ABB PQFA, Instruction Manual

Page: 52 / 98

PQFA Instructions Manual
Asea Brown Boveri Jumet S.A.
52
9.3. Step 3
Step 3: Current transformer check
Improper CT connection is the most frequent cause of problems during
commissioning.
The following procedure will allow you to check the CT connection.
Warning: The secondary circuit of a loaded CT must never be opened
otherwise extremely high voltages may appear which can
lead to physical danger or destruction of the CT itself.
9.3.1. PQF connection diagram
Figure 9.1. shows the normal connection of the PQF. It must be noted that:
? ?
L1, L2 and L3 rotation must be clockwise,
? ?
The CTs must be on the supply (line) side of the PQF,
? ?
One secondary terminal of the CT must be earthed.
L1
L2
L3
Load side Supply side
K L
k l
K L
k l
K L
k l
PQF
X5.2
X5.3
X5.4
X5.5
X5.6
X5.1
L1 L2 L3
Figure 9.1. PQF connection