GE 745 - Order Code

CHAPTER 2: OVERVIEW INTRODUCTION
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 2–3
FIGURE 2–1: Single line diagram
2.1.3 Order Codes
The order codes for the 745 Transformer Protection System are shown below.
Symbol Winding 2 protection elements Symbol Winding 3 protection elements
250/46 Negative sequence instantaneous overcurrent 350/46 Negative sequence instantaneous overcurrent
251/46 Negative sequence time overcurrent 351/46 Negative sequence time overcurrent
250P1 Phase instantaneous overcurrent 1 350P1 Phase instantaneous overcurrent 1
250P2 Phase instantaneous overcurrent 2 350P2 Phase instantaneous overcurrent 2
250N1 Neutral (3I
0
) instantaneous overcurrent 1 350N1 Neutral (3I
0
) instantaneous overcurrent 1
250N2 Neutral (3I
0
) instantaneous overcurrent 2 350N2 Neutral (3I
0
) instantaneous overcurrent 2
250G1 Ground instantaneous overcurrent 1 351P Phase time overcurrent
250G2 Ground instantaneous overcurrent 2 351N Neutral (3I
0
) time overcurrent
251P Phase time overcurrent 351G Ground time overcurrent
251N Neutral (3I
0
) time overcurrent 387TG Ground differential (restricted ground fault)
251G Ground time overcurrent 3THD Total harmonic distortion level
287TG Ground differential (restricted ground fault) 3AD Current demand
2THD Total harmonic distortion level
2AD Current demand