0
Your question is a little like asking, 'How long is a piece of string?'! Do the two motors have the same power rating, or are they different?
The rate at which energy is used by any machine is defined by its power rating. If the power ratings of two different machines are the same, then both machines use energy at the same rate. So if a single-phase motor has the same power rating as a three-phase motor, then they will both use exactly the same amount of energy over a given period of time.
So, if a single-phase motor has a greater power rating than a three-phase motor, then the single-phase motor will the greater amount of energy in a given period. On the other hand, if a three-phase motor has a greater power rating than a single-phase motor, then the three-phase motor will the greater amount of energy in a given period.
Wiki User
∙ 11y ago
Wiki User
∙ 8y agoI expect you are talking about induction motors. The drive is called a VFD, variable frequency drive. As the motor speed is proportional to frequency, it can be controlled within reason by varying the frequency of the supply using a specialised inverter. As the frequency varies, the voltage to the motor is also controlled so that the current remains in the ratings. The maximum torque is more or less constant as it depends on current. The speed changes, so that means the output power varies with the speed, as power is proportional to speed and torque.
It is possible to find models that use a single phase motor with three phase supply, or a three phase motor with single phase supply using this method, as the power to drive the motor is regenerated. However it is best to use a three phase motor, and the supply may need to be three phase to provide enough power for larger motors. Note that at low speeds the fan cooling becomes an issue.
Wiki User
∙ 6y agoSingle phase motor draws a higher current than 3 phase motor for a given KW load.
Wiki User
∙ 9y agoIf the two motors are designed to work at the same power with the same efficiency and the same case size, they will reach the same temperature.
Wiki User
∙ 10y ago110 volt supplies are usually single-phase so it's most likely to be a single phase motor. You can also tell by the number of wires or terminals. Only two indicates a single phase motor.
Add your answer:
Earn +20 pts
What is the difference between a one phase and a three phase motor. And if a three phase motor is given a single phase supply will it run or not?
The difference between a single phase and a three phase motor is the amount of power conductors that feed the device. As to the other part of the question a three phase motor will not start or run on single phase. The phase angles on three phase are 120 degrees apart on a single phase system they are 180 degrees apart.
Can you replace a three phase motor 3 Hp RPM 1420 with a single phase motor for a planer?
Probably not. The single phase three horse power motor will be much larger in physical size than its three phase counterpart, and will probably not fit.
How do you wire 3 phase power to 1 phase power diagram?
In an emergency and for a short period of time you can single phase a three phase motor but the motor will be loud, have terrible power characteristics and depending upon the use will burn up rather quickly. You should never try to run this in other than a life threatening emergency situation, the motors are not designed for it. Normally you don't. <<>> A three phase motor will not start on single phase. If the motor was started on three phase and loses a phase, it will stay running at a lower percentage of efficiency. Now a days the motor protection will not let a three phase motor run in a single phasing condition. All three phase legs of the motor are monitored and in a single phase condition the other two legs of the motor draw a higher current. This higher current is sensed by the motor's overload heaters in the motor's contactor and take the motor off line by opening the motor contactor. Now to the question, any two legs of a three phase system in electrical terms is known as single phase. As long as the three phase voltage matches the voltage needed in the single phase power diagram it can be connected to operate single phase equipment.
What is the weight of a single phase motor vs a three phase motor having same power?
They will not be very different.
Why is it called single phasing?
On a three phase system you have incorporated into it a potential of three single phase systems. A-B, B-C, C-A. Any two legs of a three phase system can be used as a single phase load. On a three phase system, be it a motor or a service, if one of the legs drops out for what ever reason, the remaining two legs are known as single phase. This is how the terminology became single phasing. As a side note a motor will run in a single phase condition, it just will not start. In motor control, a single phase condition is prevented by the use of overload heaters on all three voltage legs.
What is the difference between a one phase and a three phase motor. And if a three phase motor is given a single phase supply will it run or not?
The difference between a single phase and a three phase motor is the amount of power conductors that feed the device. As to the other part of the question a three phase motor will not start or run on single phase. The phase angles on three phase are 120 degrees apart on a single phase system they are 180 degrees apart.
How do you use a one phase motor in place of a three phase motor?
To use a single/one phase motor instead of a three phase motor is possible if you have a three phase power supply as you will only need to tap one of the three phases together with neutral and an earthwire, however to use a three phase motor instead of a single phase will require the provision of three phase power supply.
How do you start a three phase motor to a single phase power supply?
You don't. A three phase motor will not start unless it is connected to a three phase supply.
Can you replace a three phase motor 3 Hp RPM 1420 with a single phase motor for a planer?
Probably not. The single phase three horse power motor will be much larger in physical size than its three phase counterpart, and will probably not fit.
How will you understand whether a motor is single phase or three phase?
by no of terminals.
Is 380 volts electric motor a single phase or 3 Phase?
It is probably a three phase 50 Hz motor.
How do you wire 3 phase power to 1 phase power diagram?
In an emergency and for a short period of time you can single phase a three phase motor but the motor will be loud, have terrible power characteristics and depending upon the use will burn up rather quickly. You should never try to run this in other than a life threatening emergency situation, the motors are not designed for it. Normally you don't. <<>> A three phase motor will not start on single phase. If the motor was started on three phase and loses a phase, it will stay running at a lower percentage of efficiency. Now a days the motor protection will not let a three phase motor run in a single phasing condition. All three phase legs of the motor are monitored and in a single phase condition the other two legs of the motor draw a higher current. This higher current is sensed by the motor's overload heaters in the motor's contactor and take the motor off line by opening the motor contactor. Now to the question, any two legs of a three phase system in electrical terms is known as single phase. As long as the three phase voltage matches the voltage needed in the single phase power diagram it can be connected to operate single phase equipment.
What is the weight of a single phase motor vs a three phase motor having same power?
They will not be very different.
You have one hp three phase motor where as available power supply is only single phase how can you run this motor?
You will need to install a phase converter or change the motor to single phase. You can find a licensed electrician at www.contraxtor.com
How many earth wires are required for single phase motor?
There is only one ground wire needed on any motor, single or three phase.
What is the ideal insulation resistance to earth for a single phase and three phase motor?
Infinity
Why is it called single phasing?
On a three phase system you have incorporated into it a potential of three single phase systems. A-B, B-C, C-A. Any two legs of a three phase system can be used as a single phase load. On a three phase system, be it a motor or a service, if one of the legs drops out for what ever reason, the remaining two legs are known as single phase. This is how the terminology became single phasing. As a side note a motor will run in a single phase condition, it just will not start. In motor control, a single phase condition is prevented by the use of overload heaters on all three voltage legs.
