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.

Machine tool equipment electrical troubleshooting - for appearance inspection fault area

In determining the scope of the possibility permanent magnet generator of failure,for within the scope of the electrical components and wires are appearance inspection,such as:the melt blown fuse;The location of the travel switch adjustment is not appropriate;Wire connector is loose or fall off;Contactor and relay contactor fall off or poor contact,coil burn 12v motor discoloring the burning surface electric motor insulation paper,flashing the insulating varnish outflow;Spring falls off or broken;Electrical switch,acmotortrading.blogspot.com etc.,the action mechanism of blocked failure can clearly show that point of failure.

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.

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 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, ac electric motor parts 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 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 motor fan 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.