Ct Locations For The Case Of Feeding Transformer And Backup Generator - ABB PQFM Instruction Manual

6.10.6 CT locations for the case of feeding transformer and backup generator

Many installations are fitted with backup generators to ensure the proper operation of
the installation in case of a mains supply outage.
A typical configuration is given in
Figure 46: Single line diagram of an installation with a backup generator
The CT connection must be such that the active filter works whatever the type of supply:
generator or transformer-MV network.
For each phase, one CT is installed in the transformer branch and one in the generator
branch. Those two CTs must be identical (X / 5 A) and must be connected to a
summation CT rated 5+5 / 5 A.
The CT ratio to be programmed in the filter is: 2×X/5.
connection diagram per phase.
P1, K
P2, L
Figure 47: CT connections for the case of a feeding transformer with backup generator
66 Electrical design and installation ç Manual Power Quality Filter PQFM
Figure
LOAD
G
S1, k
S2, l
S1, k
P1, K
S2, l
P2, L
(to be done for each phase)
46.
G
PQF
Figure 47
P1
S1
P2
P1
S2
P2
gives the corresponding
k
L
PQF