Woodward MRM4, Manual

Page: 237 / 460

Blockings
Blockings
The device provides a function for temporary and permanent blocking of the complete protection functionality or
of single protection stages.
Make absolutely sure that no illogical or even life-threatening blockings are
allocated.
Make sure that you do not carelessly deactivate protection functions which
have to be available according to the protection concept.
Permanent Blocking
Switching ON or OFF the complete protection functionality
In module »Protection«, the complete protection of the device can be switched on or off. Set the parameter
Function to »active« or »inactive« in module »Prot« .
Only if in module »Prot« the parameter Function is = »active« , the
protection is activated; i.e. with »Function« = »inactive«, no protection
function is operating. Then the device cannot protect any components.
Switching modules ON or OFF
Each of the modules can be switched on or off (permanently). This is achieved when the parameter » Function«
is set to »active« or »inactive« in the respective module.
Activating or deactivating the tripping command of a protection stage permanently
In each of the protection stages the tripping command to the CB can be permanently blocked. For this purpose
the parameter »TripCmd Blo« has to be set to »active« .
Temporary Blocking
To block the complete protection of the device temporarily by a signal
In module »Prot« the complete protection of the device can be blocked temporarily by a signal. On condition
that a module-external blocking is permitted »ExBlo Fc=active« . In addition to this, a related blocking signal
from the »assignment list« must have been assigned. For the time the allocated blocking signal is active, the
module is blocked.
If the module »Prot« is blocked, the complete protection function does not
work. As long as the blocking signal is active, the device cannot protect
any components.
To block a complete protection module temporarily by an active assignment
•
In order to establish a temporary blockage of a protection module, the parameter »ExBlo Fc« of the
module has to be set to »active« . This gives the permission: »This module can be blocked«.
•
Within the general protection parameters a signal has to be additionally chosen from the »
ASSIGNMENT
LIST
«. The blocking only becomes active when the assigned signal is active.
To block the tripping command of a protection stage temporarily by an active assignment.
The tripping command of any of the protection modules can be blocked from external. In this case, external
EN MRM4 01/11 Page 237