Examples On How To Connect, Configure And Set Ct Inputs For Most Commonly Used Ct Connections - ABB REQ650 Applications Manual

1MRK 505 383-UEN A
4.2.2.4
Breaker protection REQ650 2.2 IEC
Application manual
Examples on how to connect, configure and set CT inputs for most
commonly used CT connections
Figure 9 defines the marking of current transformer terminals commonly used
around the world:
In the SMAI function block, you have to set if the SMAI block is
measuring current or voltage. This is done with the parameter:
AnalogInputType: Current/Voltage. The ConnectionType: phase -
phase/phase-earth and GlobalBaseSel.
I
Sec
x
a)
IEC06000641 V1 EN-US
Figure 9: Commonly used markings of CT terminals
Where:
a) is symbol and terminal marking used in this document. Terminals marked with a square
indicates the primary and secondary winding terminals with the same (that is, positive)
polarity
b) and are equivalent symbols and terminal marking used by IEC (ANSI) standard for CTs. Note that
c) for these two cases the CT polarity marking is correct!
It shall be noted that depending on national standard and utility practices, the rated
secondary current of a CT has typically one of the following values:
• 1A
• 5A
However, in some cases, the following rated secondary currents are used as well:
• 2A
• 10A
The IED fully supports all of these rated secondary values.
P1
(H1)
S1 (X1)
S2 (X2)
x
P2
(H2)
b)
Section 4
Analog inputs
SEMOD55055-296 v7
P2
(H2)
S2 (X2)
S1 (X1)
P1
(H1)
c)
en06000641.vsd
39