YASKAWA F7 Technical Manual

Also see for Varispeed f7: Connection manual Programming manual User guide Instruction manual User manual

Contents

Date: 10/15/07, Rev: 07-10 Page 2 of 12 TM.F7.03First, there is nothing inherently unsafe about an F7 without the Safe-Off option. However, the F7’s operation isfully programmable. It is commanded by programmable inputs. Multiple sources (keypad, terminals, serialcommunications, option cards, etc.) can issue a Run command. When turning off the motor is essential to safety-related functions in the system, the F7’s flexibility necessitates a reliable mechanism to ensure that the motor willstop and cannot be started regardless of how the drive is programmed, configured or controlled otherwise.The Safe-Off option, when used with other safety components, provides protection according to EN954-1Category 3 for safe stop and protection against restart. An F7 drive equipped with the Safe-Off option is just onecomponent in a safety control system. To assure that the Safe-Off function appropriately fulfills the safetyrequirements of the application, a thorough risk assessment shall be done according to ISO12100 for the wholesafety system at the final installation. All components in the system must be appropriately selected and applied toachieve the desired safeguarding.The Safe-Off function performs a safe stop according to the EN60204-1 Stop Category 0 referred to as“uncontrolled stop by power removal” or “coast to stop.” Safe-Off is certified to meet the requirements of theEN954-1, Safety Category 3. The Safe-Off function is implemented totally in hardware on the F7 control board.Safe-Off disables the motor, not the drive controller. Power to the control board and display is maintained so allparameters, monitors and fault data may be read and observed. Also, all communications (Modbus, Profibus,DeviceNet, EtherNet/IP, etc.) stay active.The Safe-Off function uses two independent hardware channels to redundantly block the driver signals to theoutput devices (IGBTs) so the motor is disabled and operation prevented. Redundancy ensures that a single faultin any of the parts involved in Safe-Off does not lead to a loss of the safety function.Safe-Off is all electronic. No mechanical moving parts (relays) are involved in the Safe-Off circuitry. Safe-Off issuitable in applications classified as “medium risk” where coasting to a stop is the appropriate response to a faultcondition.Safe-Off merely prevents the motor from moving. The Safe-Off option does not serve as a motor disconnectingmeans (NEC Article 430 Part IX) and does not provide electrical safety. It is only suitable for preventing motoroperation when people are working near parts of a machine affected by the drive system.The Safe-Off option should not be used as the normal means to start and stop the drive.1.0 Overview