Mainship 40 Trawler Single - Page 80

M
ainship 40 Trawler Sin
g
le & Twin • DC Electric S
y
stems
7.4
of
y
ellow
(
ne
g
ative
)
wires attached. All electrical circuits
require a
g
round, so all
g
rounds are
j
oined in sections at
“g
roundin
g
blocks”.
You will notice on the ri
g
ht hand side of the
g
roundin
g
block pictured a
g
reen wire attached, this is part o
f
the
“
Bondin
g
S
y
stem”.
The purpose of the bondin
g
s
y
stem is to protect
y
ou
r
boat’s underwater components
f
rom electrol
y
sis or
g
al-
vanic corrosion. Examples of underwater components
would be the
p
ro
p
ellers,
p
ro
p
eller shafts, rudders, o
r
e
n
g
ine
/
g
enerator and seawater intake valves
.
El
ectro
ly
s
i
s an
d
g
a
l
van
i
c corros
i
on occurs pr
i
mar
ily
i
n
s
alt water but can occur to a lesser de
g
ree in
f
resh water.
Sa
lt w
a
t
e
r
a
ll
o
w
s
e
l
ec
tri
c
cu
rr
e
nt t
o
fl
o
w fr
o
m
a
n
od
i
c
t
o
c
athodic material. An
y
two metals from two components
and their relative position in the
g
alvanic ratin
g
table
will determine which metal loses material
(
anode
)
and
which metal remains lar
g
el
y
undisturbed
(
cathode
)
. The
distance apart in the
g
alvanic table o
f
the two metals
de
t
e
rmin
es
th
e
r
a
t
e
o
f w
ea
r.
To help prevent corrosion, sacri
f
icial zinc anodes are
wired to the underwater components of
y
our boat, such
as the
p
ro
p
eller shafts and rudders, then connected to a
lar
g
e sacri
f
icial zinc anode plate
(f
i
g
. 7.5
)
attached to the
u
n
de
rw
a
t
e
r
a
r
ea
of
th
e
tr
a
n
so
m
.
Fig
ure 7.5
Zi
nc
Pl
at
e
The sacrificial zinc anodes are considerabl
y
easier and
c
hea
p
er to re
p
lace and their deterioration will not affect
the per
f
ormance o
f
y
our boat as would the deterioration
of an
y
underwater components.
The bondin
g
s
y
stem is a network o
f
wires
(
color coded
g
reen
)
that are connected to all metallic underwater com-
p
onents within the interior of the hull, which makes them
one unit
f
or electrical current purposes. This network o
f
wir
es
i
s
th
e
n
a
tt
ac
h
ed
t
o
th
e
sac
ri
f
i
c
i
a
l zin
c
a
n
ode
l
oca
t-
e
d on the transom, which allows corrosion of the anode
but prevents corrosion o
f
the underwater components.
General maintenance of the bondin
g
s
y
stem consists o
f
y
earl
y
replacement of the sacrificial anodes. This should
be completed durin
g
the sprin
g
launch procedure
f
o
r
e
xample. The anode ma
y
require more frequent replace-
ment,
d
epen
di
n
g
on
y
our
d
oc
ki
n
g
l
ocat
i
on an
d
t
h
e
l
en
g
t
h
o
f
y
our boatin
g
season. I
f
possible, check the anode
f
o
r
e
xcessive corrosion midwa
y
throu
g
h
y
our boatin
g
sea-
s
on. If excessive corrosion is noted, have
y
our dealer o
r
a competent technician replace the sacri
f
icial zinc anode.
P
eriodicall
y
check the wirin
g
connections to make sure
the
y
are ti
g
ht and free of corrosion. Ti
g
hten and clean
c
onnections as necessar
y.
Important: DO NOT PAINT any part of the sacrificial zinc
anode as it will retard the flow of electric current through
them and render them ineffective.
7.1.7 Generator
Althou
g
h technicall
y
the
g
enerator is part of the AC
Sy
stem, because it supplies A
C
power. The startin
g
o
f
the
g
enerator requires DC power, the
g
enerator startin
g
receives
p
ower from the batteries in the lazarette area.
The
g
enerator supplies 120 volt 60 hz AC power fo
r
operat
i
n
g
d
ev
i
ces an
d
equ
i
pment contro
ll
e
d
t
h
rou
gh
t
h
e
A
C
Distrbution Panel.
When the
g
enerator indicatin
g
li
g
ht is on and the
g
enera-
tor breakers are
O
N, A
C
power is supplied to both the
g
enerator and AC control panel devices and equipment.
The
O
N li
g
ht at the A
C
Distribution Panel is
ill
u
min
a
t
ed
.
The slide bar prevents power
f
rom bein
g
supplied
f
rom
s
hore power when usin
g
the
g
enerator
.
R
e
f
er to the
“O
peration and Procedures” part o
f
the A
C
Electric section
f
or in
f
ormation on startin
g
the
g
enerator.
7.1.8 DC Distribution Panel
The DC Distribution Panel, located in the starboard aft
s
ide o
f
the salon controls D
C
current throu
g
hout the boat.
Fi
g
ure 7.8 lists the breakers and circuits the
y
protect.
Besides the batter
y
selector switches
y
ou must en
g
a
g
e
the D
C
Main at the MDP to provide D
C
power to the
respect
i
ve components or s
y
stems.