Date: 28 September 2023. 8awg Selector
In the beginning, aka the
50 Amp 125/250 Volt Power Plug Wiring How-To
article, the dockside fellows and I were attempting to track down
why one leg of a yacht's power was not functioning. The critical
side is of course the one that is not working. The switch powering
the air-conditioners functions perfectly. The one supplying power to
the battery chargers for both 12-volt and 32-volt battery banks, along with the
refrigerator, staterooms, and main salon has zero voltage. Isolating
what part needed replacement is the next step in the troubleshooting process.
have 125/250 volts into the vessel. From the side deck inlets power
is fed to two switches. These switches are your basic On-Off-On,
labeled 1-Off-2. They are large
enough to accept a lot of 8 awg wires.
Selector #1 indicates shore power. Center
is Off. #2 is for power incoming from the onboard diesel Onan
This is the back of the switch:
Both the Port (on left) and Starboard (on right)
power distribution switches are
The switch on the left powers
the top air conditioning panel. The one on the right feeds power to
the bottom house panel.
issues the standard process is to start at the source.
Wherever the power stops is the problem.
This is the complete power panel for the vessel:
Each of the breakers are labeled. The top section is
powering the four air conditioners and circulation (cooling) pump aboard this yacht.
The first set of meters is for the air-conditioning
breakers. The meter on the
right shows 125 volts incoming. Thus we know the 1-off-2 switch on
the left functions.
To repeat, there are two switches above the 120
volt AC distribution panels. The one on the left (port
side) provides power to the Air Conditioners on this boat.
This is the Air Conditioning distribution panel. It
is powered by the 1-off-2 switch on the left (port) side.
The amperes meter at the top shows zero power being used. That
is because all of the air conditioners are turned off at present.
Travis ↓ is at the lower helm located in the
salon of the yacht. There is an air-conditioner on that level.
The ac unit for the main salon runs off that top ac
distribution panel via the main switch on the left.
We do have an anomaly: the bottom section of
the ac distribution panel is not receiving power. Was this due to a
broken connection between the shore inlet plug and the switch? To
test that the onboard Onan generator was started. The results
When checking the power panel the same results occurred:
This second distribution panel is
honestly the most critical of the two. The House breakers are for
important things like the galley, all three staterooms, a 12 volt
battery charger, the 32 volt battery charger, plus lights and more.
Frankly, this one powers the "house" whereas the other makes it cool
and comfortable aboard.
The 32-volt battery charger on that lower
distribution panel is vital for charging the 32-volt battery banks.
The owner does not have a portable 32v charger, so
having the house distribution panel functional is important.
I wrote about replacing those 32-volt batteries in the
St. Pete's Electro Battery article.
The AIR CONDITIONING BREAKERS
↓ is shown on the left.
To the right is the
↓ HOUSE BREAKERS SWITCH.
Aboard this larger vessel are four
air conditioners which provide zone cooling. Thus the need for a
separate power panel for those AC units. The House is basically
everything else running on standard *125 volt power, including the
refrigerator/freezer, water heater, staterooms and heads, etc.
Though in this article we are using the term 125v, actually I use
this interchangeably with 110v and 120v. This is your standard house
power. Indeed 125 volts does reach the vessel. Aboard Seaweed I see
118v or so. Everything electric works fine.
The back of the distribution panel is a mass of
Notes are also on the bulkhead regarding power
Side Note for vessel owners:
It is ALWAYS a great idea to make notes in an easy to
see place on your equipment. One of the best implementations
of this is described in the
Life onboard Lily Maria
There are a lot of wires aboard a
larger yacht. It is complex.
The top AIR CONDITIONING
↓ has 125 volts of power, thus
the switch on the top left works.
Because the bottom HOUSE BREAKER PANEL
↓ has zero incoming power
I believe the switch on the top right is broken.
This is the back side of the selector switches shown
As a reminder, this is the back side... thus the
problem switch is on the LEFT,
versus the right. There are a boat-load of 8awg wires feeding into
The proper way to verify that the bad switch is indeed not
functioning would be to remove the wires from both switches and swap
them. Quite frankly, that looks incredibly intimidating to me. All
testing has proven power gets to both switches (verified via
multimeter) however nothing passes though to the House Distribution
panel from that second switch.
So, the decision was made. Replace this switch:
Here is the problem: The switch was
manufactured in Austria. It was purchased some 20-odd years ago. The
numbers do not match to anything I have seen online. That said, I am
not great at searching. Can you help with a source to purchase a
The numbers written on the back of
that switch are:
C63 63 amp.
50hp 600 V 3ph
What say the
experts? Is there a work-around we have not considered? All of us
here on the docks would appreciate your ideas. If you know where to
buy a replacement, that would be ideal. I am hoping one of my online
friends can help. Thanks!
That's it from the water. I thank you for reading.
Do you know where a replacement switch capable of
accepting a boat-load of 8 gauge wires can be purchased?
And, what does that circle gizmo do on those wires? Is it to prevent radio
Regarding the Comments Section,
found at the end of every article:
Before you type in each block be
sure to hit the backspace key. Coding inserts a space in every box.
Your email address will come back as malformed unless you remove
that space. (You don't have to include your email address.)
The capcha is case sensitive.
In the Bilges,
Waters of Idalia ~
Previous Post ...
... Next Post
~ coming soon