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240v Wiring

We fixed the power input socket inside the port side cockpit locker on the
forward bulkhead and the galvanic isolator close to it. The Consumer unit
was fixed in the aft cabin on the other side of the same bulkhead with the
Galvanic Indicator LED just next to the Consumer unit. All the negatives
for the peripherals were wired to the negative bus, and all the earths for
the peripherals were wired to the earth bus. All the positives for the
sockets were wired to the first MCB, the positive for the immersion to the
second MCB and the positive for the battery charger will be wired to the
third MCB.
I have no connection with Safeshore Marine, I just found them when
researching Galvanic Isolators.

Galvanic Isolator. Safeshore Marine also provide an easy to understand
description of the need for galvanic isolation, here The unit we
used also alerts the consumer to any fault by lighting up one or more
LEDs, and is complete with a method of checking the LEDs.

RCD = Residual Current Device. This item replaces what used to be called
the earth leakage trip, it does a similar job, but is much more sensitive. It
works by sensing the currents in the positive, negative and earth wires and
when activated cuts both positive and negative connections for the whole
of the boat’s 240v system.

MCB = Miniature Circuit Breakers. These are excess current circuit
breakers, which are also very sensitive with standardised current ratings
and tripping characteristics. When tripped these cut the positive supply to
the appropriate part of the system.

George Llewellin

Page 49