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.
To Next Page
Loading...
