Red Wiggler
Senior Member
Is a VFD considered a controller? If so then wouldn't the code require a disconnect switch ahead of the VFD (line side)?
So if you installed a disconnect switch ahead of the VFD and someone inadvertantly opened the switch, wouldn't the motor back feed into the VFD?
Would this situation be avoided if the 3 pole breaker ahead of the VFD was lockable for maintenance purposes?
The VFD has a lockable disconnect incoorporated into the unit. This would allow for motor work, or replacement. But what about work on the VFD? Does it need an external disconnect switch?
So if you installed a disconnect switch ahead of the VFD and someone inadvertantly opened the switch, wouldn't the motor back feed into the VFD?
Would this situation be avoided if the 3 pole breaker ahead of the VFD was lockable for maintenance purposes?
The VFD has a lockable disconnect incoorporated into the unit. This would allow for motor work, or replacement. But what about work on the VFD? Does it need an external disconnect switch?