For existing synchronous motors to be applied to VFD operation, the synchronous motor must have its DC fi eld available at zero speed to develop starting and accelerating torque. • Two types of synchronous motor fi eld exciter designs that are suitable for starting and operating on a VFD use either DC slip rings, or an AC
Get Pricerotor slip rings Total 5 Terminals 3 for stator 2 for rotor slip rings 4 Terminals – 2 for armature 2 for field. Sometimes 2 additional for shunt field Terminals cabinet type and position DC field supply required. A modified Universal motor has brushes commutators (for use as power tool drives like drills,
Get PriceNov 21, 2012· With the advent of variable frequency drives (VFD), converting wound rotor hoist and crane controls to variable frequency control systems is becoming a relatively commonplace occurrence. Generally, the motor conversion involves grounding out the wound rotor slip rings internally, allowing removal of the rotor brush and slip ring assemblies.
Get PriceSlip ring motor conversion to VSD driven standard squirrel cage ac motor By J van Niekerk, Zest WEG Group Over a number of years slip ring motors have largely been replaced by standard squirrel cage ac induction motors, often in conjunction with ac Variable Speed Drives (VSDs).
Get PriceOct 25, 2016· The main difference between slip ring and cage types is that the slip ring rotor generally has a much lower slip at full speed than the cage rotor if it is properly shorted directly at the rings. We need to check that the variable frequency drive (VFD) slip setting can go low enough.
Get Pricebars and rings as a whole, they are much like an animal's rotating exercise cage, hence the name. In a WRIM (Slip Ring Motors), the rotor winding is made of many turns of insulated wire and is connected to slip rings on the motor shaft. An external resistor or other …
Get PriceApr 22, 2012· A VFD can be used with effectively any AC motor. Slipring 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. You have most likely difficulties to get a slipring motor replaced when it can't be no longer reworked.
Get PriceTypical slip rings in a motor. When a variable frequency drive (VFD) is added to an existing system, many potential problems may arise. This article details some of the factors to consider when installing a mediumvoltage (MV) VFD on an existing MV motor in order to ensure safe and efficient operations.
Get PriceFor high torque requirement, we need to over size both sq cage motor and variable frequency drive. Should we invest this solution? or operate the same system? sq cage Which reason sq cage motor and VFD system better than slip ring system? Some slipring motors can generate a very high starting torque, much higher than torque available at the output of squirrelcage motors inverter driven.
Get PriceNov 13, 2007· I have ran equipment with VFD drives supplying 460v 3PH motors through slip rings for years. If you set up a new project, make sure that the slip rings are rated for AC voltage and higher voltage as the case may be. Many DC motors are either 90V or 180V armatures and the original slip rings may be rated for this.
Get PriceOne of the main classifications of Asynchronous motors are the slip ring induction you know what happens to slip ring motor when external resistance is added? Also Know about the special constructional features of the rotor. Also appreciate the external resistances and carbon brush arrangements with the slip rings and advantages of slip ring induction motor.
Get Price"With a slip ring motor, it is necessary to short circuit the winding of the rotor. You can short circuit the winding of the rotor with a cable (cable of the last resistor in case of retrofit) to have more standard characteristics because this kind of motor has a low slip frequency.
Get PriceYour VFD can achieve the purposes of a slip ring and resistance starting, so I would shot out the wound rotor at the slip rings and run the motor as a normal induction motor, that way I eliminate unnecessary points of potential breakdown. We all know the problems associated with resistance starting, a VFD will eliminate all that.
Get PriceSlip ring motor starters DirectOnLine (DOL) starter: This is the simplest method to start the small induction motor up to 510 kilowatt .In this method rated supply voltage is directly applied to the starting current would be very large, up to 5 to 7 times of rated current.
Get PriceConverting a synchronous motor to an induction motor is easily done, to most motors, by shorting the rings, however, you would most likely need to use a properly sized VFD to get the starting torque you need. If you are interested to do such an upgrade you should consider the age of the motor and any other peripherals (gearbox, etc.) in the drive train.
Get PriceOct 25, 2019· General Electric, Frame 17, slip ring, rebuilt, 440 V. Clayton Electric Motor Repair, Elon College, NC 3365843756 (Email: jay ) Jay Clayton 200 HP
Get PriceDec 22, 2015· If converting a slip ring motor to VFD, you would first need to short the rotor bars, and this would best be done so that the brushes are made redundant, otherwise they will still need to be maintained. ... Sizing VFD for Slip Ring Motor 12/22/2015 2:51 PM.
Get PriceMay 13, 2017· With the advent of variablefrequency solidstate power supplies, speed variation can be provided by the more reliable, less expensive squirrelcage motor. Users occasionally inquire as to the feasibility of converting an existing woundrotor moto...
Get PriceMotors connected to VFDs receive power that includes a changeable fundamental frequency, a carrier frequency, and very rapid voltage buildup. These factors can have negative impacts, especially when existing motors are are a number of potential problems that can become real when a variable frequency drive (VFD) is used to power an existing induction motor.
Get PriceAn induction motor (sq cage) driven by VVVF/ VFD system is ideal replacement for slipring induction motor. However, the torque requirement / duty cycle of the crusher motor at various stages is important and the VVVF /VFD drive should be able to control the torque / …
Get PriceFeb 20, 2012· Re: VFDs and SlipRing Induction Motors 08/13/2009 8:49 AM Normally for the EOT Cranes when slip ring motors are used with resistance the speed is controlled through master controller. motor starts with slow motion and picks up speed slowly to avoid jerks.
Get PriceMar 24, 2007· Slip rings are not alone enough to identify what you have. Slip rings in AC motors can mean either a Wound Rotor motor or a Synchronous motor. There is essentially no difference between a synchronous motor and a synchronous generator other than the direction of …
Get PriceVfd on slip ring "wound rotor" motors Variable ? ? Motor Control? Variable Speed Drives. Feb 07, 2008· vfd on slip ring "wound rotor" motors posted in Variable Speed Drives: I am involved in converting a ball mill , which requires a large amount of starting torque, from a slip ring motor …
Get PriceHow to determine fullload RPM of an induction motor at any arbitrary frequency? Ask Question Asked 1 year, 11 months ago. ... , I am using a "VFDB" variable frequency drive on my induction motor. (manual, website) ... How can I find the slip speed of a slip ring induction motor without knowing the rotor speed (rated RPM)
Get PriceSlip power recovery system for variable speed operation of slip ring induction motor ... Package solution for slip ring induction motor with variable speed control 5 ABB Slip ring induction motors features description 67 ... The slip ring motors are used mainly for industrial applicaitons in cement, mining and water pumping ...
Get PriceSlip Ring or Wound Rotor Motors. 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. The stator is the same as is used with a standard squirrel cage motor.
Get PriceFeb 23, 2018· A slip ring induction motor ( wound rotor induction motor) has the main benefit that it is easier to start than a squirrel cage motor. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta...
Get PriceFeb 07, 2008· vfd on slip ring "wound rotor" motors posted in Variable Speed Drives: I am involved in converting a ball mill , which requires a large amount of starting torque, from a slip ring motor driven application to a vfd driven appl. .
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