OMICRON
39
Power transformers
5
Power transformers
General
• The transformer must be taken out of service and completely isolated from the power system.
• The proper grounding of the transformer tank has to be checked.
• All bushing high-voltage terminals must be isolated from the connection lines.
• All bushing terminals of one winding group, which means A, B, C (and Neutral) of high-voltage
winding, A, B, C (and Neutral) of low-voltage winding and A, B, C (and Neutral) of tertiary winding
have to be connected by a copper wire (see Figure 5-1).
Figure 5-1: Three-winding transformer with connected windings
• The neutral terminals of all Y-connected windings with outside-connected Neutral have to be
disconnected from ground (tank).
• If the transformer has a tap changer then it should be set to the neutral position (0 or middle tap).
• Connect the
Control Device
+
CP TD1
ground terminal to the transformer's (substation) ground.
N (L)
C (L)
A (L)
B (L)
A (H)
B (H)
C (H)
N (H)
HV
LV
TV
B (T)
C (T)
A (T)
A
B
C
Summary of Contents for CP TD1
Page 1: ...CP TD1 User Manual...
Page 70: ...ENU 1035 05 03...