GE 889 Instruction Manual page 472

CONTROL
4–342
Figure 4-142: Navigation and SLD component selection
PB "Block" (Hardcoded SLD Pushbutton)
Blocking of a breaker or switch can be used for simply inhibiting the close or open
operation while in Local Mode. The selected breaker or disconnect switch can be blocked.
If block was not applied to the selected component, pressing "Block" PB will block either
the Open or Close command depending on the existing state (see
Pushbutton "Block" logic diagram). For example, if the selected component is in opened
state, pressing the PB "Block" will block the closing command, and vice versa (see figures:
Local Control for breakers/Local Control for switches). When the block is active, the letter
"B" appears in the SLD next to the controlled component
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
Figure 4-143:SLD