Compax3 device description Positioning via digital I/Os70 192-120101 N11 C3I11T11 November 20073.9.3. Safety instructions for the ”safe standstill” function Safety functions must be tested 100%. Only qualified staff members are permitted to install the “Safe Standstill” featureand place it in service. For all applications in which the first channel of the “Safe Standstill” isimplemented by means of a PLC, care must be taken that the part of the programthat is responsible for current flowing to or not flowing to the drive is programmedwith the greatest possible care. The “Safe Standstill” application exampleof Compax3 with fieldbus should be considered.The designer and operator responsible for the system and machine mustrefer programmers who are involved to these safety-related points. Terminal X4/2 (GND 24 V and at the same time the reference point for the safetyrelay bobbin) must be connected with the PE protective lead. This is the only wayto ensure protection against incorrect operation through earth faults (EN60204-1Section 9.4.3)! All conditions necessary for CE conform operation (see page 15) must beobserved. It should be noted in connection with the “Safe Standstill” application exampleillustrated here that after the Emergency Power-off switch has been activated, nogalvanic isolation in accordance with EN 60204-1 Section 5.5 is guaranteed. Thismeans that the entire system must be disconnected from the mains power supplywith an additional main switch or mains power contactor for repair jobs. Pleasenote in this regard that even after the power is disconnected, dangerous electricalvoltages may still be present in the Compax3 drive for about 5 minutes. When using an external Emergency power-off module with adjustable delay time,(as illustrated in the “Safe Standstill” application example), it must be ensuredthat the delay time cannot be adjusted by persons not authorized to do so (forexample by applying a lead seal).The adjustable delay time on the Emergency Power-off module must be set to avalue greater than the duration of the braking ramp controlled by the Compax3with maximum load and maximum speed.If the setting range for the specified Emergency power-off module is notsufficient, the Emergency power-off module must be replaced by anothercomparable module. All safety-related external leads (for example the control lead for the safety relayand feedback contact) must absolutely be laid so they are protected, for examplein a cable duct. Short circuits and crossed wires must be reliably excluded! If there are external forces operating on the drive axes, additional measures arerequired (for example additional brakes). Please note in particular the effects ofgravity on suspended loads! If the power fails, the possibility must be considered that for the application withstop category K1, such as is described in the application example, it will no longerbe possible to execute the braking ramp controlled to speed 0. It is important to note that if the drive is being activated (Energize) by the RS232(RS485) interface, it may not be possible to execute switch-off by a controlledbraking ramp. For example, this is true when the set-up window of the C3ServoManager is used. If set-up mode is turned on, the digital I/O interface andfieldbus interface are automatically disabled.
