GE Power Management
745 Transformer Management Relay
7-1
7 SCHEME LOGIC
7.1 INTRODUCTION
7
7 SCHEME LOGIC 7.1 INTRODUCTION
7.1.1 DESCRIPTION
The 745 instruction manual provides complete descriptions of the operation of each feature in the relay in
Chapter 5: SETPOINTS in the form of written descriptions. This chapter provides block diagrams for each fea-
ture. These diagrams are sequential logic diagrams illustrating how each setpoint, input parameter, and inter-
nal logic is used in a feature to obtain an output.
7.1.2 SETPOINTS
•
shown as a block with heading 'SETPOINT'
•
the location of setpoints is indicated by the 'Path’ heading of the diagram
•
the exact wording of the displayed setpoint message identifies the setpoint
•
major functional setpoint selections are listed below the name and are incorporated in the logic
7.1.3 MEASUREMENT UNITS
•
shown as a block with inset labelled 'RUN'
•
the associated pickup or dropout setpoint is shown directly above
•
operation of the detector is controlled by logic entering the 'RUN' inset
•
relationship between setpoint and input parameter is indicated by simple mathematical symbols: '<' (less
than), '>' (greater than), etc.
7.1.4 TIME DELAYS
•
shown as a block with the following schematic symbol:
•
the delay before pickup is indicated by t
PKP
, and the delay after dropout is indicated by t
DO
.
•
if the delay before pickup is adjustable, the associated delay setpoint is shown directly above, and the
schematic symbol indicates that t
PKP
= DELAY.
7.1.5 LED INDICATORS
•
shown as the following schematic symbol:
⊗
•
the exact wording of the front panel label identifies the indicator
7.1.6 LOGIC
•
described using basic ‘AND’ gates and 'OR' gates
The remainder of this chapter illustrates the block diagrams for each feature.
t
PKP
=DELAY
t
DO
=0
Summary of Contents for 745 TRANSFORMER MANAGEMENT RELAY
Page 30: ...2 8 745 Transformer Management Relay GE Power Management 2 3 SECURITY 2 GETTING STARTED 2 ...
Page 210: ...7 36 745 Transformer Management Relay GE Power Management 7 2 BLOCK DIAGRAMS 7 SCHEME LOGIC 7 ...
Page 322: ...9 12 745 Transformer Management Relay GE Power Management 9 3 USING 745PC 9 745 PC SOFTWARE 9 ...
Page 396: ...A 4 745 Transformer Management Relay GE Power Management A 1 FIGURES AND TABLES APPENDIXA A ...
Page 400: ...C 2 745 Transformer Management Relay GE Power Management C 1 WARRANTY INFORMATION APPENDIXC C ...
Page 406: ...vi 745 Transformer Management Relay GE Power Management ...
Page 407: ...GE Power Management 745 Transformer Management Relay NOTES ...
