3
Safety concept
Drive safety functions according to EN 61800-5-2
Manual – MOVISAFE
®
CS..A Safety Card (Version 2)
24
3.7.7
SS2(a) – Safe Stop 2 with control and monitoring of the deceleration ramp
When the SS2(a) function is active, the drive inverter brings the motor to a standstill e-
lectrically. The deceleration behavior is not controlled and monitored in a safety-re-
lated manner. The position must be safely monitored after standstill (SOS function ac-
cording to EN 61800-5-2). The STO drive safety function will be triggered if the decel-
eration value is exceeded while stopping or if movement occurs during standstill. STO
means that standstill has to be ensured by a mechanical brake.
This drive safety function corresponds to a controlled stop of the drive according to
EN 60204-1, stop category 2.
t
1
t
2
t
V
28259419659
= Drive safety function controls and monitors
= STO drive safety function active
v
= Speed
t
= Time
t
1
= Point in time when SS2(a) is activated and motor deceleration is triggered.
t
2
= Time when SOS is triggered.
28482271/EN – 03/2019
