MV Motors
MV Motors
(OP)
Seeking some basis guideline for the selection of fuses for protection of large medium voltage motors. We are a manufacturer of medium voltage motor control, but have encountered some large motor that exceed our database. Seem fuse manufactures have been reluctant to supply this data in recent years.





RE: MV Motors
RE: MV Motors
General Electric supplies MV fuses in their combination starers for MV. Their application engineers have a check sheet to help apply these fuses based upon your starting conditions. I am certain that Siemens, ABB, and other suppliers of MV motor starters can help you. These fuses all have time current curves available. As electricuwe stated, these are not for the main protection
RE: MV Motors
RE: MV Motors
RE: MV Motors
If these motors are larger than your data base, and in the medium voltage group, the fuses are for short circuit protection of the conductors feeding the motors.
Protection of the motors will be by overload relays, and possibly by thermal modelling, differential protection and temperature monitoring.
If, despite the motor protection, the motor burns up, or if there is physical damage to the motor circuit conductors the fuses will interupt the fault current.
respectfully