GE 845 Instruction Manual page 118

SOFTWARE INTERFACE
NOTE:
NOTE:
NOTE:
NOTE:
Breaker/Switch Position
Open
Closed
Open
Closed
Open or Closed
Open or Closed
Open or Closed
3–44
If upgrading from firmware 1.7x or earlier, the breaker operations from the front panel now
follow select-before-operate mechanism. The breaker must be first selected by browsing
and pressing Enter key for selection. Once selected, the breaker can be opened or closed
with the open and close pushbuttons.
Control Operations
The control operations carried out through the front panel of the relay are done only in
Local Mode ( Setpoints > Control > Local Control Mode > Local Mode
operations can be carried out by pressing the Open and Close pushbuttons on the relay
front panel. Other operations such as tagging, blocking and bypassing can be carried out
by pressing the control pushbuttons that appear after the control object selection.
Remote operations are allowed for opening, closing, blocking, and bypassing. Tagging
must be done locally.
It is recommended to use tagging for maintenance purposes only. When a breaker or a
switch is tagged, it cannot be bypassed although the letters "By" may appear below the
element on SLD.
If breaker is selected and relay status is changed to Out-of-Service, the breaker control
actions, such as tag, blocked, bypass and open/close are blocked. The breaker may remain
in the selected state, but no action can be executed.
Once the selected breaker or switch is tagged, a letter "T" appears below the associated
element. Similarly, for blocking, letter "B" appears and for bypassing, letters "By" appear
below the associated breaker or switch as shown in the last column of the following figure.
The blocking and bypassing letters also appear if the breakers/switches are blocked or
bypassed remotely. These are linked to their respective breaker/switch in the SLD
Configurator window so that when that breaker/switch is deleted, the letters also get
deleted.
Permitted breaker/switch operations are described in the following figure below when
various letter indications are present under the control element.
Figure 3-24: Letter Indications for breaker/switch operations
Letter Indication Operation
B Closing is blocked.
B Opening is blocked.
B By Closing is blocked but bypassing is allowed.
Closing is permitted.
B By Opening is blocked but bypassing is allowed.
Opening is permitted.
T Tagged by operator. No operation allowed.
T By Tagged by operator. No operation allowed.
T B By Tagged by operator. No operation allowed.
For detailed tagging, blocking and bypassing operations, refer to the section
Mode (breakers and switches).
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INTERFACES
). Opening and closing
Sample Indication
BKR1
T B By
Local Control