To solve the problem of oil leakage

 1, product improvement: for porcelain set of oil leakage at the bottom of the transformer, because of the maintenance condition, can only be replaced with a new transformer. Will oil leakage transformer permanent magnet motor to return factory repair, and ask the manufacturer to improve the sealing structure. The transformer oil leakage, timely communication with the manufacturer recommended manufacturers choose better quality rubber motor magnet gasket, explore the possibility of using new material packing. 2, the process of making the maintenance plan for now a terminal oil leakage transformer by Taiwan to apply for stop service, timely deal with oil leakage. For found no oil leakage transformer maintenance plan, equipment stop service with a porcelain on the surface of the flange bolt fastening. During the overhaul of random overhaul of main transformer transformer terminal change once a gasket. 3, the pass of maintenance process: in the transformer overhaul the repair technology to the health of equipment has a decisive role. 

Pass of maintenance technique, in case for overhaul quality caused by defective equipment: such as wiring fever caused by poor contact, non-standard oil caused by false oil level and test unqualified, the bad weather caused insulation be affected with damp be affected with damp. In the concrete work of this notice. In particular, when a terminal assembly, porcelain set of inner arc bakelite pad should be paid attention to in installation surface must with porcelain set wall stick take, otherwise will lead to a terminal external after fastening flange surface tilt, make rubber gasket cannot even tighten and easy broken porcelain bushing. 4, product selection, now wholesalemotor.blogspot.com know, a growing number of oil-immersed transformer is replaced by SF6 transformers, the use of SF6 transformer can reduce many make the electrical motor 24v daily maintenance work, the only worry is leak problem, now understand of SF6 transformer leakage rate in a few parts per thousand, but now the oil-immersed transformer oil leakage rate in percentage more than a dozen, even a few decades. I think that using SF6 transformers very much worth considering.

Classification of ac motor

1,according to the working power supply classification:depending on the motor working power supply,can be divided into direct current motor and ac motor.Which ac motor is also divided into single-phase motor and three-phase motor. single phase generator 2,according to the structure and working principle of classification:motor according to the structure and working principle can be divided into small electric motors asynchronous motor and synchronous motor.Synchronous motor can also be divided into permanent magnet synchronous motor,synchronous motor and magnetic resistance motor with hysteresis.Asynchronous motor can be divided into ac induction motor and motor commutator.Induction motor is divided into three phase asynchronous motor,single-phase asynchronous motor and cover pole asynchronous motor.Communication is divided into single-phase series motor commutator motor,ac/dc motors and repulsion motor. 3,according to the classification of start-up and operation mode:the motor according to the start-up and operation mode can be divided www.dongfeng-motor.com into capacitor start motor,capacitor contributed to motor,capacitor start motor running and split-phase motors. 

4,according to the rotor structure classification:according to the structure of the rotor can be divided into the cage induction motor (old standard called squirrel-cage asynchronous motor) and wound rotor induction motor (wound asynchronous motor is called old standard). 5,according to the speed of classification:can be divided into the high speed motor,motor at low speed,constant speed motor and speed regulating motor.Has general is series of brush type ac motor,commonly used in small electric tools,such as some electric hair dryer,hand electric drill,the vacuum cleaner...Work with electric spark,noise is very big,but small size,large torque.Startup capacitor is used to produce to split phase of electrical motor single-phase ac power supply,using capacitor capacitive reactance of alternating current (ac),and after a coil in series,the overall current phase shift than simple inductor current phase shift,which USES two different phase current,the magnetic field to produce a different time,such as three-phase alternating current (ac),form a rotating magnetic field.

Sealing material and structure of the current transformer

1, the seal induction motor material Now the oil-immersed capacitive current transformer the sealing surface adopt oil resistant rubber gasket. Oil resistant rubber gasket performance: compression rate is 25% to 30%, at 130 ℃ when the inflation rate was 4%, and 50 ℃ when the shrinkage rate of 2.4%. According to the statistical data of the leakage of oil caused by gasket quality accounted for about 70% of the total oil leakage rate of above. Choose qualified rubber gasket, to eliminate leakage of transformer oil has a key role, of course it needs to communicate with transformer manufacturers. 2, the structure of the seal Transformer metal expander was adopted to realize full sealed, expander oil temperature changes when the volume of the compensation effect. In order to ensure the sealing surface fully tighten, do not lead to overly compressed seal again, most parts of limit seal. But in porcelain bushing www.facebook.com/dongfeng.motor and tank, metal expander coupling seal face and a outlet seal face of flange connection. Parts from the scene found that 400v ac motor motor vehicle the leakage of oil, it is precisely the flange surface is the most easy to oil leakage. So the flange face seal assembly procedure and process is particularly important. Good flange sealing surface must be smooth sealing surface cleaning, the pressure appropriate, reliable positioning, flange surface parallel uniform.

The analysis of the causes of leakage of transformer oil - to solve the problem of oil leakage

1,product improvement:for porcelain set of oil leakage at the bottom of the transformer,because of the maintenance condition,can only be replaced with a new transformer.Will oil leakage transformer to return factory repair,and ask the manufacturer to improve the sealing structure.The transformer oil leakage,timely communication with the manufacturer recommended manufacturers choose better quality rubber gasket,explore the possibility of using new material packing.2,the process of making the maintenance plan for now a terminal oil leakage transformer by Taiwan to asynchronous motor apply for stop service,timely deal with oil leakage.For found no oil leakage transformer maintenance plan,equipment stop service with a porcelain on the surface of the flange bolt fastening.During the overhaul of random overhaul of main transformer transformer terminal change once motor parts a gasket.3,the pass of maintenance process:in the transformer overhaul the repair technology to the health of equipment has a decisive role.

Pass of maintenance technique,in case for overhaul quality caused by defective equipment:such as wiring fever caused by poor contact,non-standard oil caused by false oil level and test unqualified,the bad weather caused insulation be affected with damp be affected with damp.In the concrete work of this www.facebook.com/dongfeng.motor notice.In particular,when a terminal assembly,porcelain set of inner arc bakelite pad should be paid attention to in installation surface must with porcelain set wall stick take,otherwise will lead to a terminal external after fastening flange surface tilt,make rubber gasket cannot even tighten and easy broken porcelain bushing.4,product selection,now know,a growing number of oil-immersed transformer is replaced by SF6 transformers,the use of SF6 transformer can reduce many electrical motor 24v make the daily maintenance work,the only worry is leak problem,now understand of SF6 transformer leakage rate in a few parts per thousand,but now the oil-immersed transformer oil leakage rate in percentage more than a dozen,even a few decades.I think that using SF6 transformers very much worth considering.

The structure of three phase asynchronous motor

A,the classification of the three-phase asynchronous motor:Classification:according to the rotor structure Category:squirrel-cage motor and wound rotor motor According to the protection type Categories:open (IP11),protected (IP22 and IP23),closed (IP44),explosion-proof According to the ventilation cooling way Categories:self-cooled,since fan cooled,he fan cooled,pipes,ventilated According to ac synchronous motor the installation structure Categories:horizontal,vertical foot,flange According to the grades of insulation Category:E,B,F,H, According to the work quota Category:continuous,intermittent,intermittent Description:Open (IP11) :cheaper price,the best cooling conditions,due to the rotor windings and exposed to air,can only be used for dry,little dust and no corrosive and explosive gas environment.Protected (IP22 and IP23) :ventilation cooling condition is good,also can prevent the water droplets and iron filings,sundry fall into motor internal,applies only to a few dry and dust and no corrosive and explosive gas environment.Enclosed (IP44) :suitable for damp,dusty,vulnerable to wind and rain erosion,corrosive gases,such as the poor working rotor and stator environment,the most common applications.

Second,the structure of the three-phase asynchronous motor (a) of the stator (static) 1,the stator core Part of motor magnetic circuit,and placed on the stator winding.Structure:the stator iron core by 0.35 ~ 0.5 mm thick surface is commonly insulating layer of silicon steel sheet coining,overlying and become,within the core of the circle has a uniform distribution trough,which embedded in the stator winding.Trough the stator core has the following kinds:Semi-closed type slot:frequency conversion motor efficiency and power factor is higher,but the winding wire and insulation are more difficult.Commonly used in low-voltage motor.Half-open mouth slot:can put molding winding embedded,commonly used in large and medium-sized low-voltage motors.The so-called forming the windings can be treated with insulation in advance and then into the slot.Open rack slot:to put molding winding embedded,insulation method is convenient,mainly used in high voltage motor.2,the stator winding Access is the circuit part of the motor,three-phase alternating current (ac),to produce a rotating magnetic field.Structure:by the three in the space between 120 ° Angle,said arrangement can be connected with the same structure of the winding,the winding of the coil respectively according to certain rule embedded in the stator slot.The main of the stator winding insulation project has the following three:(guarantee between the conductive part of the winding and iron core and reliable insulation and reliable insulation between the winding itself) (1) of insulation:overall between the stator core and stator winding insulation.(2) and white insulation:insulation between each phase of the stator winding.(3) the turn-to-turn insulation:each phase of the stator winding turn-to-turn insulation each wire.

The inverter no-load current is greater than the load current

A 75 kw micro can WIN - G9 inverter commissioning the strange phenomenon.Thank the factory technical personnel's guidance: load permanent magnet motor commissioning ah,why can't load motor magnet of commissioning.But since the first encounter this situation,the abnormal current,the light that is not to run at full speed.More can't load.Always want to find out why ah.Always thought that this is abnormal frequency converter.After the inverter running from the scene back,are still groping for the problem. Of repair a large power station zero line current,the harmonic component in line.Is the harmonic current.In no load or light www.facebook.com/guohong.trading carriage,the station in the output of the inverter circuit,whether there is a great deal of harmonic component? The harmonic component to come from? 


The measured result is true or not? Analysis of reasons for no-load caused large harmonic component in output current.Reasons of the harmonic current may have the following two reasons: 1,the inverter output PWM wave is not ideal,modulation mode fails to reach the best.In the software fails to reach the optimization control ways (new type of machine have definitely improved); 2,when no load,equivalent to the power capacity serious don't match with the single phase electric motor load capacity,power supply capacity is much greater than the converter capacity,this is a big reason of harmonic current.While carrying row,capacity matching conditions improve,harmonic component is greatly reduced.The synthesis of the two kinds of reasons,the old electrician are stumped me ah.For me,in the commissioning,I made a mistake in empirical ah,I was tied up in proportion to the input,output,current problem,almost had to surrender.

Capacitor start motor

 In capacitor start motor,start capacitance and start winding string together,thus forming a LC circuit,the circuit has good phase shift (and thus have a very good starting torque).The resistance for the motor will also increase the cost.Fixed phase capacitor motor Another motor is fixed phase capacitor (PSC) motor (i.e.,capacitor motor) up and running.This kind of motor operation mode is similar to the capacitor start motor described above,but it does not have the centrifugal switch,so its secondary winding is connected to the grid.PSC motor is usually used in hair dryer,electric fans,blowers,and other need to change.Under the condition of invariable load by changing www.dongfeng-motor.com the running winding signal to achieve the purpose of make the motor run at different speeds.All six winding connection respectively,a three-phase motor can connect two winding together through the rest of the a winding capacitance connected to start winding to run into one capacitor start motor.The repulsion motor Repulsion motor is single-phase ac motor rotor winding,it is similar to ac/dc motor.In the repulsion motor armature with brush nipple rather than and in series with the magnetic field.

Already have a few kinds of repulsion motor into production use,but most of all,with repulsion start sensing (RS)-IR motor operation.RS-IR motor with a centrifugal switch all the short commutator connect together,so when it is up to full speed it will run in the form of induction induction motor sales motor.RS-IR was used in the motor under low temperature and low voltage per ampere provide large starting torque.In 2005,almost did not sell any type of repulsion motors.Single-phase ac synchronous motor Small single-phase motor can also be designed to be magnetized rotor.This does not require any motor in the rotor induction motor,so they will not be lower than the main frequency.Instead,they will be as the rotation frequency synchronization.Because of their high speed precision,this kind of motor is typically used in electric power mechanical clock,record machine and tape recorder; They are also used in such as ribbon machine and telescope driving mechanism requires precise time of equipment.Shaded pole type synchronous motor is one of them.Because of inertia,so it is difficult to the rotor from state stopped immediately accelerated to synchronous speed.This kind of motor usually need some special way to start.A variety generator rotor and stator of different Design with a small induction motor (it will share the same and the synchronous motor excitation coil and rotor) or one-way speed (guarantee the rotor startup positive speed) as the very light of the rotor.

The difference between the speed reducer and frequency converter speed control Electrical engineers

Through the difference between the speed reducer and frequency converter speed control of mechanical devices often need to adjust the speed of three-phase asynchronous motor,often use reducer adjustment change frequency reduction ratio or transducer to adjust the speed of the motor. But by what is the difference between the speed reducer and frequency converter speed control? Together (see electrical engineer) to take us to get to know it.Reducer speed:Reducer is through mechanical transmission device to reduce the motor (motor) speed,such as common gear deceleration,turbine worm reducer,etc.Through the reducer to adjust the speed of the motor general need to make sure the following information:1,the types and specifications of the motor,speed,power (or torque),starting characteristics,short-term overload capacity,the moment of inertia,etc.

2,the types of mechanical work,specifications,purpose,rotational speed and power (or torque). Working system: constant load or changing load,variable load load diagram; Rev.,braking and short-time overload torque,start frequency; Shock and vibration levels; Direction of rotation,motor and reducer coupling way,whether the shaft extension with radial force and axial force.3,installation type (reducer and motor,the relative position of working machine,vertical and horizontal).4,transmission ratio and the margin of error.5,environmental temperature,air velocity,dust concentration and environmental conditions such as ph value; (if there is a circulating lubrication and cooling conditions,lubrication station) and the limitation on the vibration and noise.6,to the degree of service life,Motor vehicle safety and reliability requirements.7,the requirement for the size and weight.8,the demands induction motor price of operation and control.9,the source of material,blank,standard parts and inventory.10,on volume,cost and price requirements.

11 and delivery term.Frequency converter speed control:Inverter is by changing the frequency of alternating current motor (motor) in order to achieve the purpose of speed regulation. Reduce the motor speed by the frequency converter,you can achieve the goal of energy saving. But generally within 0-50 hz frequency conversion motor to realize the constant torque speed control,within the scope of 50-100 hz to realize constant power speed regulation,and stepless speed regulation,wide speed range.To sum up,through the difference between the speed reducer and frequency converter speed control is mainly: reducer speed a wider range of speed (slow),but generally not stepless speed regulation,speed regulating motor after a lot of physical and electrical parameters can be continued,in addition to the speed loss; And use frequency converter speed control can realize stepless speed regulation,but limited range of speed (only within 3 -- 100 hz speed),speed when affected by a lot of electric parameters,and can't guarantee the original motor of the number of parameters,and fever more serious.

Motor delta connection,the following two configurations

 Switch from star to triangle,motor delta connection,the following two configurations:W2 U2 V2,V2 W2 U2 As the motor magnetic generator terminal box standard outlet on the left.According to the FUJI company motor into current,two configurations have difference.Is there any difference between a connection?1,as long as you connect the power cord three position unchanged,such as L1,L2,L3 and U1,V1,W1 connected to the same,so the two configurations of the triangle and the y connection,is a steering,will not reverse;2,as long as you change the position of three power cords,or changing the phase sequence,then the two configurations of the triangle and the y connection,will reverse at the same time;

3,in the Y-delta start wholesalemotor.blogspot.com main circuit,as long as you don't change the position of the three power cord connection such as L1,L2,L3 and U1,V1,respectively connected W1 phase sequence is changeless,then Y-delta start,switching process will not reverse!The season reference aromatic content of the reply:The results of the two methods is to remain unchanged. Will do. From the analysis I see two kinds of connection,the current in the coil is the first start with the runtime of the same. The second is the opposite,but the direction of rotation of the magnetic field is the same. Instantaneous polarity is opposite.Don't know will make 8500w gasoline generator much difference.

Motor common faults

 Common faults of three phase asynchronous motor are swept rotor chamber,vibration,winding turns or short circuit between the layers,winding grounding,stator winding lack of phase operation,the reverse of the stator winding unbalanced three phase current,core silicon steel sheet insulation damage,etc.Motor vibration generated when the noise and the additional load,may be bad driving device,can also be caused by the motor itself,such as the rotor dynamic balance is not good,shaft bending,installation does not reach the designated position,loose fasteners and so on.Motor open phase running the cause of the main line fuse is melt fuse or current setting values are not appropriate,touch switch contacts caused by the bad.If you run a long time,will burn out motor.Three-phase voltage imbalance or winding electric vehicle motor interturn short circuit will cause unbalanced three phase current,the stator winding end reverse connection will cause the motor temperature rise,winding grounding or short circuit can cause too much electricity,iron core silicon steel sheet insulation damage will cause motor overheating,etc.

In a word,in actual operation,to analyze the cause of the problem correctly,strengthen the patrol and maintenance,timely discover and eliminate the malfunction of the motor,as much as possible to ensure safe operation of motor Motor maintenance of motor start,first check the motor assembly is flexible,winding insulation resistance is in line with the requirements,the rotating part for jam,also check the motor start and protection equipment eligibility requirements,such as motor grounding device is in good condition,the selected low voltage circuit breaker,contactor,fuse configuration is correct,and so on.Motor start,start times cannot too much,otherwise the motor could overheat burn out.In the operation of the motor,to closely monitor the voltage,current and temperature,the motor operating electricalmotor1.blogspot.com voltage should be strictly controlled within the scope of the change,otherwise may cause motor overheating,also,the current is not too high or too low,because when the voltage must be,running current drag,it reflects the motor load,mechanical load,motor overload operation for a long time,the current will rise,make serious motor overheating,if the motor load is light,the formation of "big horse car",the motor capacity is not able to make full use of.In daily maintenance,also should closely monitor any abnormal noise or vibration motor,check whether the screw is fall off or loose,the motor repair and maintenance regularly,keep clear of the external dust,oil change on a regular basis.

The selection of the motor selection of motor,first of all to understand the mechanical load characteristics of the motor,according to the types and features of the mechanical load to select the rated capacity,rated speed and rated voltage of the motor and the pattern.For a production machine equipped with an electric motor,the first thing to reasonably choose the power of the motor.Usually according to the need of the production of mechanical load to select the power of the motor,at the same time,consider the work of load problem,that is to say,should be adapted to the selected motor mechanical load of the continuous nature of work,short-term or intermittent cycle.When the power to choose not too big,also not too small.Choose the small,can't guarantee the normal work of the motor and production machinery; Choose the big,motor fan although can guarantee the normal operation,but not the economy,motor capacity can not be make full use of,and motor often cannot full load operation,make the efficiency and power factor is not high.Secondly,according to the request of power supply voltage conditions,chooses Y series three-phase asynchronous motor rated voltage and frequency with the power supply voltage and frequency.The speed of the motor must be selected according to the requirement of the production machinery nameplate,otherwise may change in the production of mechanical performance.In addition,the structure,protection,cooling of the motor and installation form,should adapt to the requirement of using the environment conditions,and to strive for installation,debugging,maintenance is convenient,safe and reliable to ensure the motor can run.

The inverter from what respect to protection on the motor

Abstract:the frequency converter is widely used in various industries,mainly due to its energy saving and the function of the frequency control of motor speed in the working condition of equipment and system application,the frequency converter from what respect to the protection of motor? Tags:frequency control,frequency converter,motor,energy-saving frequency converter is widely applied in industry control engineering net all rights reserved,mainly due to its energy saving and the function of the frequency control of motor speed in the working condition of equipment and system application,so the inverter is from what respect to the protection of motor? Below we will analyze this problem solve.Frequency converter for motor protection mainly has the following several aspects:over voltage protection,low voltage protection,over current protection,open phase protection,reverse phase protection,overload protection,earthing protection,short circuit protection,overclocking protection and protection of the stall.Here are the several types of the frequency converter for motor protection method were introduced simply.1.The over voltage protection:the inverter output voltage detection function,frequency converter can automatically adjust the output voltage,the motor is not withstand overvoltage.

Even if the output voltage and output voltage adjustment by more rotor and stator than 110% of the normal voltage,electric motor cooling fan frequency converter can also through the outage protection for motor.2.The under voltage protection:when the voltage is less than 90% of the normal voltage of the motor,frequency converter to protect downtime.3.The over current protection:when the motor current by more than 150% of the rating / 3 seconds,or 200% of the rated current / 10 microseconds,frequency converter through the downtime to protect the motor.4.Open phase protection:monitoring the output voltage,when the output phase,frequency converter alarm,after a period of time frequency converter through the downtime to protect the motor.5.Reverse protection:frequency converter motor can only rotate along one direction,unable to set the direction of rotation,unless the user changes motor wiring A,B,C phase sequence,there is no reverse phase.6.Overload protection:monitoring frequency converter motor current,when the motor current is more than 120% of the rated current / 1 minute,the frequency converter via down to protect the motor.7.Grounding protection:frequency converter is equipped with special grounding protection circuit,generally made up of earthing protection of the transformer and relay,when a phase or two phase ground,inverter alarm.If the user requirements,of course,we can also design for the grounding protection immediately after downtime.

8.Short circuit protection:after the inverter output short circuit,inevitably cause over-current,within 10 microseconds inverter through down to protect the motor.9.Overclocking protection:frequency converter has a maximum and minimum frequency limit function,make the output frequency can only be within the prescribed scope,thus realizing the overclocking protection function.10.Stalling protection:general for synchronous motor stalling protection.For asynchronous motor CONTROL ENGINEERING China all rights reserved,accelerate the process of stall will be performance for current,frequency converter by over current and overload protection to realize the protection function.Reduction in the process of stall can be set in the process of debugging to avoid safety deceleration time.

High efficiency motor

Advantage:1,compared with the standard motor due to the higher efficiency value,thus can realize the energy saving effect;2,use the longer,the more obvious energy saving effect,economic effect is rotor cutting machine more significant;3,due to the adopted to reduce the loss of design,so the temperature rise is small,so as to realize long life,high reliability;4,high cost performance,wholesalemotor.blogspot.com can apply for government subsidies.And the difference between ordinary motor:1,rated high efficiency;2,high efficiency motor for the efficiency of the rated point also have corresponding requirements,within the scope of 25%~100% rated power efficiency ac geared motor should be satisfied The standards requirements;3,less efficient motor slip,that is to say,the speed will be slightly higher;4,efficient motor take measures from the design,material and process,such as adopting reasonable,rotor slot number,fan parameters and sine Measures,reduce the loss,the efficiency can be increased 220v ac electric motors by 2% - 8%,increased by 4% on average.

The structure and working principle of electromagnetic ac contactor

 The principle,selection and connection of ac contactor,ac contactor is widely used as the power of open circuit and control circuit.It use main contact to mini electric motor open and close circuit,to perform the control instruction with auxiliary contacts.Main contact usually only normally generator stator open contacts and auxiliary contacts often two to have often opened the function of normally closed contacts,small contactor is also often used as intermediate relay with main circuit.Ac contactor contact,made of silver tungsten alloy has good electrical conductivity and high temperature electric motors price erosion resistance.

Ac contactor has four main components:(1) the electromagnetic system,including attracting coil,moving iron core and static iron core;(2) the contact system,including three main contactor and two normally open,normally closed,auxiliary contacts,it is even with the moving iron core of linked together with each other;(3) wholesalemotor.blogspot.com arc extinguishing device,generally larger capacity of ac contactor has arc extinguishing device,in order to quickly cut off the electric arc,from burn out the main contactor;(4) insulation shell and accessories,all kinds of springs,transmission mechanism,short circuit ring,terminal,etc.

Submersible pump motor repair 10 points for attention

Mine submersible pump motor electromagnetic part and ordinary motor basic same,therefore,electromagnetic failure and repair,but due to the particularity of explosion-proof motor.In carries on the repair or reconstruction,it shall comply with the following provisions: The relevant personnel should understand,repair units and the relevant national laws and regulations,explosion-proof standards for repair work and the relevant provisions of the qualified products.Second,the unit should have for explosion-proof motor repair process equipment and the necessary inspection and test apparatus.Before three,maintenance,should prepare the necessary technical data.Four,commissioning before the motor repair,check the cable entry,relay protection and wiring system,to ensure that the company is still in good condition and conform to the requirement of explosion protection.Five,to engage in explosion-proof motor maintenance personnel should undertake the necessary training.After six,after inspection and acceptance of the inspection items,is made by authorization of the explosion-proof test unit or recognition,can be in repair units; 

Think it is necessary to project still explosion-proof test unit by explosion-proof inspection unit.After repair,explosion-proof motor should be to use the department to provide the following documents: 1) fault inspection;2) repair work instructions;3) Motor vehicle replacement and repair parts catalog;4) inspection and test results;5) repair certificate.Eight,are not allowed to repair the piano pieces 1) by the size of glass,plastic or other unstable parts made of materials;2) fasteners;3) the manufacturer or explosion-proof code that can't repair parts,such as encapsulation component.A sign of nine,after the repair will not affect the explosion-proof performance of repair,after repair without repair.Ten,the flame-proof certification after after repair motor repair the repair unit inspection department shall issue certificate of approval.Described above shall include at least by repairing the name,type,specification,water pump explosion-proof motor logo,the name of the class units and its approval certificate number,explosion-proof certificate number,date of repair,etc.The standard code for GB3836.13-1997 after the repair.Signs must be norm,durable,and resistant to chemical corrosion.Signs should be metal materials,commonly permanently fixed on the motor after the repair,repair again,after repair,the previous repair sign shall be removed.

The classification of ac contactor purposes

 Contactor is a kind of automation control of electrical appliances.Contactor is mainly used for frequent connected or diplomatic acmotortrading.blogspot.com relations,dc,has a large capacity of control,remote operation,relay can realize timing operation and interlock control,all kinds of quantitative control and the pressure loss and under-voltage protection,widely used in automatic control circuit,the main control object is motor,can also be used to control other electric power load,such as electric heaters,lighting,electric welder,capacitor Banks,etc.Contactor can be divided by accused of www.dongfeng- motor.com current type ac contactor and dc contactor.Here introduces the commonly used ac contactor.Communication can be divided into the electromagnetic contactor and vacuum type electric motors price two kinds.Model shows that:(1) the above model for the standard model,in recent years,the new developed B series ac contactor,its ac electric motor model for BXX.(2) electromagnetic ac contactor ware for CJ.Vacuum type ac contactor ware for CZ.

The working principle of the ac contactor

Electromagnetic suction when energized coil,the static iron core,will be moving iron core and,as a result of the contact system is with the linkage of moving iron core,so core to drive three move contact run at the single phase electric motor same time,the contact closure,and connected to the power supply.Disappear when power coil,suction,moving iron core linkage part rely on spring reaction and separation,make the main contactor disconnect,cut off power supply.The choice of ac contactor:(1) the continuous operation of equipment.Contactor calculate by 67-75%.The 100 - a ac contactor,can control the maximum rated current is 67-75 - a the following equipment.(2) uninterrupted operation of equipment.Contactor calculate by 80%.The 100 - a ac contactor,can only control the maximum rated current is 80 a the following equipment.(3) and short- time working equipment.Contactor calculate by 116-120%.


The 100 a ac contactor,can only control the maximum rated current is below 116-120 - a device.Consider the work environment electric motors 12 volt and the structure of contactor.Also shows that:as the market competition is intense,to reduce the cost of domestic some manufacturer,has been in the corners,for example:in the coil production reduce wire diameter less number of turns around,even in touch head is not in conformity with the national standard of the material or thickness and the cross section is not ac electric motors enough.This kind of circumstance is not only reflected in the contactor,on top of other products such as short as well.Cause in be used actually,mark is 100 a contactor or short circuit,the actual load can only be even lower in 80 a,high failure rate.Popular theory is:so,now have to use domestic low-end products,to the rated capacity of 7 discount according to the www.facebook.com/dongfeng.motor nameplate instruction to use!

Measuring rotor winding connection is wrong use method of failure

 Put the rotor under small electric fan motor test in a test in the mouth,use the turn-to-turn short circuit tester electricity,tester within the closed magnetic circuit core and rotor core has alternating magnetic flux.Multimeter is 10 v ac voltage profile,wholesalemotor.blogspot.com adjacent commutator segment and commutator segment,every piece of commutator segment,every two pieces of commutator segment,every three to every more pieces commutator segment between the voltage value.Rotor winding connection correct voltage size should electricalmotor1.blogspot.com be consistent,if you have below normal,it is possible that some components lead to reverse,with the fault of rotor winding to repair to meet again. "Little experience" Described above with a multimeter ac 10 v voltage profile measuring voltage between adjacent the commutator segment,as there are below normal,should turn the rotor position,and then look at the voltage value,so as high efficiency electric motor to avoid miscalculation.If still below normal,should be cleaned of mica slot commutator conductive material (such as charcoal powder),then test again,in order to avoid miscalculation.

Rated current of the three-phase ac motor is calculated

Rated current In = Pn/(1.732 * cos phi n * Un acmotortrading.blogspot.com eta).Type of Pn for the nominal power rating,the Un as the rated voltage,cos phi n as the rated power factor,eta rated electric motors 12 volt operating efficiency.Note that the power refers to the output shaft power,Pn/eta is the electrical power input.3 power rating =),rated voltage,rated current,efficiency,5kw permanent magnet generator power factor,the apparent power = rated voltage,rated current,apparent power is equal to mini electric motor the vector and active power and reactive power,power rating is refers to the mechanical output at rated power.

Main technical parameters and combination switch selection

According to the combination switch model for more technical parameters,combination switch performance of main technical parameters are 1) the rated voltage of rated voltage is refers to under prescribed conditions,switch in the long-term work under high voltage. 2) electric motor 12v 500w rated current rated current is refers to under generator stator prescribed conditions,the switch in the closing position allowed by the maximum working current for a long time. 3) on and off On-off ability under prescribed conditions,can reliably connected under rated voltage and breaking the maximum current value. 4) mechanical life Refers to the need to repair or replacement under the mechanical parts of no load operation.

5) electric life means under the mini electric motor condition of the normal work of the regulations,does not require repair or replacement parts,the number of times the load operation.Combination switch used for isolating switch,the rated current shall be the is less than the sum of the load current in isolating circuit; Used to wholesalemotor.blogspot.com control the motor,the rated current generally take 1.5 ~ 2.5 times rated current of the motor. Shall be determined according to actual needs in the electrical control circuit,the connection mode of automobile combination switch,correct selection to meet the requirements of wiring combination switch specification.

The difference between motor and brushless motors

From now in general use in the industry,there are two main types of motor:efficient rare earth permanent magnet has a motor and the efficient rare earth permanent magnet brushless motor on the market at present most Electric bicycle is still stay in brush motor stage.A brush motor using mechanical commutation,the technical requirements of the control system is low,relative cost is lower than the brushless motor,A brush motor starting torque slightly larger than the brushless motor. But
the fatal weakness is:life is short,large noise and low efficiency.Long-term use of carbon brush wear serious,it is easy to damage.At the same time wear produced huge amounts of carbon dust,These dust fall in gear oil,gear oil accelerate dries up,the motor noise further increased.A brush motor use to within a year or so will need to replace carbon brush,You will find a charge mileage bought less than two-thirds,and climbing when power is insufficient,will burn out the controller.This is because the motor After the replacement of carbon brush and commutator also be ground out a groove,reduce carbon brush contact area,poor contact of carbon brush after electrify which sparks and accelerate oxidation in electricalmotor1.blogspot.com To implement and copper,acmotortrading.blogspot.com lead to the undesirable phenomenon.

Brushless motor electronic commutation replace the mechanical commutation,technically superior to brush motor.Because of brushless motor without gear or gear,the motor,reduce wear and tear The unreliability.Its efficiency within a certain range of current ratio has a brush motor with high efficiency.Brushless motor driving up almost no motor lamination noise,and for up to 10 years to life On.According to the comparison,both brushless motor is better than have a brush.At present,there have been some electric bicycle factory with motor is to switch to the original brushless electric Machine.Brushless motor must be the development direction of electric bicycle. Consumers can come up from appearance to identify motor belongs to "brush" or "no brush" :first,"brushless electric wire" eight root,and the "brush" electric wire to the positive and negative There are two root;Secondly,with the induction motor hand when the drive motor,before and after the brushless motor rotation is easy,and before the "brush" motors turn easily,after when transfer is quite tight.

The machine after the installation commissioning,if found e.numerical,vibration more than should which to play?

(1),the rotor balance not nuclear good;(2),rotor balance quickly loose;(3),a shaft bending deformation;(4),the coupling center not nuclear is;(5),bottom screw loose;6,installation foundation uneven or solid.(1),magnet prices grease brand not appropriate;(2),grease quality is not good or bad;(3),grease in the bearing chamber,too little or too much;(4),grease with sundry; (5),the rotation part and stationary part;6,bearing inner ring or outer ring;All landowners,bearing
type is wrong,or the electric motors 12 volt quality is bad;Today,of the coupling;Pet-name ruby,belt pull too tight;

Attending,motor vibration is too large.Motor rotor in the process of production,due to the influence of various factors (such as uneven material casting porosity and shrinkage cavity,parts of the weight of ac electric motors error and machining error,etc.) will cause the imbalance of rotor in weight,so the rotor in the assembly after the completion of the school to balance.More than six pole or rated speed is 1000 RPM the motor and motor) under its rotor can be only static balance,balance the other motor www.facebook.com/dongfeng.motor rotor to the school.

The dc grounding method

A independent grounding:as discussed above the needs of the grounding part,each independently set up their own grounding system,the grounding method,called independent grounding.It has the advantage of not cause mutual interference between each system,it is especially important for communication system.But the network is liable to be struck by lightning bad,so in addition to is in danger of explosion proof requirements must adopt independent way of lightning protection of the environment,generally do not adopt the way of independent grounding.This independent grounding in the 60 s and seventy s before use is more,now replaced by common ground.Second,common ground:also called unified wholesalemotor.blogspot.com grounding.

It is unified all the need for grounding system receives a grounding device,or the original

grounding device each system through underground or on the ground with a metal conductor

connected,make them ac electric motorsbecome smooth electrical grounding network,between the grounding method for common ground.Common grounding is currently the most widely used.Three,one-point earthing:each system grounding line connects to ground strap the same point or the same metal plane,one-point earthing method can solve the potential ac alternators 220v problems such as ground wire of each system,so can reduce the degree of interference between each system,especially the electric motors price 50 hz power frequency signal to eliminate interference on the system basically,so a little grounding method is widely used in engineering.A little grounding eliminates common impedance coupling and low frequency interference caused by ground loop.Can work well in more than 1 MHZ and frequency,when the size of the whole system is small (maximum size less than 20,l/l for jamming signal wavelength) can be applied to the 10 MHZ.

Cascade speed regulation method

Cascade speed regulation refers to the motor rotor winding circuit in series motor vehicle spare partswith adjustable additional potential to change the slip of the motor,to achieve the purpose of speed control.Most of the slip power is absorbed by series of additional potential to recycle produce additional device,the absorption of 12 volt electric motor returning the slip power grid or conversion of energy use.According to the slip power utilization way,cascade speed regulation can be divided wholesalemotor.blogspot.com into motor cascade speed regulation,mechanical cascade speed regulation and thyristor cascade speed regulation form,adopts thyristor cascade speed regulation electrical motor Its characteristic is: to speed the slip loss in the process of feedback to the grid or production machinery,high efficiency;Installed capacity is proportional to the speed range,the investment province,apply to speed range in production machinery from 70% to 90% of the rated speed;Speed regulating device failure can switch to run at full speed,avoid production;Thyristor cascade speed regulating power factor is low,the influence on harmonic.This method is suitable for the fan,water pump and the rolling mill,mine hoist,the extrusion machine use.