9
Functional safety
Integrated Safety Technology
Operating Instructions – MOVIDRIVE
®
modular
253
9.2.5 Restrictions
• Note that if the drive does not have a mechanical brake, or if the brake is defect-
ive, the drive may coast to a halt (depending on the friction and mass moment of
inertia of the system). In case of regenerative loads, or with axes that are loaded
with gravitational forces or driven externally, the drive can even accelerate. This
must be taken into account in a risk assessment of the system/machine. Additional
safety measures might have to be implemented (e.g. safety brake system).
The application inverter cannot be used without an additional brake system for ap-
plication-specific drive safety functions that require active deceleration (braking) of
the dangerous movement.
• When using the SS1(c) function as described in chapter "Drive safety func-
tions" (→ 2 251), the brake ramp of the drive is not monitored with respect to
safety. In case of a fault, the drive might not be decelerated after the delay time, or
it might be accelerated in the worst case. In this case, the STO function is only ac-
tivated after the set time delay has passed, see chapter "Drive safety func-
tions"(→2251). The resulting danger must be taken into account in the risk as-
sessment of the system/machine. Additional safety measures might have to be im-
plemented.
• The STO function cannot prevent a possible jerk or DC braking.
WARNING
The safety concept is only suitable for performing mechanical work on driven sys-
tem/machine components.
Result
When the STO signal is disconnected, the line voltage is still present at the DC link
of the application inverter.
• Before working on the electric part of the drive system, disconnect it from the
supply voltage using an appropriate external disconnecting device and secure it
against unintentional reconnection to the voltage supply.
WARNING
Electric shock due to charged capacitors.
Severe or fatal injuries.
• Observe a minimum switch-off time of 10 minutes after disconnecting the power
supply.
INFORMATION
In case of safety-related disconnection of the DC 24V supply voltage at X6 (STO ac-
tivated), the brake controller is switched off. The brake control in the application in-
verter is not safety-related.
24748536/EN – 11/2017
To Next Page
Loading...