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Overvoltage on DC motor armature can be detrimental to the life of the windings. Most modern drives have voltage feedback and detect this condition.
A likely cause is loss of speed feedback, voltage feedback or the load driving the motor beyond what the drive can handle.
Fixes for the above: -check and mend the feedback circuits and associated hardware (cable, tachos, input cards, processor cards)
-change from a single quadrant to a four quadrant drive
-install a braking resistor
-inspect the mechanical system to ensure there are no wild split points in the gearing
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What is separately excited DC motor?
The main difference between the Separately excited motor and the shunt motor is the field cct where as in the second it has its own voltage supply.AnswerI think you mean 'generator', not 'motor'. A 'self-excited' motor is one in which the output supplies the field current, as well as the load current. A 'separately-excited' motor is one in which the field current is provided from an external source.
What is reason for armature over voltage in 450 kw dc motors?
Here we used dcon digital dc drive
What is a rocker arm in a DC motor and what will happen if the rocker arm connections are changed?
A rocker arm holds a carbon brush. In other words it is a carbon brush holder. Changing over the rocker arm connections is the same as changing over the armature connections and will make a DC motor turn in the reverse direction assuming that the magnetic orientation of the motor's field stays the same.More detailDC motor having a field windingIf the stator's field is created by a field winding and that winding's connections are changed over at the same time as the armature's connections are changed over, then the DC motor's direction of rotation will be the same as before.If the stator's field is created by a field winding and that winding's connections are not changed over at the same time as the the armature's connections are changed over, then the DC motor will turn in the reverse direction.DC Motor having a field created by a permanent magnetIf the stator's magnetic field is created by a permanent magnet and the orientation of that magnet is reversed at the same time that the armature connections are changed over, then the DC motor's direction of rotation will be the same as before.If the stator's magnetic field is created by a permanent magnet and the orientation of that magnet is not reversed at the same time as the armature connections are changed over, then the DC motor will turn in the reverse direction.
What is power cable size for 1 kw 1 phase motor over 500 meters?
It depends on the voltage that the motor needs, because a higher voltage requires less current for a given amount of power. Also a higher voltage can tolerate a higher voltage drop. So there are two things that lead to a thinner wire when the voltage is higher.
What size wire should be use for connecting a 110 kw motor over a distance of 108 meters?
This is a voltage drop question. To answer this question a voltage must be given.
why starter motor armature over heat?
Usually caused by worn bearings.
What is separately excited DC motor?
The main difference between the Separately excited motor and the shunt motor is the field cct where as in the second it has its own voltage supply.AnswerI think you mean 'generator', not 'motor'. A 'self-excited' motor is one in which the output supplies the field current, as well as the load current. A 'separately-excited' motor is one in which the field current is provided from an external source.
What is reason for armature over voltage in 450 kw dc motors?
Here we used dcon digital dc drive
What is a rocker arm in a DC motor and what will happen if the rocker arm connections are changed?
A rocker arm holds a carbon brush. In other words it is a carbon brush holder. Changing over the rocker arm connections is the same as changing over the armature connections and will make a DC motor turn in the reverse direction assuming that the magnetic orientation of the motor's field stays the same.More detailDC motor having a field windingIf the stator's field is created by a field winding and that winding's connections are changed over at the same time as the armature's connections are changed over, then the DC motor's direction of rotation will be the same as before.If the stator's field is created by a field winding and that winding's connections are not changed over at the same time as the the armature's connections are changed over, then the DC motor will turn in the reverse direction.DC Motor having a field created by a permanent magnetIf the stator's magnetic field is created by a permanent magnet and the orientation of that magnet is reversed at the same time that the armature connections are changed over, then the DC motor's direction of rotation will be the same as before.If the stator's magnetic field is created by a permanent magnet and the orientation of that magnet is not reversed at the same time as the armature connections are changed over, then the DC motor will turn in the reverse direction.
How can the direction of rotation of a DC shunt motor be reversed?
DC shunt motor can be reversed by changing the polarity of either the armature coil or the field coil.
How to control motor rpm?
For AC motor, you can change motor RPM by changing its supply voltage or by changing supply frequency. For DC motor, you can change motor speed by controlling armatyre voltage or field current.
What is power cable size for 1 kw 1 phase motor over 500 meters?
It depends on the voltage that the motor needs, because a higher voltage requires less current for a given amount of power. Also a higher voltage can tolerate a higher voltage drop. So there are two things that lead to a thinner wire when the voltage is higher.
What size wire should be use for connecting a 110 kw motor over a distance of 108 meters?
This is a voltage drop question. To answer this question a voltage must be given.
What is the effect of overvoltage on small electric loads?
The effect of modest over voltage on any type of load is added heat and higher current flow . As the voltage increases past modest an arc will eventually happen.
What effect does advancing the spark into the motor cylinder have on starting?
It will usually turn over faster.
Causes of over temperature of induction motor?
the main reason is the amount of current flowing in the motor's winding is huge (over current) that why temperature begins to build up, continues using may end up to a burned motor. over voltage, defective bearing / bushing, shaft misalignment, defective insulation are some of the reason why motor experience over current.
What are v and inverted v curves?
V Curve- Excitation vs Armature currentV curve is the graph showing the relation of armature current as a function of field current in synchronous machines. The purpose of the curve is to show the variation in the magnitude of the armature current as the excitation voltage of the machine is varied.Inverted V Curve- Excitation vs Power FactorThe synchronous motor "V Curves" shown above illustrate the effect of excitation (field amps) on the armature (stator) amps and on system power factor. There are separate "V" Curves for No-Load and Full-Load and sometimes the motor manufacturer publishes curves for 25%, 50%, and 75% load. Note that the Armature Amperage and Power Factor "V" Curves are actually inverted "V's".Assume it is desired to determine the field excitation which will produce unity power factor operation at full motor load. Project across from the unity power factor (100%) operating point on the Y-Axis to the peak of the inverted Power Factor "V" Curve (blue line). From this intersection, project down (red line) from the full-load unity power factor (100%) operating point to determine the required field current on the X-Axis.In this example the required DC field current is shown to be just over 10 amps. Note at unity power factor operation the armature (stator) full-load amps is at the minimum value.Increasing the field amps above the value required for unity power factor operation will cause the machine to run with a leading power factor, while field weakening caused the motor power factor to become lagging. When the motor runs either leading or lagging, the armature (stator) amps increases above the unity power factor value.
