Frequency conversion air conditioning inverter motherboard power supply

Y series totally enclosed protect Asynchronous motor
Specifications
1. 20 years manufacturing experience 
2. 12 months guarantee 
3. low noise and temperature rise 
4. high starting torque 

5. AC Voltage: 220V/380V, 380V/660V,400V/690V,220V/400V

Air-conditioning outdoor mainboard work power supplied with switching power supply, motherboard + 12 v and + 5 v power supply circuit. Mainly generator set spare parts for outdoor electrical relay (led outdoor power supply is no longer PTC but straight), fan control relay, four-way valve control relay to motor parts provide power supply. The main working voltage for outdoor CPU. Therefore, wholesalemotor.blogspot.com only the frequency conversion lamination power circuit of switching power supply work, to make the control of outdoor work, can maintain normal CPU communication between inside and outside the machine.

Sensorless brushless dc motor control - a back emf method

 AC induction cooling fan motor 
Specifications
1. Customised 
2. good quality 
3. 20 years manufacturing experience 
4. Altitude: ≤1000m

Assume that during the T T 1 0 ~ G5, G6 conduction, dangling a photograph, as shown in figure 1 (a), is a phase back emf ea = U an (a) phase voltage phase, a phase voltage U ag = U + U ng = an ea + U ng. At t0 time, ea = 0, b and c two phase current, on the other hand, and that the impedance is equal, and by the small diesel generator back emf waveform is known: the eb + ec = 0, so U ng = 1/2 U d, so U ag = ea + U ng = 1/2 U d. As long as it can detect or U an U d (U ag - 1/2) of the zero point, can be indirectly detect the zero moment of ea. Because the testing point ahead of the next converter 30 °, can be after 1/12 inverter cycle delay, shut off the G5, trigger conduction G1, which can ensure the maximum average electromagnetic torque motor can continuously produce. Repeat the above process, detection of ea in turn another zero and eb, ec all zero, and also delay, in turn trigger conduction of generator set spare parts a, b, c three-phase bridge arm up and down, to ensure the correctness of the permanent magnet brushless dc motor reversing sequence. According to different detection objects, and the detection method can respectively called phase voltage method (test U an), the terminal voltage method (U ag). 


 electric motor 20hp aluminum body 

Specifications
1. 20 years manufacturing experience 
2. competitive price,high quality 

3. Brand Name: FUJIAN DONGFENG MACHINERY ELECTRICAL LIABILITY CO., LTD

Among them, the terminal voltage method, the application of more. In terminal voltage method, in order to realize the phase voltage of zero crossing detection, first U ag, U can be the bg, U CG input low pass filtering devices, respectively, in order to eliminate the can seriously interfere with the back emf waveform, that there is no clear chopper signals passing zero [4]. And then use www.facebook.com/dongfeng.motor a voltage comparator, respectively each phase voltage compared to zero level, according to the comparison results of coding signal encoding, to get the rotor position signal. At present, the selection of zero level as shown in figure 2 [2], mostly by V, V b, V c three-phase symmetric star connection level V 0 instead of the center of the resistance of the circuit. Abroad recently put forward a new method: the three opposite electric potential (replace) with phase voltage first by square wave into a balanced three-phase sine wave, again through the star connection, get the central level, instead of a zero level. This method can get accurate "0" (zero after balanced three-phase sine wave synthesis), can reduce the position detection error.

Troubleshoot general steps - symptoms analysis

 Symptom analysis electric motors price is for all possible information about fault original state is collected and judgment process.Before the fault indications interference,for all the information should be carefully analyzed.The original information in general can be obtained from the following aspects:1.Ask for details of equipment failure phenomenon to operators.By asking for equipment use and situation before and after the change motor magnet process,damage or failure of information,also can learn some similar past failure phenomenon,reasons and have measures,etc.Operators may sometimes because of other reasons,not willing to or can't put all the plot clearly.Maintenance personnel should be analysis to distinguish ability and enough patience,to get the real original information as much as possible.2.Observe and preliminary examination.By watching heard touch,check whether such as cracking,noise,odors,overheating and other special phenomenon.

Observation of the equipment to conduct a comprehensive tend to get valuable clues.Work station of the content of the preliminary examination including detection device (light,display and alarm information,etc.),check the position of the switch,and operation control mechanism,adjusting device and the signal device,etc.3.Sure,in the absence of any dangerous electric test.Normally according to normal operating procedures www.facebook.com/dongfeng.motor shall require the operator to boot device.If the fault is not the whole machine of the electrical control system paralysis,can adopt the method of test run to start the equipment,help a comprehensive maintenance personnel for fault state of the original impression.Some electrical fault can be by hand,eye,nose,ear,use the means such as see hear touch,directly perceived failure equipment abnormal temperature rise,vibration,odor,noise,etc.,of the equipment fault can be located.The electrical motor 24v purpose of this phase is to collect the fault of the original information,so that to the current actual situation analysis,and to derive the most possible fault area of clues,check reference as the next step.But be careful not to sign according to the imprecise or not sufficient information to judge prematurely.

What maintenance electrician to specific professional skills

A door technology can foothold in society.Maintenance electrician belongs to technical professionals,our country is lack of senior technicians,if electric motor 12v 500w you learn good,also is very promising in the future.Main master electrician: maintenance electrician knowledge and basic skills,indoor wiring installation,grounding device installation and maintenance,repair and maintenance of common transformer,disassembling and maintenance of various commonly used motor,commonly used low voltage apparatus and distribution equipment installation and maintenance,motor control circuit basic installation and maintenance,commonly used machine tools installation and maintenance of electrical wiring,electronic circuit installation and debugging,acmotortrading.blogspot.com electrical control circuit design,programmable power electric motors controller and its application.As to hard to learn,the key see yourself don't work hard,go for it,have confidence in myself,should be able to learn well.

Combination switch with low voltage circuit breaker recognition application

Appliances that can signal or request according to the outside world, manually or automatically switched on or off circuit, the circuit parameter, intermittent or continuous change to switch circuit or single phase induction motor non-electric object, control, protection, detection and adjustment of electrical devices or equipment. Low voltage electrical appliances are usually refers to working in the rated ac voltage up to 1200 v or dc voltage below 1500 v circuit of electrical appliances. Low voltage apparatus single phase generator according to the basic use commonly divided into two categories, distribution appliances and control electronics. Distribution appliances mainly include the combination switch, low voltage circuit breaker, fuse, transformer; Control appliances including contactor, relay and the main electrical appliances (including the button, trip switch, switch). 

Low voltage electrical classification method: according to www.dongfeng-motor.com the operation mode can be divided into manual and automatic electrical appliances; According to the principle of work is divided into electromagnetic appliances and non-electricity control electronics; According to a non-contact divided into contact electrical appliances, non-contact electric and hybrid electric appliance; According to the electrical configuration is divided into a single electrical appliances and complete set www.facebook.com/dongfeng.motors of electrical appliances; Industrial electrical appliances, chemical by using occasions are divided into general electric, mine electrical, traction electric appliance, aviation, Marine, electrical appliances, etc. Combination, combination switch. Switch is often used as a switch, but also in the electrical control circuit used as isolating switch, not frequently switched on and points out the role of electrical control circuit.

The choice of single-phase capacitor electric mechanical and electrical capacity

The choice of single-phase capacitor small electric fan motor electric mechanical and electrical capacity Most of single-phase motor capacitor,such acmotor2.blogspot.com as washing machines,electric fans,submersible pump,small woodworking planer,etc.But due to capacitor spoiled or improper selection capacity,Motor running temperature,noise,power consumption increases,the speed is reduced,the phenomenon such as torque decreases,here the selection of electrical and mechanical capacity of the capacitor motor approach to electricity Work friends can do a introduction,for your reference. Calculation method 1:Single-phase capacitor electric mechanical and electrical capacity depends on the size of the deputy winding current.

Because of different sizes,single phase motor power to consider when choosing capacitance rev Dynamic torque,speed,temperature,noise and loss should be within the normal range.So first of all should from the nameplate detect single-phase motor power,calculate the primary winding of the electricity Flow,and then according to the primary winding current (0.5 0.7) times to perkins diesel generator setcalculate the current value of each winding current,according to the formula C = IC * 10 divided by 2 PI fVo.The formula of the I I = P = V is obtained. 2: the selection of capacitor Single-phase capacitor motor should first choose oil-immersed capacitor,pressure value should be above 400 v.Second optional www.facebook.com/guohong.trading ac

electrolytic capacitor,its small size,low prices,but life Life is a bit short.

Motor temperature rise too high or winding burned

The number of positive &negative too ordinary,often make the motor work under launch condition,often cause temperature rise too high,and even burn winding.Common three phase induction motor reasons: being driven mechanical acmotortrading.blogspot.com card master,ambient temperature is too high,the belt too loose or too tight,the electromagnetic part of fault,the power supply voltage is too high,too low,the gap between the end of the motor coil and single phase capacitor start induction motor iron core vent plug,220v acelectric motors fan leaf damage,etc.

General electrical engineer to summarize the influence of frequency converter for motor

1 the efficiency of the motor and the problem of temperature rise In either in the form of a

frequency converter, both in the operation of the different degree of harmonic voltage and current,

make the motor in non-sinusoidal voltage, power flow operation. At the current widespread use of sine wave type PWM inverter as an example, the basic is zero, the low-order harmonic larger than the rest of the 220v electric motor carrier frequency times the left and right sides of

higher harmonic components as: 2 u + 1 (u for modulation ratio). Can lead to higher harmonic motor stator copper loss, rotor copper loss, iron loss and the increase of the additional loss, the most significant is the rotor copper loss; For asynchronous motor is close to the base wave frequency corresponds to the synchronous speed of rotation, therefore, higher harmonic voltage to a larger slip cutting rotor after conducting bar, will produce very big rotor loss; In addition, also should be considered because of skin effect produced by the additional copper loss. These losses will make motor extra heat, low efficiency, output power decreases, and such as ordinary motor running in the inverter output non-sinusoidal power supply conditions, the general temperature will increase 10% to 20%. 

2 motor insulation strength problem At present middle and small converter, many are using the

PWM control mode. It's about several thousand to more than 10 KHZ carrier frequency, which makes the

motor stator winding to withstand high voltage build-up rate, equivalent to impose great impulse

voltage gradient on motor, the motor of the turn-to-turn insulation withstand more ordeal. In

addition, the rectangular produced by PWM inverter chopper superposition of impulse voltage on the

motor operating voltage, which not only high peak and the high frequency impulse voltage, would pose

a threat to the electric motor 12v 500w insulation of the motor, to ground

insulation under the repeated impact of high pressure can accelerate ageing. 3 harmonic

electromagnetic noise and vibration Ordinary motor using frequency inverter power supply, can make the electromagnetic, mechanical, ventilation and other factors caused by the vibration and noise

becomes more complicated. Frequency conversion power harmonic and motor electromagnetic part contains all of the time the inherent space harmonic interference each other and form all kinds of

electromagnetic vibration force. When the electromagnetic wave frequency and motor of the body's natural vibration frequency is consistent or close to, will produce resonance phenomenon, so as to increase the noise. Due to the motor operating frequency range wide, wide speed change range, all

kinds of the electromagnetic wave frequency is difficult to avoid the components of the motor of the

inherent vibration frequency. 

Four shaft voltage increase Shaft voltage refers ac motor to two axes voltage or voltage between shaft and shaft, for motor frequency conversion power supply, usually on each phase voltage on the motor is balanced, however, because each phase rectifier components and control components differences in features, may be a momentary voltage imbalance, produced in the shaft larger shaft voltage; Combined with the harmonic voltage on the rotor will be bearing oil film as medium to form a earth capacitance, producing a capacitive current; The current flows through the oil film between shaft and bush, if critical lubrication condition, the oil film will be destroyed, there will be a large current flows through the oil film, thus shortening bearing alloy, bearing life or damage to the accident. 5 motor for frequent starting and braking ability to adapt As a result of the inverter power supply, motor can under low frequency and voltage start, in the form of no impact current and frequency converter is available for braking modes of the brake quickly, create conditions for the realization of the frequent starting and braking, and the

mechanical system and electromagnetic system of the motor is in circulation under the action of

alternating force, brings to the mechanical structure and insulation structure fatigue and

accelerated aging problem. 6 low-speed cooling problems First of all, the impedance of the

asynchronous motor is not ideal, when power frequency is low, the power loss caused by high order

harmonic. Second, general motors in speed decreases, current and magnetic flux basic keep

inconvenience, but the cooling air volume and speed of three proportional to reduce, cause the low

speed of a motor cooling conditions deteriorate, a sharp increase in temperature is difficult to

realize the constant torque output. General electrical engineer pointed out that, in view of the

above issues ahead of protective 8500w gasoline generator measures to prolong the

service life of click.