Townhouses on right-of-way (ROW) in Northern Virginia near
a single-circuit 525 kV transmission line and single-circuit 34.5 kV
distribution line. The townhouses (in picture) are only 10 feet from
the 34.5 kV line and 60 feet from the 525 kV center conductor.
The Profile Plot (see below) shows magnetic field data
collected on a warm 94.6 degree (F) day. Levels in the townhouses were
8-12 mG with the peak of 17.4 mG recorded under the 525 kV transmission
line. It should be noted that during seasonal peak loads the magnetic
field levels could easily double or triple since the 525 kV is a high
current (triple-bundle) transmission line. Therefore, the levels within
the house could range under worst-case conditions from 16-24 mG to 32-48
mG.
Magnetic Field Management Solution:
Move the 34.5 kV distribution line 30 feet away from the
townhouses into the ROW.
Install an Active Magnetic Field Cancellation System around the townhouses
to (mitigate) reduce the magnetic fields from the transmission and distribution
lines to less than 2 mG within the townhouses.
