# How many RPM is a 8 pole motor?

900 rpm

## How do you calculate the power rating of a motor?

Multiply the motor voltage by the full-load current. The result is in watts. Divide watts by 1,000 to give kilowatts. For example, 230 volts x 20 amps = 4,600 watts; 4,600 watts divided by 1000 = 4.6 kilowatts.

## What is the rating of a motor?

That’s why we are rated Motor in kW or HP (kilowatts/ Horsepower) instead of kVA. in more clear words, Motor only consume active power and provide mechanical power in HP or kW at motor shaft. In addition, Motor is a device which converts Electrical power into Mechanical power.

## How many kW is a 3hp motor?

Horsepower (metric) to Kilowatt Conversion Table

Horsepower (metric) Kilowatt [kW]
0.1 horsepower (metric) 0.kW
1 horsepower (metric) 0.kW
2 horsepower (metric) 1.4709975 kW
3 horsepower (metric) 2.kW

## What is short time rating of motor?

A short time rating of an electric motor can be defined as the extrapolated overload rating of the motor which it can supply for the specified short time without getting overheated. Now a days the machines are being designed and manufactured for short duration having sufficient overload torque capability.

## What is short time rating?

The short-time current rating of a circuit breaker is the ability of the circuit breaker to withstand the effects of the rated short-time current level over defined time duration. It demonstrates the ability of the breaker to remain closed for a time interval under high fault current conditions.

## What is continuous rating of motor?

The rating of the motor selected for this duty is called its continuous rating or design rating. By Continuous Duty Motor rating one means that it is the maximum load that the motor can give continuously over a period of time, without exceeding the temperature rise.

## Which motor is used in tramways?

This paper compares five different motor types used in variable speed drives: a dc motor with a mechanical commutator and with electromagnetic or permanent magnets excitation, a cage induction motor, asynchronous cascade with a slip‐ring motor and a brushless motor with PM excitation.

## Which braking is not possible in series motor?

regenerative braking

## Which locomotive has the highest operational availability?

Answer. Answer: Electric Locomotive:- An electric locomotive requires much less time for maintenance and repairs than a steam locomotive and such vehicles can, if desired, be kept in service for 95% or more. Diesel Locomotive:- It is available for hauling for about 90% of its working days.

## Which type of drive can be used for textile industry?

Textile Industry:- The process requires standard starting torque and standard overload capacity, at a constant speed. No speed control is required. The operation is at a constant speed. The standard squirrel cage induction motor the proper choice.

## What is group drive and individual drive?

when one prime mover or motor is used for the number of machine tools on common shaft then the drive is called as group drive . it is also sometimes called as line shaft drive. Cost of group drive is less for given capacity of load. Speed control of individual machine is very difficult.

## What type of electric drive is used in cranes?

Two of the cranes are rated at 16t and have been retrofitted with AC variable speed drives, while the two larger 25t cranes are using DC drives.

## In which drive each machine is driven by its own separate motor?

5. Which is the drive in which each machine has separate motors to drive? Explanation: Individual drive is the drive in which each machine has separate motors to drive. In these types of drive, each setup has their separate motors and gear pulley mechanism which together works to fulfil specific task.

## Why regenerative braking is not possible in series motor?

In case of DC Series motor, as the speed of Motor increases, the armature current and hence the field flux will decrease and therefore Back emf E can never be greater than the supply voltage V. Therefore, Regenerative Braking is not possible in DC Series Motor.

## Which drive is most suitable for multi motor drive?

From the wide range of possible drive units the most suitable is found to be the dc squirrelcage motor the speed of which is controlled by field weakening.

## Which starting method is the best method in induction motor?

The direct on line starter method, of an induction motor is simple and economical. In this method, the starter is connected directly to supply voltage. By this method small motors up to 5 kW rating is started to avoid the supply voltage fluctuation.

Plugging

## When one motor is used as a drive for two or more than machines such drive will be classified as?

Group electric drives are used in modern industries because of various complexities. Multi motor drives are used in heavy industries or where multiple motoring units are required such as railway transport. If we divide from another point of view, these drives are of two types: Reversible types drives.

## What is the advantage of motor generator set?

Low maintenance cost: The equipment can be maintained by electricians and/or mechanics; no specialist is required. Also, on horizontal, single-shaft MG sets, there is no coupling, gear nor belt to wear out. Exciters are brushless; there are no commutators or brushes to replace.

## Which drive has overload capacity?

High Overload capacity:- If the machines are liable to short but sharp overloads, group drive is again advantageous, because 100 percent overload on an individual machine will cause hardly 10 percent overload when driven by group drive.

## Why drives are used in motor?

A drive is the electronic device that harnesses and controls the electrical energy sent to the motor. The drive feeds electricity into the motor in varying amounts and at varying frequencies, thereby indirectly controlling the motor’s speed and torque.

three types

## What are 3 types of motor controls?

There are four basic motor controller and drive types: AC, DC, servo, and stepper, each having an input power type modified to the desired output function to match with an application.

## What is the principle of VFD?

Pulse Width Modulated Variable Frequency Drives. When operated from a constant frequency power source (typically 60Hz), AC induction motors are fixed speed devices. A variable frequency drive controls the speed of an AC motor by varying the frequency supplied to the motor.

## Where is VFD used?

The most common uses of a VFD are for control of fans, pumps and compressors, and these applications account for 75% of all drives operating globally. Soft starters and across-the-line contactors are other, less sophisticated types of motor controllers.