To reverse a three phase motor, you simply swap two of the phase conductors.
Just as there are car engine and gearbox re-build workshops, there are specialist firms who have the necessary expertise and equipment to do motor rewinds. You could ask them if they can do an economical rewind on your motor or they may be willing to offer you a trade-in deal for it against a new or re-conditioned motor.
Most motors and Transformers have their windings potted in epoxy resin for mechanical reasons. Rewinding them - and re-testing them for satisfactory and safe operation - is a specialist job and is not a DIY project.
If you need to ask this question here, the best advice anyone should give you is to part-exchange the motor you can't use to someone who can supply you with a tested motor - with a warranty - that will do the job you want to use a motor for.
<><><>
Just as there are car engine and gearbox rebuild workshops, there are specialist firms who have the necessary expertise and equipment to do motor rewinds. You could ask them if they can do an economical rewind on your motor or they may be willing to offer you a trade-in deal for it against a new or re-conditioned motor.
1. Remove the Rotor
2. Study the old winding terminals.
3. Cut the old windings in order to count the incircuit one; also use micrometer screw guage to measure the diameter of the conductors that makes up the windings.
4. Remove the windings from their slots.
5. Scrape the slots in order to remove old insulation debris from them.
6. To rewind the motor back, insulate the slots with a paper insulating materials e.g Class F type that can withstand up to 155 deg. cent.
7. Do the coiling; you should consider its span etc
8. Insert the windings into the slots.
8. Join the windings e.g. to form series one; anyway it depends.
9. Cover the slot over the inserted coil with the same paper insulator.
10. Bind the winding with binding ropes.
11. Bring out the terminals to the terminating block on the motor.
12. Pour vanish on the windings to bind it and allow to dry.
13 Fix back the rotor.
14. You may also wish to change the bearings on the covers.
15. Terminate the terminals on the terminal block.
16. Test the motor either by connecting it in star or delta to the normal rated voltage.
17. Position the clamp meters to measure the current flowing in the suppling wire to ensure it is normal.
This is a job best left to the motor shop. They have the equipment to do the rewind. The motor is firstroasted in an oven up to 500 degrees F to soften the copper coils so that they can be cut out easily. The motor shop has pre made coil forms to wind the new motor coils on. When the new coils are in place the motor is dipped and baked again to harden the insulation material. Finally the motor is bench tested to make sure all three phases have the same current draw and it is within the original specifications of the motor. Usually good motor shops will then paint the outside of the motor to give it a new look.
switch two leads of the wires going to the motor for ex. L1,L2,L3 change to L1,L3,L2
To reverse a three phase motor, you simply swap two of the phase conductors.
how rewainding conection for 50 hp 3fase 750 rpm a/c motor
you can switch L1 and L2 and that will work >L1,L2,L3
You cannot run a three phase motor on single phase power. You'll burn the motor up within minutes. By the way, I've never seen or heard of a 380 volt motor. Do you mean a 480 volt motor? If so, the only way you can power it is with the correct full voltage and a 3 phase power supply.
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.
is it necessary to have three phase rotor
Then it is not a three phase motor.
If the motor is operated from a three phase three wire distribution system the motor will not need a neutral wire.
You cannot run a three phase motor on single phase power. You'll burn the motor up within minutes. By the way, I've never seen or heard of a 380 volt motor. Do you mean a 480 volt motor? If so, the only way you can power it is with the correct full voltage and a 3 phase power supply.
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.
It must be a three phase supply service to run a three phase motor.
You don't. A three phase motor will not start unless it is connected to a three phase supply.
Remove the motor from the system. Get the motor rewound at a motor rewinding shop. Replace the motor back into the system. While the motor is at the rewind shop find out why the motor burnt out. The first thing that should be checked is the overload protection. Make sure that is is the same as the motors full load amps.
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.
is it necessary to have three phase rotor
You never need a starter for a three-phase motor.
With no three phase power supply you can't use a three phase motor of any kind at all!
This question doesn't really make any sense - any of the two phase? A three phase induction motor requires 3 phases to start - if a single phase is lost while the motor is already running then yes the motor will continue to run. A three phase motor will not start if it is missing a phase.
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.
I have never come across a three phase capacitor start motor. Any three phase motors I have worked on are induction start.