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How do I replace my electrical panel?

2017 April 1

Dear Boat Doctor,

My 47-foot boat is 31 years old and is slowly showing her age. I have taken care of most of the systems, but I need to work on the main electrical panel. The panel is starting to mechanically fall apart, some of the breakers have failed and I ran out of capacity long ago. I have patched it over the years, but I think it’s time for a replacement. 

The panel is a long skinny configuration and I have not found a standard refit panel that fits. I really don’t want to have a custom panel built. How should I approach this?

Barry Ellsworth

Clearwater, Florida

Dear Barry,

I understand your pain. Breakers can get flaky over time, and lots of “good ideas” from multiple owners can make a mess of a panel. But replacement is a pretty straightforward job if you take your time to plan things well.

Let’s start with the panel itself. You may be stuck with a custom panel, but first take a look at the Blue Sea System’s 360 Panels (http://panelwizard.bluesea.com). These are modular panels made to your specifications. You identify the features you need and Blue Sea will build it for you in week. You don’t get the flexibility of a custom panel, but you can get close at a fraction of the cost and time.

Starting with a word of safety. Do not handle any live circuits, AC or DC.  The most important part of the refit is identifying every wire attached to the panel. Do your very best to track each wire down, label it and note the label, color and description on a spreadsheet. This ledger will be essential in putting the panel back together, and will be a valuable resource throughout the life of your boat.

With everything labeled, you can remove the old panel and plan for the mechanical installation of the new one. If you are lucky, the new panel will fit without much modification. If you need to make the panel cutout smaller, a sheet of ABS plastic or black acrylic can cover the old hole and support the new panel.

If the wires are in good shape and long enough, you can just attach them to the new panel. If not, you’ll need to add a terminal strip to terminate each wire and lead new jumpers out to the new panel.

I like to start with the supply wires to the new panel. The panel will need a DC main supply (typically a large red wire) and negative (smaller black wire) to allow any indicator lights or meters. The panel will also need the AC supply for all the AC circuits. With these connected, you can test any meters. With the panel powered off, work through each labeled wire, connecting to each new breaker. Dress each wire nicely around the panel and bundle the wires as you go.