easily. Wound rotor motors also can develop high starting torque at standstill - while maintaining low inrush. Long motor life is ensured with the use of external resistor banks or liquid rheostats that dissipate heat build-up generated during motor start-up. What makes the wound rotor motor a unique induction machine is its rotor. Instead of a ...
We operate ball mills with dual-coupled 3500hp 4160v wound rotor induction motors. We have recently experienced frequent arcing of the slip rings which seems to start on the center ring. The arcing damages the ring badly which requires us …
the mill shell. Drive motors In the case of ring gear drives, either wound rotor induction motors or synchronous motors can be used. Induction motors Wound rotor induction motors are usually equipped with starters for a controlled ramp up of mill speed with modest inrush currents. Motor speeds usually require the appli-cation of a speed reducer.
A very basic overview, but the advantage of wound rotor slip ring motor is that, through a LRS u can vary the resistance of the rotor. The advantages are 1. able to manipulate the torque speed curve, allowing u start with a much higher torque. Wound motors are suitable for application with heavy starting duties such as ball/sag mills, crushers etc.
Wound Rotor Motors also can develop high starting torque at standstill while maintaining low inrush. What makes the Wound Rotor Motor a unique induction machine is its rotor. Instead of a series of rotor bars, a set of insulated rotor coils is used to accept external impedances.
Post Glover Wound Rotor Motor Resistors The following table is for selecting the NEMA Class for an application in relation to starting torque and duty cycle. NEMA Classification of Resistors Approximate Class Numbers Applying to Duty Cycles Percent of Full-Load Current on First Point Starting @ Rest 30 sec. on Out of each 15 min. 5 sec. on
• Wound rotor/gearbox/twin pinion • Rotor drive (hypersynchronous) – multiple pinion. The LCI – twin pinion system has found acceptance overseas but has not been installed to date in Australia. The Fimiston 10.97 m (36 ft) SAG mill uses twin wound rotor/gearbox/ pinion drives with variable speed achieved through CCV systems.
operating cost and reduce availability of ball and SAG mills. Options for variable speed are DC motors, energy recovery systems for wound rotor motors and frequency converter drives. Improvements in power electronics technology and controls have resulted in variable frequency converters that offer high efficiency, high
JR ball mill motor adopts rotor string resistance full-voltage start-up, which has the advantages of small starting current, large starting torque, high efficiency, low noise, low vibration, good ventilation performance, reliable operation and convenient installation and maintenance.
Motor types: squirrel cage and wound rotor. Enclosures: TEFC, TENV and ODP. Fluid-shaft motors The Reuland fluid-shaft motor is designed especially for applications like conveying systems, crane travel drives, hammer and ball mills, car pullers, processing equipment and jib cranes. We combine a cushion drive fluid coupling with a Reuland
The field windings are thicker diameter, with fewer turns than in a DC shunt motor, so the resistance of the windings is lower. This allows the series motor to draw a large amount of current and produce a high amount of torque. Series …
Ball mill and motor 3 3.1 Ball mill load characteristics 3.2 Motor torque defined ... motor a) Starting or locked rotor torque is defined as the minimum torque ... The field circuit of the rotor is made up of copper wound pole pieces mounted on a spider around the shaft (Figure 6).
BALL MILL DRIVE MOTOR CHOICES – Artec Machine Systems. ball mills, the starting torque restrictions of some of the newer mill drive … Drive 4 – A 5000 HP, 1200 rpm induction motor with a VFD controller as a soft-start to a … »More detailed
YRQ ball mill motor adopts rotor string resistance full-voltage start-up, which has the advantages of small starting current, large starting torque, high efficiency, low noise, low vibration, good ventilation performance, reliable operation and convenient installation and maintenance.
From your message, you are installing a wound rotor motor on a ball mill. The wound rotor motor is usually used on this application because of it's superior starting characteristics. The Wound Rotor motor is able to develop a very high starting torque from zero speed to full speed at a relatively low start current.
system, couple the motor to the mill. Another possibility is to use a motor that can develop sufficient torque such as the wound rotor induction motor with rotor resistor starter. There are some drawbacks to be considered while using such a fix speed direct on line alternative independently if a high – or low speed solution is selected.
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. . We have sent the motor to our motor "guy" to refurbish and interconnect the rotor windings.Is there any advice or similar applications out ...
Start studying Three phase motors. Learn vocabulary, terms, and more with flashcards, games, and other study tools. ... What extra ratings does a wound rotor motor have on its name plate? voltage and current rating for the secondary. ... starting ball mills load conveyors.
We offer a full line of specialty products for reversing motors, DC injection braking, wound rotor motors, two speed motors, synchronous motors and more. DC Injection Braking Benshaw DC Injection Braking is available with the standard reduced voltage soft starters, or as a stand alone braking unit.
The use of wound rotor motors also provides for a low inrush situation, if the power system study demands it, and makes mill speed variation possible. This variation comes generally at a sace in motor efficiency because the …
Mills above a certain size will have an inching motor to assist starting of main drive motor. A liquid resistance stater will work well when using wound rotor induction motor. Attached Thumbnails. vinayak sathe. 15, Rangavi Estate, Dabolim Airport. 403801, Goa, India. [email protected]