2. Magnetic field interference at 50 or 60 Hz must not exceed 40 milligauss RMS respectively
at the magnet location (refer to
)
3. The following equation can be used as a general guide in determining allowable current in
feeder lines at a given distance from the magnet isocenter:
a. For 1.5T LCC RD Magnet: I= (20X
2
)/S
b. I = Maximum allowable RMS single phase current (in amps) or maximum allowable RMS
line current (in amps) in three phase feeder lines
c. S = Separation (in meters) between single phase conductors or greatest separation
between three phase conductors
d. X = Minimum distance (in meters) from the feeder lines to isocenter of the magnet
Illustration 2-10: Magnet Allowable Milligauss vs. Line Frequency for AC Equipment
Chapter 7, Sample Calculation AC Power Equipment Minimum Distance
examples.
6.4 Non-MR System Equipment Sensitivity to Magnetic Fields
This section lists equipment known to be sensitive to high magnetic fields. Recommended limits
given are based on general MR site planning guidelines. Actual susceptibility of specific devices
SIGNA Voyager Pre-Installation
Direction 5680008–1EN, Revision 2
Chapter 2 General System Level
37
