Sweep Frequency Response Analyzer (SFRA) User Guide
3-12 72A-2570-01 Rev. K 07/2011
7. When you are satisfied with the test results:
a. Disconnect the test lead clamps from each other.
b. Disconnect the reference ground clamps from each other.
8. Go to “Step 2: Ground the Transformer” on page 3-12.
Step 2: Ground the Transformer
Each time the SFRA test leads are connected, disconnected, or moved, apply
temporary static-discharge grounds to:
• The bushings to which the SFRA test clamps will be applied
and
• Any bushings to which jumpers will be applied
To ground a transformer for SFRA testing:
1. Open the switches to de-energize the transformer and disconnect it from
the rest of the substation (Figure 3.18).
Figure 3.18 De-energized and Disconnected Transformer
2. Ground all conductor or bus still connected to the transformer terminals
outside of the transformer bushings and windings (Figure 3.19).
Figure 3.19 Grounded Transformer