S9407-AB-HBK-010 Datasheet, PDF (257/276 Pages) Glenair, Inc. – HANDBOOK OF SHIPBOARD ELECTROMAGNETIC SHIELDING PRACTICES

S9407-AB-HBK-010, Rev. 2
Table F-2. Conduit On Both Cables
Cable/Conduit
Categorization
S1-X
S2-X
S4-X
Example: S4-4
Categorization with
DC Fields
S1-(X-2)
S2-(X-2)
S4-(X-2)
S4-2
F-4 DISTANCE FROM DC GENERATING COILS
When attempting to run cables in flexible shielding conduit close to dc generating coils a minimum
spacing requirement shall be met. This must be done in order to ensure that the maximum dc magnetic
field levels remain at or below 20 gauss. Table F-3 indicates the minimum spacing from dc generating
coils needed to ensure that the dc magnetic fields do not exceed 20 gauss. These spacing requirements
are in addition to the requirements of table F-1, table F-2, and Section 6.
Table F-3. Minimum Required Spacing From dc Generating Coils
NI (ampere-turns)
1000
750
500
250
Minimum Distance
(inches)
4.0
3.0
2.0
1.0
For ampere-turn values different from those listed in table F-3 the equation shown below should
be used to determine actual spacing requirements:
where:
r = (0.004)NI inches
I = Current in amps
N = Number of turns
F-2