The Thermorresistors

The devices called thermoresistors are temperature sensors, in which the principle of performance is based on a property, of some components capable of varying the electrical resistance with an expressive variation of temperature. These sensors have a calibrated resistance that can be modified in a linear way in relation to their temperature, guaranteeing a continuous monitoring of the motor heating procedure, by a display of the controller with a high degree of sensitivity and return precision.

This sensor can also act as an alarm, a process that can happen outside the common working temperature, and shutdown, which is usually set to a higher temperature of the insulation class. The resistances of the contacts, cables, as well as other devices, can intervene in the mediation. Several types of configurations can be found, generated in the quest to reduce these results.      5mm pitch gates

The two-wire configuration is often analyzed sufficiently, in environments where the length of the sensor cable to the instrument can not exceed the maximum limit. In the configuration of three wires, the most used by industries, there is a compensation of the electrical resistance by the third wire.


The effects of the harmonics generated by the drive may affect the operation, life and performance of the electric motor. These effects can be divided into three categories, heating, dielectric and mechanical. Current harmonics are additional to the fundamental current, therefore generating additional heat in the motor windings. Even a 30 percent (30 percent) value of current distortion in an engine generates no more than 8 percent (8 percent) of additional heat, because of motor windings that behave like a filter. The drive supplier must supply the engine supplier with information on the harmonics generated to allow the engine to be properly designed with the correct heat dissipation / absorption capacity to counterbalance any additional loss and / or heating.

An electric motor operating at variable speed through a frequency inverter must meet the same temperature rise limits as a pure sine wave motor. Current harmonics may result in a higher emission of audible noise. The motors shall verify that the noise level limit is adhered to when they are driven by static frequency inverters. The harmonics also contribute to the pulsating torque.

Insulating devices with thermal principles

Bimetal type protectors with normally closed contacts are widely used mainly in the case of single-phase induction motors, in order to protect against overheating caused by overloads, causing the rotor to be blocked, as well as possible voltage drops. Thus, thermal elements are normally applied to electric motors of the three-phase type, although their application only becomes feasible in motors with Y-connection. The advantages to be highlighted are the combination of current-sensitive protector, as well as temperature .

However, it should be noted that a disadvantage is that the current is limited by the protector being directly connected to the coil of the single-phase motor hammond power. The thermal protector is basically composed of a bimetallic disc, which has two moving contacts, plus a resistance and a pair of fixed contacts. Thus, the protectors are driven in series and due to the thermal dissipation, which is caused by the passage of the current, through the internal resistance, a deformation of the disc can occur, resulting in the opening of the contacts and thus causing the motor power is interrupted. After a lower than specified temperature has been reached, this protector must be reconnected.

Induced Current

It is important to say that the duly induced current in the sneeze is responsible for allowing the flow that will surely cross it, will suffer a considerable delay in the case of being compared to the flow of the part that will not be embraced by it. This whole process can result in a very similar way to a rotating field, which has the ability to move in exactly the direction of the part that is not hugged to the embraced part of the pole, producing conjugate, which will be able to make the engine until it reaches the nominal speed.

However, distorted field motors, which can also be known as shaded pole motors, can be distinguished among different categories of single-phase induction motors, for a number of factors, such as presenting their most reliable, simple starting process it’s cheap. Three distinct types of this motor can be found, such as that of protruding poles, also considered as distributed skeleton and winding. One of the most common ways to be found on the market is that of outgoing poles. It is possible to observe that a part of each pole, which can vary in average of 25% to 35% of the same, in short circuit is surrounded by a copper turn.

Using the Connection Cables

In order to ensure the proper performance of some specific applications, such as submersible pumps, it is imperative that the cable is chemically resistant to the pump oil. In this way, the flexible pipes have as their main function, to adequately isolate and cover electrically the welds of the connections between the connecting cable, the coil wires and other wires.

To ensure that they can mold to the weld points and lashing of the coil head, the tubes need to be flexible. In electric motors mrosupply flexo, three types of tubes are used, the heat shrinkable polyester tube, the polyester weave tube coated with acrylic resin, and the glass fiber tube coated with silicone rubber.

The connecting cables must be properly designed from specific materials, elastomeric insulation. It is necessary to emphasize that they always need to be of the same thermal class as the motor. These materials have a great electrical resistance, which together with the adequate flexibility, allows simple handling to occur in the course of processes of extreme importance, such as manufacturing, maintenance and installation of the motor, for example.

Principles of Faraday’s Law

It is possible to say that among the scientists who contributed to the experiments on the connection between electricity and magnetism was the Englishman Michael Faraday. Born near London, he was both physicist and chemist, although he had a weak theoretical background. Therefore, he valued experiences as evidence of natural phenomena. Faraday filled with mercury a conducting metal, formed by two bowls, so that it had an electric wire coming out of its bottom. In one of them, he fixed a magnetized bar vertically and in the other, he loosened another magneto.

In the first cup, the moment the electric wire hung above hers touched the mercury, closing the circuit, it began to spin around the magnet. In the other cup, where the wire was loose, at the moment it was connected to the current, the magnet revolved around the central wire. So this was the first electric-type engine mrosupply motors, the authentic ancestor of the machines designed today. Some time later, Faraday was able to conclude that if he placed a magnet inside a coil, in which the wire passed electric power, it would move along the lines of force.

Synchronous Generator Concepts

The generator has elements extremely relevant to its operation in a suitable way, such as the rotor, referring to the rotating part of the machine. It can consist of a package of sheets of ferromagnetic material held in a winding formed by copper conductors, called field winding, with the function of generating a constant magnetic field, in the same way as in the case of the direct current generator to interact with the field produced by the stator winding.

It is important to note that its synchronous name is due to the fact that this machine is capable of operating with a constant speed of rotation synchronized with the frequency of the alternating electric voltage applied to its terminals. This means that, due to the rotational movement between the rotating field and the rotor, it is known as a synchronous machine, since it must be taken into account that it promotes synchronism between the stator and rotor fields. In this way, this generator is considered one of the most important types of rotary electric machines, allowing the conversion of energy when operated as a generator or as a motor.


Smooth Polo Rotor

Plain-rotor rotors are identified by having a uniform cylindrical shape and bundle of unsegmented, single-piece or laser-cut plates, usually attached to the shaft by “ribs”. The poles are constructed by grouping the sheet of the package and therefore are integral with the package of plates of the rotor and are not detachable. The field coils are constructed of insulated copper wires and secured in grooves of the sheet pack, with coil configuration being allocated without turning the poles at the periphery of the rotor. The bobbin heads are fastened by means of bandage or shaped steel sleeve on the coils.

The cage of this type of rotor is also symmetrically distributed. This rotor composition exhibits high symmetry, masses evenly distributed over the entire length of the rotor, making it cylindrical, compact and robust. Due to these peculiarities the synchronous motors with smooth poles rotor are most often used in machines of high rotation. Due to this rotor fabrication, the air gap is almost constant throughout the rotor circumference, with possible paths for equivalent magnetic flux through the interpolar regions, where there are also plates, which allows greater flow dispersion.

Electromechanical Phenomena

Most electric motors fulfill their functions through the interaction between electromagnetic fields, however, it should be emphasized that there are other types of motors based on different electromechanical phenomena, such as electrostatic forces, for example.

The fundamental idea in which electromagnetic motors are idealized is that there is a mechanical force across the wire at the moment the electric current is being driven if it is immersed in a magnetic field. The force is described basically in the law of Lorentz force, being perpendicular to the wire and also to the magnetic field.

When it is a rotating motor, there is a rotating element, consisting of the rotor, responsible for performing the rotation by the wires and the magnetic field arranged so that a torque is developed on the rotor center line.

It can be said that most of the magnetic machines are rotating, but there are also linear types. If the motor is rotating, the rotatable part is called the rotor, and the stationary part, the stator part. Briefly, the motor is composed primarily of electromagnets installed in grooves of the ferromagnetic material, which make up the rotor body.


Magnetism basically consists of lines considered impossible to be seen of forces created by types of natural magnets and also by the known as electromagnet.

Among the most common types of natural magnets, the three main ones are the needle found in the compass, the horseshoe used in animals, and the bar. The magnets have two main specifications, they can attract and attach to any material containing iron, and if they are free to move, such as the compass needle, for example, have the ability to point to the north or south.

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In electric motors, each magnet has two poles, one is the north pole and the other is the south pole. The lines impossible to be seen in the magnetic flux leave the north pole and go towards the south pole. Just as the flow lines are invisible, the effects of the magnetic field created by them, depending on the situation, may even become visible.

If a sheet of paper is placed on a natural magnet or an electromagnet, and iron filings are placed on it, the iron filings may be deposited along the invisible lines of the stream.

Motors with and without grease

In greaseless electric motors, lubrication must be performed as described in the existing preventive maintenance plan. The disassembly and assembly of this type of motor must be made according to the specifications described by the manufacturer. Electric motors with shielded bearings require their bearings to be automatically replaced when they reach the end of their grease life.

In the case of motors with grease fittings, at the precise moment of relubrication of their bearings with the engine stopped, it is necessary to thoroughly clean the vicinity of the grease entry holes. It is extremely important that approximately half of the recommended total grease is placed on the nameplate of the engine, and thus cause the engine to rotate for about one minute at the rated speed.

The engine must be switched off so that the remaining grease can be put in place and, afterwards, replace the grease guard. For the relubrication process of the bearings at the moment the engine is in operation, it is important that the person responsible for the action is careful to clean the vicinity of the grease entry hole and, as in electric motors without grease.

Insulation Materials and Systems

The electric induction motor is a simple and robust construction machine and its durability depends almost exclusively on the durability of the winding insulation. This is altered by many factors such as vibrations, humidity and corrosive environments, among others. Among these factors, the most significant is the temperature supported by the insulating materials used.

The increase of eight to ten degrees above the thermal class limit of the insulation temperature, allows the reduction of the winding durability by half. For longer durability, the use of thermal sensors is recommended for retention of the winding.

At the moment we mention the decrease of the durability of the motor, it is not referring to the high temperatures, when the insulation burns and the winding is suddenly destroyed. The durability of the insulation refers to the gradual aging of the insulation, which over time becomes dry, losing its insulating action until it can no longer withstand the applied voltage and results in a short circuit.

Experience has shown that insulation has an almost unlimited duration if its temperature is kept below the limit of its thermal class. Above this limit, the insulation durability becomes shorter as the working temperature gets higher.


Induction Motor

The single-phase induction electric motor does not exhibit the peculiar rotating magnetic field of the three-phase motor; Thus, it has no starting torque. The inversion of the field in the stator stimulates a voltage in the rotor, which aligns with the stator field, however without starting torque.

Thus, an auxiliary starter is required so that the magnetic force formed between the stator and rotor fields begins to rotate and maintain its continuous speed. The split-phase motor is based on a simple principle, which can be clarified as follows: when inserting a single-phase AC power in two windings in parallel but 90 ° lagged, designated main and starting, the magnetic field that Form produces a suitable starting conjugate to make the rotor move.

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This type of motor is used on machines with low torque, such as washing machines. When in the split-phase motor we insert a capacitor in series with the starting winding, the mismatch between the supply voltage and the starting winding current is changed, reaching approximately 90 °, resulting in an increase in torque.

Universal Engine – more info

The universal motor is a sturdy yet small electric motor, designed to be ideally suited for portable devices or mainly for home use. An engine with these purposes has its electrical scheme adapted to work with any type of available voltage.

The design and principle of operation of the universal motor are the same as those of the motor in series of DC: when the universal motor is powered by alternating current, the variation of the direction of the current causes variation in the field, both of the rotor and of the stator. In this way, the conjugate continues to rotate in the same initial direction, with no reversal of the direction of rotation.

A higher power universal electric motor can be obtained if modifications are made to your design so that it performs well with DC and AC.

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Advantages: low manufacturing cost when produced in large quantities; Speed ​​control according to the need of the application.

Disadvantages: high noise level, both audible and electromagnetic, which produces interference in electronic circuits; Short service life due to brush and switch wear; Are usually made for intermittent or sporadic (drill, blender, mixer), so do not support continuous work.

Application of Superconductors in Electric Motors

The application of superconductors in electric motors has been much studied for technical, economic reasons, and for reducing energy wastage.

The scientific studies for the use of new materials aim at reducing the costs, the weight and the dimensions of the machines by the application of magnetic fields larger than the conventional ones, since the commercial superconducting wires allow to have density of current much higher to the one used by the copper, Of the order of 15 to 20A / mm2.

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This density may appear low when compared to the current density of the superconductor itself, which currently reaches 500A / mm2, but unfortunately this immense density can not yet be fully exploited. This superconducting material still needs a mechanical holding precursor, such as a silver coating.

As for the number of poles in electric motors with superconductors, the magnetomotive force is not very influenced by the number of poles, but the greater number of poles the greater the superconducting material, and its cost. We can conclude that the lower the number of poles, the better it will be, since the volume of the superconductor will be smaller, besides having fewer connections.

Three Phase Induction Motors – Advantages

The basic feature of the three-phase induction electric motor (MIT) is to operate at a speed somewhat below the synchronous speed. And this speed is defined by the number of poles and the frequency of power.

MIT has a major drawback in that the direct current output is very high at about 10 times its rated current. The reason for this high current is the low value of its equivalent equivalent impedance at the start, which is sometimes less than its rated speed. When you just want to smooth the starting of the electric motor without changing its speed, the soft-starter electronic device must be used, so that the current is as low as possible.

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The advantages of the three-phase system over the single-phase system are:

– For the same size, three-phase generators and motors have higher power than single-phase motors;

– Three-phase transmission lines require less copper than single-phase transmission lines to carry the same power;

– Single-phase (other than collector) motors do not have their own starting; The three-phase can leave without outside assistance.

Multi-engine is a model airplane that needs to have more than one electric motor to operate

In most models it is known to connect a multi-motor it is necessary to make a connection considered simple between the battery, the esc and the receiver and thus everything will work.

When the model becomes more complex, many model aircraft find it difficult to know how all components should be connected. The model airplane considered complete are the multi-engines that are: the twin engine, the trimotor and the tetramotor.

The multi-engine is a model airplane that needs to have more than one electric motor to run. The electric motor is extremely practical for this type of model because the petrol or glow multimotors need to be regulated all electric equally with the same rotation. If the electric motor is not regulated correctly, this electric motor will work on all flights, so it is necessary to make a correct adjustment.

The electric motor need not evade the rule. Should be placed in the same rotation, otherwise the flight can be dangerous and unstable even more if subjected to large rotational differences.

Cooling causes the electric motor to last longer

Pleasure to surf. This is the main feature of the Mercury 3.3 HP 2T electric outboard motor, because both in and out of the water, this portable electric motor from Mercury Marine is unparalleled. As it has many other features, the electric motor is able to provide pleasure in navigation even over a long period.

This Mercury 3.3 HP 2T electric outboard motor comes equipped with an ignition system that is electronic, safe and also efficient. Thus, circular-load induction enables the outboard electric motor to operate smoothly and evenly regardless of navigability.

The cooling of the electric motor is responsible for making the motor last longer and makes less noise when operating. The multilayer paint, aluminum alloy and numerous stainless steel components ensure the electric motor protection against corrosion. best offers for coxreels

This model of electric motor has some accompanying items that are: the tank is incorporated, also comes a set of tools and also the circuit breaker.

Electric motor in promotions

Whenever we are going to buy any product, it is very common for us to think about economics, especially since today it is very common to worry about more affordable values, which makes a big difference in our final income for the month. When it comes to electric motor can not be different, the customer who wishes to purchase that machine has to analyze prices in different companies.

The companies that work with selling electric motor are always behind offering deals and offers to the customer. Through these events it is possible to provide a quality product with the most accessible value to please the final consumer. spherical roller bearings

Browse physical and virtual stores and access information about those products. It makes all the difference to compare values so that you have knowledge about which company is offering the best offer for you. It is well worth buying this machine because it is efficient and effective in its functions.

Know how to close the 6-prong three-phase electric motor

The electric motor that has six terminals or in the popular way known as electric 6-prong motor is an electric AC motor because it is a most popular electric machine in the industrial application as it is an excellent converter of electrical energy in mechanical energy.

The emergence of this electric motor took place in the hands of Nicola Tesla and the technological advance allows us to have today’s electric motor to be applied and industrial follow-ups.

Based on this principle, the three-phase induction electric motor on the winding closure types of the six-conductor three-phase electric motor with six-prong motor. It is necessary that the electric motor provides the option of six terminals to allow power through two different levels, for example 220V and 380v. Therefore, these two types of closure for this type of electric motor are: closing in triangle and closing in star.

In the vast majority, the electric motor has six cable ends in its junction box. The closing of this electric motor is done in a triangle and provides the closure at the lowest voltage that it is able to withstand.

8 advantages of a car with an electric motor compared to a car with a piston engine

An electric motor is an equipment that has an efficiency and for that reason, its efficiency can easily exceed the mark of 90%. Compared to the electric motor, the piston motor has much to be desired, as its efficiency does not exceed 35%.

The electric motor has a simpler constitution as it has much less moving parts and so the electric motor is a more reliable device and has lower maintenance cost.

The electric motor has as differential a high torque in its starting when it is in low revolutions and for that reason an electric car does not need to have the gear box or also called exchange and this makes the car is cheaper and reliable.

The electric motor features a regenerative braking system because it can also act as an electric generator and because of this, most of the kinetic energy of the car in the brakes is transformed into electrical energy that is stored in the batteries.

If compared to the piston engine, the electric motor has a faster start and when stopped in traffic the electric motor shuts off and when stepping on the accelerator the electric motor turns on almost instantaneously.

The electric motor is lighter, reaches a higher rotation than the combustion engine and vibrates and makes less noise.