How much is the no-load current of asynchronous motor?

 electric motor stator rotor lamination motor parts 
Specifications
1. Lamination of electric motor 
2. IP54 class F 
3. 100% copper 
4. silicon steel stamping 
5.stunning performance 
Asynchronous motor no-load running, the current in the three-phase winding of the stator, is called the no-load single phase motor current. Most of the no-load current is used to produce a rotating magnetic field, known as the no-load excitation current, no-load current reactive component. There is a small part of no-load current is used to produce all kinds of power loss during no-load running (such as friction, ventilation and core loss), the no-load current is a part of the active component, due to account for the proportion of small, negligible. Therefore, can think of is reactive current idle current. From this point of view, it is as small as possible, so that the ac motor prices power factor of the motor raised, the power supply is good.


high efficiency high power electric motor Y2 motor

Specifications
1. effiency: IE2 and IE1 
2. 20 years manufacturing experience 
3. 12 months guarantee 

4. low noise and vibtration
 If no load current is big, because of the stator winding conductors carrying area is certain, allowed through current is certain, allows for active current can reduce flows through a wire, the motor can drive the load will be reduced, the motor output is reduced, with too much load, winding would be easy to fever. But the no-load current also cannot too small, otherwise will affect the other performance of the motor. Generally the no- load current of the small motor Three phase motor is about 30% ~ 70% of rated current, the no-load current of the large and medium- sized motor is about 20% ~ 40% of rated current. What is specific to the no-load current of an electric motor, the motor nameplate or product manuals, generally not marked. Have electrician often need to know how much is this value, this value to judge the quality of the motor repair, can use.

The structure of the four-way reversing valve

Four-way reversing valve is mainly composed of pneumatic directional control valve spool (main) valve, electromagnetic directional valve (control valve) and capillary. Within the main wholesalemotor.blogspot.com valve is electric motor fan cover composed of slide block, piston valve core, the main valve body ends for hole can make both ends of the capillary and connect body space, slider respectively fixed on both ends with ac motor the pistons, piston on both sides of the space through the vent in the piston is same. Control valve consists of body and electromagnetic lamination coil. The body contains type needle valve core. Between the main valve and control valve has three (or four) capillary is linked together, form the whole four-way reversing valve.

Why low voltage winding of transformer in the inside,and high voltage winding in the outside?

The arrangement of the high and acmotor2.blogspot.com low voltage transformer,it is decided by many factors.But for most of the transformer,low level around the layout in the high voltage winding is put inside.This is mainly from the insulation into consideration.In theory,no matter how high or low voltage windings to decorate,can be variable pressure role.But because the iron core transformer is grounded,due to the single phase generator low voltage winding is close to the core,from the perspective of insulation easy to do.If the high voltage winding is close to the core,is due to the high voltage winding voltage is very high,to meet the insulation requirements,requires very of insulation materials and the insulation of the large distance.Such not only increases the volume of small electric motors the winding,and waste of the insulating material.Moreover,as a result of the transformer voltage regulation is electrical motor to rely on change of the high voltage winding tap,namely change the number of turns,so the high voltage winding is placed in the low voltage winding outside,lead more easily also.

Three-phase asynchronous motor winding fault analysis and processing

Winding short circuit Due to poor welding or use corrosive flux,have not cleared after welding,it may cause a pot of welding or loose;Subjected to mechanical stress or collision coil short circuit,also can make the wire burned,short circuit and earth fault in a couple of wire and burn a single or a few wire short circuit,several other wire due to the increase of current temperature rise,cause heating

winding and open circuit.Generally fall into one phase winding end disconnection,turn-to-turn short circuit,parallel branch circuit,wire and burn more of a single circuit,rotor broken cage.1.The fault phenomenon Motor can't start,three phase current balance,no abnormal noise or vibration,temperature rise more than permitted or smoke.2.The reason (1) during overhaul and maintenance touch off or manufacturing quality problems.,(2) winding each element (phase) group and the winding and fixture wire connection head welding,sealing off long running overheating.(3) by the mechanical force and electromagnetic force make winding damage or pulled apart or cause drag mark.(4) or interphase short circuit and grounding caused winding coils badly burned or fuse,etc.Methods to examine 

3.(1) the method of observation.Breakpoint most occurred in winding ends,look have without touch fold,joint the presence of desoldering.(2) a multimeter.Using resistance,to "Y" type of connection to connect a table bar in the center of the "Y" shape,the other in turn in the head end of the three-phase

winding,infinite phase has a breakpoint;"Delta" connection type of short connection,measuring winding in each group respectively,infinity to breaking point.www.dongfeng-motor.com (3) test lamp.Method with former,such as bright a photograph for open circuit.(4) megohmmeter.Resistance tends to infinity (that is,not as a zero value) is the cut-off point.(5) current meter method.Motor at runtime,use current meter to measure three phase current,if the imbalance of three phase current and short-circuit phenomenon,and no is a phase winding is part of the current small short circuit fault.(6) bridge method.A phase when the motor is bigger than the other two phase resistance,resistance show that the phase winding part of open circuit fault;

(7) ac geared motor the current balance method.For "Y" type of connection,but after the three-phase winding parallel,alternating current into the low voltage large current,if the current in the

three-phase winding is greater than 10%,one end of the small current for the circuit;For "delta"

connection type,the stator winding of a contact apart first,then by interlinked into low voltage high

current,one of the small current for open circuit.ac motor wind generator (8) broken cage detector

test.Check,if the broken rotor cage millivoltmeter readings should be reduced.4.Open circuit

processing method (1) the opening in the end,the connection after welded,the package on insulation

materials,set on the insulation tube,good binding,dry again.(2) the winding due to interturn,interphase short circuit and grounding,etc and cause severe charred generally should change new windings.(3) to the breaking point in the slot,belong to a few breakpoints for emergency treatment,the grouping elimination method is adopted to find the breakpoint,and broken in winding connection and the insulation used after 220v ac electric motors qualified.(4) can be used for broken squirrel-cage rotor cage welding,cold connection or change the original repair.

Motor can't start

1,motor does not turn and there is no sound: more than two phase or two phase power or winding circuit,first check the power supply voltage,if the balance of three-phase voltage,then fault in the motor itself,can detect the resistance of the three-phase winding of single phase capacitor start induction motor the motor,to find out the wire diesel generator winding.And 2,the motor does not turn but hum: measuring the motor terminal,if the balance of three phase voltage and rated voltage value,can judgment is serious overload,check the steps of: first take

the load,then the speed of the motor with a normal voice,which can determine overload or load

malfunction with the mechanical parts,if still won't turn,twist of the hand motor shaft are

available,and if it is tight or motionless,and three phase current,if the three phase current balance,but larger than the rating,the mechanical part of the motor was stuck,may lack of oil motor,bearing rust,or was badly damaged and end cover or oil cover too oblique,rotor and bore a collision sweep (bore) when turn the motor shaft by hand to feel struggled with a certain way or heard diesel generator periodically wiping,the chamber can be judged to sweep.

3,,the motor speed slowly and have a buzz: this kind of failure of shaft cooperates,if measured one phase current is zero,while the other two phase current is far higher than the rated current,that is two phase operation,and the reason is: circuit or power supply circuit,a phase or a motor winding

circuit. Whether the small capacity of the motor can be measured with a multimeter direct on and off. Medium capacity motor use much more due to winding wire and around many branch in parallel,which if broken several root or disconnect a parallel branch check up more troublesome,when such a situation usually adopts the method of phase current balance or resistance method. Use a bridge measuring the resistance of the three-phase winding resistance method,such as three-phase resistance percentage www.dongfeng-motor.com difference five above,a phase for breaking phase resistance is larger.