2.1 INTRODUCTION
Table 2–1: ANSI DEVICE NUMBERS AND FUNCTIONS
DEVICE
FUNCTION
NUMBER
27P
Phase undervoltage
49
Thermal overload protection
50BF
Breaker failure
2
50G
Ground instantaneous overcurrent
50N
Neutral instantaneous overcurrent
50P
Phase instantaneous overcurrent
50/74
CT trouble
2-2
DEVICE
NUMBER
50/87
51G
51N
51P
59N
59X
87B
Figure 2–1: SINGLE LINE DIAGRAM
B30 Bus Differential System
2 PRODUCT DESCRIPTION
FUNCTION
Unrestrained bus differential
Ground time overcurrent
Neutral time overcurrent
Phase time overcurrent
Neutral overvoltage
Auxiliary overvoltage
Restrained bus differential
GE Multilin