3ph motor

[mikebass87]

problem at work

a machine has a burnt out motor at a customers, engineer takes a new machine and when its delivered it needs the phases switched as it was running backwards, when the phases are switched and turned on it goes bang and burns out the motor.

another machine is delivered and the phases are correct from the start and all is well for time being

the supply is less than 400V, would the supply being so low be a cause for the motor to burn out?

 

[Knobhead]

What is the machine, it may help for us to know how to help.

 

[Marvo]

another machine is delivered and the phases are correct from the start and all is well for time being

Rotation direction of a 'machine' is usually determined by the connection of the supply, not by the internal wiring of the machine.

the supply is less than 400V, would the supply being so low be a cause for the motor to burn out?

As Tony said it would help to know what the machine actually is and if it's a DOL motor or star/delta. It would also help if you could give the on-load and off-load voltages of the supply.