causes of high current on sag mill motors

Dial Indicator Alignment Basics

Dial Indicator Alignment Basics Dial indicators are measuring devices designed expressly to measure relative position The primary parts of a dial indicator are the face or dial the case and the plunger The plunger is a spring loaded part that can be depressed into the case causing the dial to move clockwise Dial Indicator...

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Power Surges HowStuffWorks

Feb 11 2021 0183 32 A more common cause of power surges is the operation of high-power electrical devices such as elevators air conditioners and refrigeratorsThese high-powered pieces of equipment require a lot of energy to switch on and turn off components like compressors and motorsThis switching creates sudden brief demands for power which upset the steady voltage flow in the electrical system...

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Bearing Handbook for Electric Motors

11 Find the cause of bearing failurBearings are built to last so frequent failures may point to an installation or lubrication problem SKF bearing analysis experts can identify the cause of bearing failure and help you prevent it in the future 12 The contact between the...

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THE ENGINEERING AND PROCESS EFFECTS OF CHOOSING

lines the motor is at risk of tripping due to high current depending on the conditions Safe operating of a mill and motor means that the process lines should appear below the red and blue lines across the whole range of speeds that are of interest In this example 13...

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Surge Current Causes and Prevention Ametherm

Inrush Current Switching power supplies AC motors and lighting ballasts can develop extremely high peak inrush currents at turn on unless inrush current protection is used Without protection the only limits on the amount of inrush current drawn is the line impedance input rectifier drop and capacitor equivalent series resistance...

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Types of Faults in Electrical Power Systems and Their Effects

Various electrical equipment like generators motors transformers reactors switching devices etc causes short circuit faults due to malfunctioning aging insulation failure of cables and winding These failures result in high current to flow through the devices or equipment which further damages it...

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Voltage Dip

A typical cause of voltage sags is the direct line start of large induction motors that normally draw 5 to 7 times their rated current during startup Short circuits in other branches of the supply system are also a common origin of voltage sags Also loose or defective wiring can cause voltage sags due to increased system impedance...

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Locked charge protection algorithms robust to coordination

Abstract A locked charge drop incident in a ball or sag mill is a catastrophic failure that causes high repair costs and loss of production The locked charge event also produces high currents and torque demands which can cause the drive or transformer overcurrent relays trip the mill motor...

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Causes of Voltage Sag GoHz

Apr 12 2016 0183 32 Causes of Voltage Sag Tuesday April 12 2016 Voltage issues resulting from high peak demands or equipment failure contingencies is known as low voltage or sometimes referred as under voltage we always include voltage drop caused by motor starting as sag On the other hand dealing with all these voltage events transients...

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Motors Power Conversion

Synchronous motors GE offers a full range of horizontal and vertical synchronous motors ranging from direct-drive high torque density motors at speeds as low as 20 rpm to turbo-type motors for compressor applications We can rapidly adapt our standard product platforms to cater for many applications or any purposed starting methods including...

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What happens when a device draws more current than the

\ \begingroup\ As a little information for the layman Theoretical power supplies can output infinite current Practical power supplies have an internal resistor that is the sum of all the wiring and other components In the model of such a power supply the resistor is what causes voltage to drop as current...

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Vibration Sag Mill Motor NDE Bearing AMP Maintenance Forums

At our mine we have an issue with vibration at the Sag Motor NDE bearing The bearing is a journal white metal bearing The motor has been running for about 14 months now The vibration at the NDE bearing was around 2mm/sec In the last month it has climbed...

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8 Common Hard Chrome Plating Problems To Avoid During

Burnt deposits of chrome are usually found near the high current density areas of the cylinder rod When the current density is too high the chromium is deposited very quickly This effect is magnified in the areas receiving the most current - leading to an extreme build-up of chromium deposits usually on the edges or end of the cylinder rod...

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Mill grinding

SAG is an acronym for semi-autogenous grinding SAG mills are autogenous mills that also use grinding balls like a ball mill A SAG mill is usually a primary or first stage grinder SAG mills use a ball charge of 8 to 21 The largest SAG mill is 42 128m in diameter powered by a 28 MW 38 000 HP motor...

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The Seven Types of Power Problems

Causes of impulsive transients include lightning poor grounding the switching of inductive loads utility fault clearing and Electrostatic Discharge ESD The results can range from the loss or corruption of data to physical damage of equipment Of these causes lightning is probably the most damaging...

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5 Causes of Motor Failure and How to Prevent Them

Also when laying out the workspace try to position motors away from grinding machines which produce large amounts of contaminants 5 Vibration Vibration can lead to many issues with the motor and can eventually cause the motor to fail prematurely Vibration is often caused by the motor being positioned on an uneven or unstable surface...

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Gearless Mill Drives Beneficiation Siemens Global

Frozen charge detection and automatic loosening with gearless mill drives SAG Conf 2015 Mill drives the desire for increased power and the associated limits and conditions SAG Conf 2015 The engineering and process effects of choosing a motor design speed SAG Conf 2015...

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Overheating Electric Motors A Major Cause of Failure

Apr 01 2003 0183 32 A mild overload was identified by examining the stator current of this motor However after looking at the true load to the motor an overload of nearly 20 percent was discovered This explains why these motors were failing The repair for each of these three motors ran into the hundreds of thousands of dollars...

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TECHNICAL NOTES 8 GRINDING R P King

8-3 Centrifugal force outward Fc mp 2 Dm 2 81 is the angular velocity mp is the mass of any particle media or charge in the mill and Dm is the diameter of the mill inside the liners Gravitational force Fg mpg 82 The particle will remain against the wall if these two forces are in balance ie...

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motor current spike Mike Holt s Forum

May 09 2013 0183 32 All What would cause a spike in the running current of a 3 phase motor The motor in question is 5000 hp 4 kV and powers a fan It will be running along just fine pulling around 570 amps then suddenly spike to about 630 amps for a second or two then return to...

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Running an induction motor at reduced voltage/overloading

Sep 22 2011 0183 32 In an induction motor the rotor windings bars will be cut by the rotating stator field at a max frequency when the rotor is stalled This induces a maximum voltage into the rotor resulting in a high current field strength in the rotor This field then reacts with the stator field to give high torque...

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Starting Methods to limit Starting Current and Torque of

Oct 27 2020 0183 32 Now since at starting N = 0 E b is also zero and under this circumstance the voltage equation is modified to For all practical practices to obtain optimum operation of the motor the armature resistance is kept very small usually in the order of 05 Ω and the bare minimum supply voltage being 220 volts Even under these circumstance the starting current I a is as high as 220/05 amp = 440 amp...

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Resolving Voltage Problems with AC Induction Motors EC M

Imbalanced motor voltages may cause a current imbalance that increases the operating temperature and energy losses of the motor In fact these voltages can magnify the current imbalance in the stator windings of a motor as much as 20 tim Unusually high numbers of motor failures During a voltage sag condition it maintains a current...

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The Hot Issue of Motor Temperature Ratings EC M

You can get overloads from high or low voltages voltage imbalance blocked ventilation high inertia loads frequent starts and other factors For example If a motor with Class A design 55 176 C temperature rise has Class B insulation then you could expect it to have a normal insulation life - even when ambient temperature is 65 176 C...

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What s causing your high motor current

Feb 23 2018 0183 32 The most common causes of high no-load current after a motor is rewound are incorrect winding data and stator core damage Incorrect winding data that increases the magnetic flux levels as compared with design levels will result in increased no-load current Although the effect on full-load current is not nearly as significant the higher flux...

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Mill Lubrication System

Jan 13 2014 0183 32 Parts of Ball Mill to be lubricated Trunnion bearing Feed end Gearbox Trunnion bearing Dis end Pinion Fig2 Ball Mill diagram Motor 21 Gathered Data This were the alarm gathered during my stay in the Mill MILL ALARM DATE Diff High Pressure Trunnion Feed End April 20 2013 SAG Bearing Recirculation Oil Inlet Temp...

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