GE P642 User Manual

V01503
Figure 171: Operating Characteristic Diagram
T
esting Differential Tripping Time Characteristics
When testing the differential tripping time characteristic, transient bias, CT saturation and No Gap settings may be
either disabled or enabled. An example is shown below:
V01504
Figure 172: Trip Time Test Plane
T
esting Harmonic Restraint
When testing 2nd or 5th harmonic restraint, transient bias may be either enabled or disabled, but the CT
Saturation and No Gap settings must be disabled. This is because harmonic blocking is used to unblock the
protection during normal energization of the transformer, while No Gap Detection and CT Saturation Detection is
used to unblock the protection during an internal fault. An example is shown below:
P64x Chapter 19 - Commissioning Instructions
P64x-TM-EN-1.3 429

GE P642 Specifications

General

Brand	GE
Model	P642
Category	Relays
Language	English