Non-Directional Instantaneous And Definitive Time, Phase And Residual Overcurrent Protection; Non-Directional Inverse Time Delayed Phase And Residual Overcurrent Protection - ABB Relion REC670 Applications Manual

Section 22
Requirements
³
E E
al
EQUATION1380 V2 EN-US
where:
I
op
I
pr
I
sr
I
r
R
ct
R
L
S
R
22.1.6.2 Non-directional instantaneous and definitive time, phase and residual
overcurrent protection
The CTs must have a rated equivalent limiting secondary e.m.f. E
to the required rated equivalent limiting secondary e.m.f. E
³
E E
al
EQUATION1381 V2 EN-US
where:
I
op
I
pr
I
sr
I
r
R
ct
R
L
S
R
22.1.6.3 Non-directional inverse time delayed phase and residual overcurrent
protection
The requirement according to Equation
the high set instantaneous or definitive time stage is used. In this case Equation is the only
necessary requirement.
460
æ
I
= × × ×
sr
5 I R
ç
alreq op ct
I
è
pr
The primary operate value (A)
The rated primary CT current (A)
The rated secondary CT current (A)
The rated current of the protection IED (A)
The secondary resistance of the CT (W)
The resistance of the secondary cable and additional load (W). The loop resistance containing the
phase and neutral wires, must be used for faults in solidly earthed systems. The resistance of a single
secondary wire should be used for faults in high impedance earthed systems.
The burden of an IED current input channel (VA). S
channel for I =5 A
r
æ
I
= × × ×
sr
1,5 I R
ç
alreq op ct
I
è
pr
The primary operate value (A)
The rated primary CT current (A)
The rated secondary CT current (A)
The rated current of the protection IED (A)
The secondary resistance of the CT (W)
The resistance of the secondary cable and additional load (W). The loop resistance containing the
phase and neutral wires, must be used for faults in solidly earthed systems. The resistance of a single
secondary wire should be used for faults in high impedance earthed systems.
The burden of an IED current input channel (VA). S
channel for I =5 A
r
ö
S
+ +
R
R
÷
L
2
I
ø
r
=0.020 VA/channel for I
R
ö
S
+ +
R
R
÷
L
2
I
ø
r
=0.020 VA/channel for I
R
133 and Equation
1MRK 511 358-UEN A
=1 A and S
r R
that is larger than or equal
al
below:
alreq
=1 A and S
r R
134 does not need to be fulfilled if
Application manual
(Equation 131)
=0.150 VA/
M11622-3 v5
(Equation 132)
=0.150 VA/
M11339-3 v5