text: <s>[INST] Safety Contactor With PF525 Summary: Is there a need for oneJust planning a new project using a PF525 with a 22kw motor variable torque application, is there any need for a safety contactor when using this drive if so should it go line side or load side? i will be using the safe torque off function on the drive with a Compact Guard logix l43s Controller AENT with IB8S and OB8S safety IO. cost is not really an issue but would like the highest level of safety. Looking at 520-UM001I-EN shows one example with a contactor on the load side but i always thought this was a no no. Any input would be appreciated [/INST] You can put a contactor on the load side of the drive, but you should also run the drive-enable signal through it as well. I would not go this route. Putting a contactor on the line side is safest, but the drives have a once-a-minute power cycle limitation that more or less precludes putting a contactor there. Using a drive's safe-torque-off function means a contactor is not necessary. \\n </s>