For multiple amplifi er installations where distribution blocks are used, each amplifi er should have its proper-rated
fuse, or breaker, installed between the amplifi er and the distribution block within seven inches of the block, or on
the distribution block if it provides for fusing. The primary power wire should also be fused between the battery
and distribution block, within seven inches of the battery's B+ terminal, with a fuse or breaker rated at least to the
sum of the individual amplifi er's fuse values, but not to exceed 1.5-times the sum of the individual fuse values
(not to exceed the ampacity of the thermal insulation of the wiring as shown in U.S.C.G. CFR33 183.425, Table
5). See the diagram below.
NOTE: Seven inches is the standard distance under U.S. Coast Guard CFR33 for placement of fuses or
breakers as required by law for new boat manufacturing. We recommend trying to adhere to this standard in a
consumer installation. Failure to do so does not mean you are breaking the law, but it does put the safety of your
boat and passengers at risk in the event of a power wire short circuit.
7"
(18cm)
external fuse
to amplifi er
2013 KXM 400.4 Rev E.indd 4
2013 KXM 400.4 Rev E.indd 4
external fuse
power distribution block
7"
(18cm)
external fuse
to amplifi er
7"
(18cm)
12V
battery
4
2/19/2013 3:23:01 PM
2/19/2013 3:23:01 PM