The controlling resistance is in the form of a rheostat, connected in star fig. So far we have been leaving them to run and only looking at them when they give trouble. Nei oil immersed slip ring motor starter ranges up to 500 h. Slip ring motor 5 frame size rated power duty cycle rated speed stator current rotor voltage rotor current pn kw % ed nn min1 i1 a u2 v i2 a 3en315sg 04 90 100 1478 171 310 177. What are the type of starter used for slip ring induction motor. Slip ring motors contents product description 62 overview of technical data 64 motor selection data series srspr variablespeed slip ring motors, continuous duty s1 65 series shsph version for crane applicationsiron and steel works, duty types s3, s4s5 67 bearings 626 terminal boxes 631 dimensions 634 6. Looking for square d magnetic motor starter, 120vac coil volts, nema size. Using the values of the starting resistors used, actual starting torque can be calculated. A woundrotor motor, also known as slip ringrotor motor, is a type of induction motor where the.
Oct 06, 2017 starting a 6kv 3ph 2,200 kw 1,000 rpm slip ring motor for a cement ball mill duration. Epm electrolytic starter can be used to start slipring motors from 500 kw to 20,000 kw. Woundrotor motors can be started with low inrush current, by inserting high resistance. Reload previously saved parameter settings from an internal file. Per phase equivalent circuit of induction motor to determine expressions for torque and power, the equivalent circuit in fig. If multiple step starting is required for extremely high erertia loads or for continuous opertion at multiple speeds multiple steps of rotor resistance can be used to accomplish this. Manufacturer of slip ring motor starter slip ring motor starter combined, ocb oil immersed slip ring motor starter offered by kaveri electrical industries, bengaluru, karnataka.
A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals. Know how to control the speed of slip ring motors bright. Learn more about the construction and operation of a slip ring induction motor. Pdf rotor side control of high power slip ring induction motor. All about motors 88 motor protection selection aids the eaton selector slide enables you to determine quickly and reliably which motor starter is the most suitable for the application concerned. A slipring motor is expensive, as are its controls, compared to a squirrel cage motor. To overcome substantially higher than a motor allows the rotor the limitations additional simple induction motor resistance to be controlled. This type of rotor has a 3phase, doublelayer, distributed winding consisting of coils used in alternators. It will supply the power necessary to drive the motor by resistance variation.
The stator of slip ring induction motor is very much the same as that of the squirrel cage induction motor, but the construction of its rotor is very much different. Slip ring motors with resistor starter have been a standard solution to achieve a kind of soft start, when either reduction of start motor current or torque is required, used for 50 years or so. Slip ring induction motors slip ring motor starter moflon. Jaw crusher slip ring motor starters crusher mills, cone. Rotor side control of high power slip ring induction motor using a single thyristor. Originally the motor had a resistance starter across the slip rings to slowly step to lower resistances but this was completely destroyed by fire caused by an external source there was no problem with the starter. Starting and control of threephase asynchronous motors eaton. Stator winding can be either star or delta connected depending upon the design. Each slip ring motor has a resistance value that when connected to the rotor will result in a starting torque of 100%. Already since 1927, we are a global manufacturer, supplier, and distributor of large slip ring motors up to 15000 kw and,8 kv. The slip ring motor has slightly different impedance response to a squirrel cage machine so the vfd control has to allow for this, but i believe most large vfd suppliers have this as standard.
The main difference in a slip ring induction motor is on the rotor construction and usage. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. A woundrotor motor, also known as slip ring rotor motor, is a type of induction motor where the rotor windings are connected through slip rings to external resistance.
Jun 06, 2015 starting of slipring motors these motors are practically always started with full line voltage applied across the stator terminals. We at naresh electricals industries are leading manufacturer of oil immersed slip ring motor starter. This does not involve the power from on rotor side be fed back to the source. Starting torque of slip ring motor and induction motor with. They are especially suitable for heavy load inertia applications. An engineer was originally looking into shorting out the slip rings and using a soft starter to drive the motor. Smooth starting of slip ring induction motors article pdf available in ieee transactions on energy conversion 124. Oct 22, 20 the solid state starter accelerates the motor to slip speed and then activates the contactor to short the rotor allowing the motor to accelerate to full speed. A contactor can make or break power to the circuit.
Liquid resistance starter for slip ring motor application applied to woundrotor asynchronous motor overload smoothly soft start are which three phase current 38ov20kv, power rating 30100. What links here related changes upload file special pages permanent link page information wikidata. Slip ring induction motor as an extension to the available non slip. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s. Slip ring motor starter slip ring motor starter combined. Oct 27, 2002 slip ring motor resistance posted in motor starting. Frequency inverter t1, controlled, stepless motor start with ratedload torque. Three phase slip ring induction motor my tech info. The speed of an induction motor is given as n 120fp 1s.
Some changes in the stator may be encountered when a slip ring motor is used in a cascaded system, as the supply for the slave motor is controlled by the supply from the rotor of the other slip ring motor with external resistance mounted on its rotor. Be specially designed for energy saving purpose which is totally enclosed and fancooled type. All process for starting is fully automated, that includes grease p. For satisfactory operation, motor a must be phase wound slip ring type with the stator to rotor winding ratio of 1. Can a slip ring motor run through a variable frequency drive. Hi sir i have seen your effective calculations for selection of slip ring motor resistance i have still some confusion in my mind as i have following relation to calculate the resistance rotor coefficient is k u lock rotor voltage i rated current of rotor at rated torque. Feb 25, 2017 depending on type of workload there are various type of starters for a slip ring induction motor.
The value of starting current is adjusted by introducing a variable resistance in the rotor circuit. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. For this only the operating voltage, the motor rating, the various shortcircuit ratings and coordination types are required. Starting of slip ring induction motor explained in an easy. It also requires meticulous and periodic maintenance of the brushes, brush gear, sliprings, external rotor resistances etc. The wound rotor induction motor or slip ring motor is widely used for applications requiring speed control or low starting currents. All nei oil immersed slip ring rotor starter is fitted with resistance, which is calculated as per rotor volt and rotor ampere and is installed into the starter only after checking its accuracy. Good performance, such as high safety, energy saving, compact design, low noise, little vibration, high torque big breakaway torque, reliable operation, stable running and convenient maintenance. The slip ring rotor chamber of the ic 411 slip ring induction motor is separated by what is known as a labyrinth seal, which prevents contamination from coal dust. A single phase induction motor is not selfstarting. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. A slip ring motor contains a slip ring, which is a mechanical device that transmits power and electrical signals from a stationary to a rotating structure. The main function of the contactor is to control the electric current to the motor. Stator rotor starter rotor starter auto transformer starter star delta starter oil circuit breaker overall dimensions wight without electrolyte hp kw type width a length b height c nett gross mm mm mm kg.
The value for k is different for each slip ring motor. Starting and control of threephase asynchronous motors. Slip ring motor conversion to vsd driven standard squirrel. Soft starter protection features apply to motor protection only. The stator circuit is rated as same in the squirrel cage motor, but the rotor is rated in frame voltage or short circuit current. Introduction in previous articles i have discussed the construction, operation, starting, speed control, and classes of. The rotor core is made up of steel laminations which have slots to accommodate formed 3single phase windings. Starting and control of slipring induction motors electrical.
Starting a 6kv 3ph 2,200 kw 1,000 rpm slipring motor for a cement ball mill duration. Dec 19, 2017 in this video you will learn connection of slip ring motor with starter panel now you can join our whatsapp group. Electrolytic starter lrs for high power slipring motors. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. Root 3 in ohm phaseand rotor resistance is then r s. The slip ring motor has very little application in industries. Maximum starting can be attained in the slip ring motor compared to squirrel cage motor by inserting an external resistance in each phase of the rotor circuit and cutting the resistance during starting speeds can be adjusted in the case of slip. If you have selected your slip ring motor to limit starting currents you can short out the slip rings and run your motor but the starting torque is reduced unless you use some features on the vfd to boost starting torque. The slip ring rotor chamber has two modification openings. Nei oil immersed rotor starter provides ample space for connection. During the startup a typical rotor has 3 poles connected to the slip ring. The stator is the same as is used with a standard squirrel cage motor. The slip rings need to be shortcircuited so the brushes can be removed allowing maintenancefree operation but this is never really a difficult procedure. A few of them have been playing up recently so im looking to service them all.
Where slipring motors are employed whose only purpose is limiting the starting current or a limited speed control, the resistance or electrolyte method of starting is. This is evident from the equivalent circuit shown in fig. In the case of phase wound induction motor the rotor of the motor is connected to delta connected resistor network through brush and ring,this external resistance helps us to control the starting torque of induction motor and hence speed can be c. A squirrel cage motor is thus preferred to a slipring motor.
Square d magnetic motor starter, 120vac coil volts, nema size. Advantages and disadvantages of slip ring induction motor. The liquid resistance starter nhp electrical engineering. Rotor side control of high power slip ring induction motor. This user manual 7101900e is compatible with mvs soft starters using version 1. A wide variety of slip ring motor starter options are available to you, such as starter assembly. The main motor is necessarily a slip ring induction motor but the auxiliary motor can be slip ring or squirrel cage induction motor. The motor speed is a function of its rotor resistance. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. General purpose slipring induction motors product catalogue. Starters limit the starting current in an induction motor which goes 56 times of full load current as slip remains 1. Speed control of wound rotor induction motor using rotor.
Electrical starters slip ring motor starter manufacturer. These starters help slip ring induction motor to get its speed to the pace slowly. A few quarries we look after have slip ring motor soft starters, vectrohm is the brand. The main methods employed for speed control of induction motors are as follows. A slipring motor also requires a larger space for the motor and its controls. All nei oil immersed slip ring motor starter conforms to iss specifications 8544. If connected to rotor winding the starting torque of motor is equal to the rated torque. The slip ring or wound rotor motor is an induction machine where the rotor comprises a set of coils that are terminated in sliprings to which external impedances can be connected. In addition, we have motors with airair heat exchangers ic 611, ic 616, and ic 666, pipecooled ic 511, open circuitcooled ic 01, as well as watercooled ic 81w threephase motors with slip ring rotor. Slip ring motor fundamentals bright hub engineering. Dec 19, 2016 the torque speed curves are completely different between an induction motor and slip ring motor. Carbon brush performance on slip rings mining electrical. Adjusting the resistance allows control of the speedtorque characteristic of the motor. Slipring motor starter,view slipring motor starter,zkec slipring motor starteron this product details page, hoister, crusher, compressor, fan and water pump under heavy load.
901 1441 130 1007 1017 1476 926 422 925 1579 888 774 643 245 1052 406 1304 1215 713 240 1542 126 641 729 1521 591 1122 1082 782 785 434 1221 900 773 1158 732 1271 38 1201 97 100