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1) If current, at 'on load' condition, reach or cross its rated value, then the speed of the motor will be decreased.

2) If there is any voltage droop occurs in the incoming supply then the speed of the motor will be decreased.

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What happen in shunt motor speed if the resistance is increased?

Its performance becomes worse. The speed will drop more when a mechanical load is put on the shaft.


Would it be correct to say with a fixed field voltagethe speed of a shunt motor is proportional to its armature voltage?

With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.


Does the RPM of a motor vary if a load is added to the motor?

The speed of an electric motor is directly proportional to the frequency of supply. The rpm written on the name plate is the maximum operating speed for the motor design. Typically, for a squirrel cage induction motors, the speed is constant by design and this type of motor cannot operate for a long time at speeds below the rated value. It is true that loading affects motor speed to some extend but the electric motor will accelerate to the rated speed. If the loading is within the design parameters of the motor, the electric motor speed will not drop. What typically happens is that if the loading increases, the speed goes down, and the current increases. Because voltage is constant, this result in a high I2R loss in the windings and the motor circuit protection trips on thermal and electrical overload. The formula for electric motor speed is SRPM=(120f)/P. The above is for AC motors. If you are referring to a DC motor, what you have stated is correct. The motor will slow down as load is added. That is why you are not supposed to run many DC motors under no load conditions - they will overspeed.


How do you calculate voltage drop for starting motor current and how to get the starting pf?

How do you calculate voltage drop for starting motor current


What causes sudden voltage drop in houses incase of ac?

Often, this is due to a sudden increase in the load current due, for example, to the the starting current of a motor which has been switched on -this causes a temporary increase in the voltage drop along the line, which is often noticed when the lights in a property temporarily dim. Other causes could be due to external sources, such as a neighbour operating welding equipment.

Related Questions

Where is the speed sensor that causes the speedometer to drop to zero and causes the transmission to drop to a lower gear?

it is on the transmission..best way to get to it is to remove pass side front wheel, remove motor mount. on top of trans is a round piece with 3 bolts and a plug. the speed sensor is there


Why the speed regulation does not apply to series motor?

Series motors have poor speed regulation because a reduced load causes the speed to rise, which causes the current to drop, which causes the speed to rise more because there is less field. Series motors are usually used to drive massive loads such as trams, where their high starting torque is a big advantage, and the speed cannot go out of control.


How speed of a squirrel cage induction motor can be varied?

There are two ways of changing the speed of AC motors,by altering the frequency or the number of poles in the motor. An increase in frequency of the supply voltage to the motor will cause it's speed to increase while reducing the frequency will causes the motor speed to drop. This is the method exploited by Variable Speed/Frequency Drive. The second method of changing the number of motor's stator poles is the difficult. The manufacture must design the motor such that the number of the motor's pole in operation can be increased or reduced. Increasing the number of poles increases the stator flux density which decreases the speed. Decreasing the number of poles does the opposite. This method is typically found in two speed motors and it's rarely used compared to VSDs.


What happen in shunt motor speed if the resistance is increased?

Its performance becomes worse. The speed will drop more when a mechanical load is put on the shaft.


What causes the blower motor to run only on the high setting on a 2003 Nissan Xterra?

The blower motor speed resistor is probably burned out.


Would it be correct to say with a fixed field voltagethe speed of a shunt motor is proportional to its armature voltage?

With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.


What causes the AC switch to turn on only on the five setting on a 2002 Chevy Impala?

If you are referring to the blower motor speed control, and you only have one speed, then the blower motor resistor pack is defective and must be replaced.


Why 3 phase induction motor never atteined sinkronas speed?

Induction motors run at sub synchronous speeds because the slip (difference between synchronous and actual speed) causes, or controls the electric field strength in the motor. As more load is put on the motor, the motor's speed decreases, increasing slip, and increasing the electric field strength.


What causes heavy vibration at high speed?

Could be motor mounts, the tires out of alignment or out of balance, or the steering needs work.


What calculated speed of a four-pole split-phase motor is 1800 RPM. However if you measure the shaft speed you will find it to be 1725 RPM. What causes this loss of rotational speed?

The loss of rotational speed is due to slip in the motor. Slip is a natural characteristic of induction motors and is necessary for torque production. The difference between the synchronous speed (1800 RPM) and actual shaft speed (1725 RPM) represents the slip in the motor.


Which longboard is better the landyachtz drop speed or the landyachtz switch?

Drop Speed Landyachts


What causes the heater blower motor in a 2003 Trailblazer to not work in speeds 1-3 but works in speeds 4 and 5?

Probably the blower motor speed resistor is partially burned out.