text: <s>[INST] Auxilary Contacts on Service Disconnect If I have a roof mounted motor controlled by PF400 and I put a service discon. on the roof to be in code. Do I need to put aux cont. in my discon to protect the drive if someone shuts off the power while it is running, at 3grand apiece I DO NOT Want it burn it up. [/INST] DDP, as per my experience, opening the ouput line of a drive when the motor is running, can potentially damage the drive... I've seen it happen many times...:smileysad: Normally this protection devices should be used when drive is already stopped, to be a safety precaution before a maintanance guy want to work on the motor or the mechanical part beside it, to avoid an uncontrolled restart of the motor. It should not be intended as a way to stop the motor.So you have to be sure to stop the drive before open it, to avoid a potential burn... - fuzzy logic \\n </s>