APPLYING VARIABLE FREQUENCY DRIVES TO EXISTING …

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

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MAINTENANCE SCHEDULE CHECKLIST

rotor 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,

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Winding down not out HOIST magazine

Nov 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.

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Slip ring motor conversion to VSD driven standard squirrel ...

Slip 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standard squirrel cage ac motor By J van Niekerk, Zest WEG Group Over a number of years slip ring motors have largely been replaced by standard squirrel cage ac induction motors, often in conjunction with ac Variable Speed Drives (VSDs).

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Can a slip ring motor run through a variable frequency drive?

Oct 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.

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Difference between Slip Ring Motor with Conventional Drive ...

bars 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 …

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can we replace any slip ring motor with an induction motor

Apr 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.

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Applying VFDs to existing motors | Processing Magazine

Typical 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.

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Is VFD system better than slip ring system in sq cage motor?

For 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.

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Slip Ring/VFD AutomationDirect Customer Forum

Nov 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.

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Slip Ring Motor Fundamentals

One 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.

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Is it possible to use slip ring motor with Altivar 71 drive.

"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.

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Can a VFD drive a slip ring motor?

Your 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.

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Motor Starters :Types of starter, Working of starter and ...

Slip 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.

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Change synchronous motor to induction motor VSD

Converting 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.

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Used MOTORS, , SLIP RING, 60 CYCLE (Wound Rotor) For ...

Oct 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

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Sizing VFD for Slip Ring Motor CR4 Discussion Thread

Dec 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.

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How to convert a slip ring motor into squirrel cage motor ...

May 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...

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Mating New Variable Frequency Drives to Existing Motors ...

Motors 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.

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Could we change Slipring Motor to Induction Motor?

An 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 / …

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VFDs and SlipRing Induction Motors CR4 Discussion Thread

Feb 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.

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Generate AC with Slip Ring Motor?

Mar 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 …

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How To Use Vfd In Slip Ring Motor In Crushing Equipment ...

Vfd 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 …

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vfd How to determine fullload RPM of an induction motor ...

How 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)

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Slip power recovery system for variable speed operation of ...

Slip 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 ...

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Slip Ring Motors LM Photonics

Slip 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.

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What is the working principle of slip ring induction motor ...

Feb 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...

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vfd on slip ring "wound rotor" motors Variable Speed ...

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 driven application to a vfd driven appl. .

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