10.
Monitoring functions
Definition
The monitoring functions signal a warning or a fault as soon as a certain value is
outside the permissible range. Faults generally cause an actuator shutdown.
10.1.
Torque monitoring
Torque monitoring has the following functions:
●
Valve overload protection against excessive torques (leads to switching off)
●
Torque warning before overload protection tripping (only in combination with
electronic control unit in the actuator)
Overload protection
Once the overload protection trips (torque exceeds set tripping torque), the actuator
is stopped.
Actuator controls generate a fault indication if:
●
Excessive torque occurs between end positions
●
Excessive torque occurs in the end positions and limit seating is set.
The fault indication is shown in the display
●
Status indication:
S0007 Fault
or
S0011 Failure
-
Details:
Torque fault CLOSE
or
Torque fault OPEN
The fault has to be acknowledged before the operation can be resumed:
1.
Either by an operation command in the opposite direction.
-
For
Torque fault CLOSE
: Operation command in direction OPEN
-
For
Torque fault OPEN
: Operation command in direction CLOSE
2.
Or, in case the torque applied is lower than the preset tripping torque after
tripping:
-
via the RESET push button in selector switch position Local control
(LOCAL).
-
or via command
Fieldbus RESET
(process representation output: byte 1,
bit 3).
Depending on the version, tripping torques for overload protection are either set via
switches in the actuator or via software parameters in the controls. For the settings,
refer to <Torque switching> chapter.
Torque warning
Requirements
Actuator with electronic control unit (MWG) .
The torque warning can be used e.g. for self-monitoring or for anticipating
maintenance requirements.
Customer settings M0041
Torque switching M0013
Wrn torque CLOSE M0769
Wrn torque OPEN M0768
Default value:
80 %
Setting range:
20 ... 100 %
of the set nominal torque
When exceeding the set limit values, the actuator is not stopped, however, the
controls generate a warning signal:
●
Status indications:
S0005 Warnings
or
S0008 Out of specification
-
Details:
Torque wrn CLOSE
or
Torque wrn OPEN
10.1.1.
Torque by-pass
By means of the torque by-pass, the torque monitoring is deactivated for a defined
(short) time. During this interval, the full actuator torque may be used, for example,
to release the actuator from a blocked end position or any other jammed position.
105
Actuator controls
ACV 01.2/ACVExC 01.2 Profibus DP
Monitoring functions
