avoid unnecessary disassembly of permanent magnet generator equipment,to prevent more failure caused by the operation of the indiscretion.Don't adjust control device,because under normal circumstances,the fault parameters will hide blindly and symptoms has not been ruled out,but also with the development of the fault and make the symptoms appear,and may even cause more wholesalemotor.blogspot.com serious failure.So,fans motor must avoid blindness,prevent complicate fault for not careful operation,to avoid causing confusion symptoms instead,extend the time of troubleshooting.

The role of the current transformer is used to measure the larger current

Current transformer is a kind of current commutation device,symbols for CT.Its role is to put the large current into a small current,supply measuring instrument and relay the current chart,indirect measurement by large wholesalemotor.blogspot.com current.But also can isolate high voltage,to ensure the safety of staff and secondary equipment.Current transformer secondary side current is 5 Why can't a current transformer secondary side circuit? Current transformer secondary side is not allowed to open operation.In the current transformer secondary coil on the instrument coil impedance is small,the equivalent of running in the secondary coil short- circuit condition.Transformer secondary coil terminal voltage on only a few volts.Of the magnetic flux in core is motor vehicle very small.Although primary coil magnetomotive force can reach hundreds or thousands of Ann ampere-turns or larger.But most were established by short circuit secondary coil demagnetization magnetomotive force offset,only a small fraction of excitation magnetomotive force as the core to establish a magnetic flux in the core.

If in running the diesel generating secondary coil disconnection,vice side current is equal to zero,then the demagnetization effect of magnetomotive force disappears,and the original edge of magnetomotive force is constant,the original edge measured current all become excitation current,this will make the iron core of sharp,magnetic flux core severe fever that burn out the coil insulation,or make the high side of short circuit.Other secondary coil open out the high voltage is induced,it is very dangerous for instrument and operators so current transformer secondary side is not allowed to disconnect. Why can't a voltage transformer secondary side short circuit? If the short circuit in the operation of the secondary 220v ac electric motors side of voltage transformer,secondary coil impedance decrease greatly,can appear a lot of short circuit current,make the secondary coil burned due to severe fever.So in the operation of the transformer are not allowed to short circuit.General voltage transformer secondary side with a fuse.Only transformer of 35 kv and below,on the high side have a fuse when transformer short-circuit the purpose is to put it cut off from the high voltage circuit

The classification of electrical fault

According to the composition characteristics of electrical devices,from looking for electrical fault,from the viewpoint of the common electrical fault can be divided into three categories: 1.The power failure: lack of power,voltage,frequency deviation,the polarity of by phase line and neutral line and reverse,the lack of a power supply,phase sequence change,ac/dc mixed.2.The circuit fault: break,electric vehicle motor short circuit,short,grounding,connection error.3.The equipment and component failure: overheating burned,can not run,electrical breakdown,performance becomes worse.According to the fault phenomena analysis the cause of the problem,the key is to find electrical fault.Is based on the analysis of the basic theory of electrician,is for the electrical device structure,principle,performance,fully understand,ac electric motor is with the combination of the actual fault.


The causes of an electrical fault may be a lot of,it is important to find out the main reason in many reasons,and use approach to troubleshooting.For example,a three- phase cage asynchronous motor fault functioning,whatever the case,is the most concentrated performance motor does not work,but is not necessarily in the motor fault,and may be a power failure,may also be the failure of circuit or equipment and components.That is to say,the same failure form,failure of a variety of reasons.In these reasons,which is what reasons make the motor can't work,even after a deeper and more detailed analysis.For example: if the motor is used for acmotortrading.blogspot.com the first time,it should check power supply,circuit,the motor and load analysis; If the motor is used for the first time after repair,it should start from the motor itself check analysis; If the motor is running for a period of time suddenly can't run,it should check points off power supply and control components.Through the above process,then determine the specific cause of motor fault.

Repair and matters needing attention

After find out the fault point electrical equipment,will start to repair,commissioning,records,etc.,and then consign is used,but must pay attention to the following: (1) find out the fault point and permanent magnet generatorrepair failure,can't find the fault points should be paid attention to as a search for the end of electrical motor the fault must be further find out the root cause of the failure analysis.(2) find out the fault point,must according to different fault condition and the location corresponding to the correct

repair method.(3) in the motor run capacitor repair work of fault point,under normal circumstances should try to be recovered.(4) electrical fault repair finished,need electricity commissioning,cooperate with the operator,to avoid new failures.(5) after each troubleshooting,electricalmotor1.blogspot.com should be

timely sum up experience,and make the maintenance records.Records include: industrial machinery

model,name,number,the date of the failure,failure phenomena,parts,damage of electric appliance,the

cause of the problem,after the repair measures and repair operation,etc.Record purpose: as a file as

a reference for future maintenance,and through the analysis of all previous failures,take the

corresponding effective measures to prevent similar accidents from happening again or improvements

for the design of the electric equipment itself,etc.