3 Functions and System Overview
3.1 System Overview
130BC308.10
Field bus
Interface
MCB 150/151
Safety Option
O
pt
io
n
A
O
pt
io
n
B
Internal Bus 1
Internal Bus 2
μ C
Control Card
IGBT
STO
37
E
M
PLC
EM
ER ENCY
G
ST OP
Illustration 3.1 FC 302 with Safety Option and Fieldbus Option
The safty option performs safety functions in accordance
with EN IEC 61800-5-2. It monitors safe motion sequences
on frequency converters, which are safely brought to a
stop and shut down in the event of an error.
The safety option
•
activates safety functions
•
monitors safe motion sequences
•
signals the status of safety functions to the safety
control system via possible connected Profibus
fieldbus
•
activates the selected failure reaction Safe Torque
Off or Safe Stop 1, in the event of an error
There are 2 variants of the safety option, one with HTL
encoder interface (MCB 151) and one with TTL encoder
interface (MCB 150).
The safety option is constructed as a standard option for
the VLT
®
AutomationDrive FC 302 and is automatically
detected after mounting.
The safety option can be used to monitor the stopping,
starting or speed of a rotating or laterally moving device.
As speed monitor, the option is often used in combination
with hard guarding, access doors, and safety gates with
solenoid-lock or -unlock safety switches. When the speed
of the monitored device drops below the set switch point
(where its speed is no longer considered dangerous), the
safety option sets S37 output low. This allows the operator
to open the safety gate. In speed monitor applications, the
safety output S37 is high for operation (when the motor
speed of the monitored device is below the set switch
point). When the speed exceeds the set value, indicating a
too-high (dangerous) speed, the safety output is low.
The frequency converter
•
removes the power to the motor,
•
switches the motor to torque-free, if Safe Torque
Off is activated
The safety control system
•
activates the safety functions via inputs on the
safety option
•
evaluates signals from safety devices, such as
-
E-STOP push buttons
-
Non Contact Magnetic switch
-
Interlocking switch
-
Light curtain devices
•
processes the safety option status function
•
provides safe connection between safety option
and safety control system
•
provides fault detection at activation of safety
functions (shorts across contacts, short circuit) on
signal between the safety control system and
safety option
3.1.1 Behaviour of Holding Brake
CAUTION
RISK OF HAZARD!
If external forces act on the motor (vertical axis) and an
unwanted movement, for example caused by gravity,
could cause a hazard, add measures for fall protection
before operating the motor.
Triggering the Safe Torque Off safety function means that
the delay time for motors with holding brake is not
effective. The motor cannot generate holding torque to
bridge the time to application of the holding brake. Check
whether additional measures have to be taken; for
example, this may cause the load of vertical axes to lower.
Functions and System Overvi...
Operating Instructions
10
Danfoss A/S © Rev. 2014-02-11 All rights reserved.
MG34W302
3
3
Summary of Contents for VLT Safety Option MCB 150
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