GE P642 User Manual

7.2 SECOND HARMONIC BLOCKING LOGIC
IA fundamental
V00703
IH2 I> Unblock
Low current (hard-coded)
IA 2
nd
harm / IA fund
&
&
IH2 I> Set
POC1 IA2H Start
POC1 IB2H Start
1
& POC1 IH2 Any St
POC1 IC2H Start
&
IH2 I> Unblock
&
IH2 I> Set
&
IH2 I> Unblock
&
IH2 I> Set
&
Low current (hard-coded)
Low current (hard-coded)
IA 2
nd
harmonic
IA fundamental
IB 2
nd
harm / IB fund
IB 2
nd
harmonic
IC 2
nd
harmonic
IC 2
nd
harm / IC fund
IC 2
nd
harmonic
Note: This diagram does not show all stages . Other stages follow similar principles.
Figure 105: Phase overcurrent 2nd harmonic blocking Logic
7.3 EF SECOND HARMONIC BLOCKING LOGIC
IN fundamental
V00704
IH2 IN> Unblock
Low current (hard-coded)
IA 2
nd
harm / IA fund
&
IH2 IN> set
EF1 IH2 Start
&
IN 2
nd
harmonic
Note: This diagram does not show all stages . Other stages follow similar principles.
Figure 106: Earth fault 2nd harmonic blocking Logic
7.4 APPLICATION NOTES
7.4.1 SETTING GUIDELINES
During the energization period, the second harmonic component of the inrush current may be as high as 70%. The
second harmonic lev
el may be different for each phase, which is why phase segregated blocking is available.
P64x Chapter 9 - Current Protection Functions
P64x-TM-EN-1.3 223

GE P642 Specifications

General

Brand	GE
Model	P642
Category	Relays
Language	English