Download Optima MR450w Preinstallation Manual

Optima MR450w Preinstallation Manual
Direction 5670001, Revision 3.0
GE Healthcare
7.3 Electrical Current
1. Electrical current in high voltage power lines, transformers, motors, or generators near the
magnet may affect magnetic field homogeneity
2. Magnetic field interference at 50 or 60 Hz must not exceed 40 milligauss RMS respectively at
the magnet location (refer to Illustration 2-10)
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 Magnet: I= (20X2)/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
Refer to Chapter 7, Sample Calculation AC Power Equipment Minimum Distance for additional
examples.
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7 MR Suite Magnetic Field Specifications