The Safe Stop W68 in Danfoss VLT frequency converters refers to a safety feature that initiates a Safe Torque Off (STO) function. This means the motor connected to the VLT drive is brought to a safe stop by cutting off power in a controlled manner.

Here's a breakdown of the Danfoss VLT Safe Stop (W68):

1. Function: When triggered, the Safe Stop ensures a safe stop for the motor by disconnecting power. This is crucial for preventing injuries or equipment damage in emergency situations.
2. Activation: Various safety mechanisms or conditions wired to the VLT drive can trigger the Safe Stop. These might include external emergency buttons, pressure switches, or temperature sensors exceeding safety limits.
3. Safety Note: It's important to remember that Safe Stop does not isolate the drive from the mains power. Its primary function is to stop the motor for safety reasons.

The Safe Stop can be triggered by various safety mechanisms or conditions wired to the VLT drive. These might include emergency stop buttons, safety gates, or external control systems.