A45638 What this chapter contains This chapter describes the Safe torque off (STO) function of the drive and gives instructions for its use. Description The Safe torque off function can be used, for example, to construct safety or supervision circuits that stop the drive in case of danger. Another possible application is a prevention of unexpected start-up switch that enables short-time maintenance operations like cleaning or work on non-electrical parts of the machinery without switching off the power supply to the drive. Note: The Safe torque off function does not disconnect the voltage from the drive, see the warning on page 128. When activated, the Safe torque off function disables the control voltage of the power semiconductors of the drive output stage (A, see diagram on page 124), thus preventing the drive from generating the torque required to rotate the motor. If the motor is running when Safe torque off is activated, it coasts to a stop. The Safe torque off function has a redundant architecture, that is, both channels must be used in the safety function implementation. The safety data given in this manual is calculated for redundant use, and does not apply if both channels are not used. 122 Safe torque off function The Safe torque off function of the drive complies with these standards: The function also corresponds to Prevention of unexpected start-up as specified by EN 1037:1995 + A1:2008 and Uncontrolled stop (stop category 0) as specified in EN 60204-1:2006 + AC:2010. Compliance with the European Machinery Directive See section Compliance with the European Machinery Directive on page 100. Standard Name EN 60204-1:2006 + AC:2010 Safety of machinery – Electrical equipment of machines – Part 1: General requirements IEC 61000-6-7:2014 Electromagnetic compatibility (EMC) – Part 6-7: Generic standards – Immunity requirements for equipment intended to perform functions in a safety-related system (functional safety) in industrial locations IEC 61326-3-1:2008 Electrical equipment for measurement, control and laboratory use – EMC requirements – Part 3-1: Immunity requirements for safetyrelated systems and for equipment intended to perform safetyrelated functions (functional safety) – General industrial applications IEC 61508-1:2010 Functional safety of electrical/electronic/programmable electronic safety-related systems – Part 1: General requirements IEC 61508-2:2010 Functional safety of electrical/electronic/programmable electronic safety-related systems – Part 2: Requirements for electrical/electronic/programmable electronic safety-related systems IEC 61511:2003 Functional safety – Safety instrumented systems for the process industry sector IEC/EN 61800-5-2:2007 Adjustable speed electrical power drive systems – Part 5-2: Safety requirements – Functional IEC/EN 62061:2005 + AC:2010 Safety of machinery – Functional safety of safety-related electrical, electronic and programmable electronic control systems EN ISO 13849-1:2008 + AC:2009 Safety of machinery – Safety-related parts of control systems – Part 1: General principles for design EN ISO 13849-2:2012 Safety of machinery – Safety-related parts of control systems – Part 2: Validation Safe torque off function 123 Connection principle Connection with internal +24 V DC power supply Connection with external +24 V DC power supply S+ + 24 V DC S1 S2 T1/U, T2/V, T3/W Control board SGND STO UDC+ |
