Safety Functions Integral to the SINAMICS
G120 and SINAMICS G120D Drive Systems
The drives are characterized
by a large number of integrated safety functions. They satisfy the requirements
of
Category 3 according to EN 954 1
Safety Integrity Level (SIL) 2 according to EN 61508
The Safety Integrated functions have been certified
by independent institutes.
Safe Torque Off (STO)
Description of functions
 This
function is a mechanism that prevents the drive from restarting unexpectedly,
in accordance with EN 60204-1, Section 5.4. Safe Torque Off disables the drive
pulses and disconnects the power supply to the motor (corresponds to Stop Category
0 of EN 60204-1). The drive is reliably torque-free. This state is monitored
internally in the drive.
Application, customer benefits
STO has the immediate effect that the drive cannot supply any torque-generating
energy. STO can be used wherever the drive will reach a standstill autonomously
due to the load torque or friction in a sufficiently short time or when coasting
down of the drive will not have any relevance for safety.
Safe Stop 1 (SS1)
Description of functions
 The
Safe Stop 1 function can safely stop the drive in accordance with EN 60204-1,
Stop Category 1. When the SS1 function is selected, the drive brakes autonomously
along an adjustable, monitored ramp and automatically activates the Safe Torque
Off and Safe Brake Control functions (if used) when 2 Hz is reached. If the drive
does not brake along the parameterized ramp when the stop function is activated,
Safe Torque Off and Safe Brake Control (if used) are activated instantaneously.
Application, customer benefits
This integrated fast-brake function eliminates the need for complex external
monitoring equipment. Furthermore, it is often possible to eliminate mechanical
brakes which wear, or to lessen the load on them, so that maintenance costs and
the stresses on the machine can be reduced. Safe Stop 1 is employed for applications
which require monitored braking, e.g. on centrifuges, conveyor vehicles, etc.
Safely Limited Speed (SLS)
Description of functions
 The
Safely Limited Speed function monitors the drive and, depending on the mode selected,
either limits the motor speed to a safe value or monitors the system directly
for a parameterized maximum speed. If the drive does not follow the parameterized
ramp or exceeds the maximum speed when the function is activated, it is either
braked along the Safe Stop 1 ramp or Safe Torque Off and Safe Brake Control (if
used) are activated (depending on which mode is selected).
Application, customer benefits
When many machines are being set up, the operating personnel must work on the
moving machine. This either occurs in stages because the operator must exit the
danger area repeatedly when the machine is started up, or the operator works
on the moving machine and is therefore exposed to increased risk. The SLS function
can save a considerable amount of time here and still increase the safety of
operating personnel.
Safe Brake Control (SBC) – only SINAMICS G120
Description of functions
 Safe
Brake Control SBC is used to control holding brakes which are operative at zero
current, e.g. motor brakes. The brake control circuit is a fail-safe, two-channel
design. The Safe Brake Control is activated when the Safe Torque Off function
is selected and when safety monitors with safe pulse disable are tripped.
This function is available only for the SINAMICS G120 system.
It requires an additional Safe Brake Relay.
Safe Brake Control does not detect mechanical faults in
the brake itself, such as worn brake linings.
he Safe Brake Relay is only capable of controlling 24 V
motor brakes.
Application, customer benefits
SBC can also be activated in combination with STO and SS1. SBC provides the option
of safely controlling a motor brake on the motor when the torque-generating energy
has been disconnected. As the Safe Brake Control module does not contain any
mechanical components, there are no restrictions on switching frequency. |
Pre sales info