- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
A 6 lead 400/230V IEC motor must be connected in Wye for the higher voltage, and as others have said, running a 400V (nominal) motor at 480V is perfectly fine. But that's not the only way they are made, the motor MIGHT HAVE been designed as a 690/400V motor. Weg used to do that on their crusher motors, it's a tough lesson to learn... The only other place I have seen 690V motors used like this? The marine industry... Hmmm... (looking at the OPs profile)
If it IS a 400/230V motor and they connected it to 480V in Delta, it would be as if the motor was designed for 277V and being fed 480V. It WILL RUN, and at the same speed, but will SATURATE and run hot, with higher (and possibly damaging) starting torque, then suffer premature death...
This graphic only goes to +15%, but you can imagine the extrapolated curves for +73%!
But on the other hand if it IS connected in Delta and is running normally, that means it was a 690/400V 50Hz IEC motor, capable of being run at 480V 60Hz by using the LOW VOTLAGE connection. I've never seen that on a motor this small, but it's not impossible.
If it IS a 400/230V motor and they connected it to 480V in Delta, it would be as if the motor was designed for 277V and being fed 480V. It WILL RUN, and at the same speed, but will SATURATE and run hot, with higher (and possibly damaging) starting torque, then suffer premature death...
This graphic only goes to +15%, but you can imagine the extrapolated curves for +73%!
But on the other hand if it IS connected in Delta and is running normally, that means it was a 690/400V 50Hz IEC motor, capable of being run at 480V 60Hz by using the LOW VOTLAGE connection. I've never seen that on a motor this small, but it's not impossible.