ABB FSO-21, User Manual

Page: 56 / 540

56 Safety functions
Acknowledgement can be performed if:
• A safety function request is not active.
• STO: Delay defined by parameter
STO.13 Restart delay after STO or STO.14
Time to zero speed with STO and modoff has passed.
Note : If an SSE or SS1 request is received while the STO function is active, the
STO function must be completed before the acknowledgement is allowed. For
more information see section
Safe torque off (STO) on page 67 .
• SSE, SS1: Safety function is completed.
• SLS, Variable SLS, SDI: The monitoring has started.
When automatic acknowledgement is used, the FSO module acknowledges the
safety function immediately after the safety function request has been removed and
the above requirements are met.
When manual or acknowledgement from a safety PLC is used, the FSO module waits
for an external acknowledgement signal (either from the FSO I/O or from a safety
PLC) before it can acknowledge the safety function(s). After the FSO module has
received the signal, it acknowledges all active safety functions that can be
acknowledged with the same acknowledgement.
When several safety functions are active at the same time, the priorities described in
section
Priorities between safety functions (page 193 ) apply.
Note : If the FSO module is rebooted after a safety function request has been
removed but before it has been acknowledged, the FSO reboot acknowledges the
safety function.

DC magnetization and drive start modes
The correct operation of safety functions that limit or monitor motor speed (eg, SLS,
SMS, SSM) requires that ID-run has been performed prior to operation.
Note: Motor speed estimation is disabled on drive side when certain start modes with
magnetization or DC current control modes are active. SLS cannot provide reliable
protection during motor start, when:
1. Motor start with magnetization is requested: parameter 21.01 ‘Start mode’ = ‘Fast’
(0) OR ‘Constant time’ (1) OR ‘Automatic’ (2), OR
2. DC current control is enabled by parameter 21.08 ‘DC current control’. This
parameter is associated with ‘DC hold’ and ‘Post magnetization’ features, OR
3. Motor pre-heating is enabled by parameter 21.14 ‘Pre-heating input source’, OR
4. Continuous magnetization is enabled by parameter 21.12 'Continuous
Magnetization command' = 'Magnetization active' (1), OR
5. Auto-phasing is enabled, OR
6. Fly-start is on.