Isolation Transformers & AC Wiring

I have been running a 30 Amp shore power circuit though a 120V-120V isolation transformer for several years now.  My zinc anodes now seem to last forever.  I purchased a second isolation transformer (XFMR 2)  capable of being stepped up or down 120/240V to 120/240V in any of four combinations.  This idea being I can wire it for European power when I travel over there.  However, while I mounted this transformer, I did not wire in it because I was debating moving both of these transformers.  I may still do that, but I felt it was important to get this XMFR 2 working now.  The wiring from the deck shore power connector was brought to Isolation XFMR 2.  Tonight I wired the feed from the panel to the XFMR 2.   I reconfigured the AC Power panel to split it so that each shore power feeds a separate bus.  All I need are a few nuts and bolts to connect the transformer itself.  I will also have to make up four jumpers to configure XMFR 2 to be 120V-120V service.  And, I will need to hook up a 10 gauge ground wire from the case of XTFR 2 to my bronze yacht ground plate.

For this winter, I like the idea of having one heater on each circuit.  Not really necessary, but I can't open up and inspect the power stanchions that provide service on the dock.  Two circuits would give me some redundancy for heating as I plan to leave the fresh water system in service, while winterizing the motor.  I don't want it to freeze.  If I want to do some fiberglass work this winter, I will be able to heat up the boat enough to cure that work in a reasonable amount of time.

Most of the time when sailing, you are in the wind so air conditioning is not needed.
This dockside power will allow me to dedicate one leg to supply to a couple of air conditioners on the boat.  There is nothing worse than being stuck on-board in a windless harbor on an unbearable, hot and humid day.  It is like being in an oven.  If the other option is to spend $250 for a room per night, it would not take long to pay the modest cost of several yacht air conditioners.  And no need to pay cab fare to reach the refuge of air conditioning.

It is a rather nice power system I have.  My boat has both legs fed into the boat through isolation transformers which are expensive, but do a great job of protecting the boat from stray currents that cause galvanic corrosion.  Since I started using the first isolation transformer, I've reduced galvanic corrosion to next to nothing. 

Most boats have weak systems that require sacrificial zinc anodes that wear away quickly.  Mine last more than a year.   So I will have 60 Amps of power on the boat while dockside!  And none of it will cause galvanic corrosion.


I started using German "Wago" brand wiring connectors which are spring loaded and can easily be secured to a wall, easily modified--simple and strong.  They are a bit pricey but clearly so much easier to use and service, I will upgrade to these throughout the boat.  My present system has many screws that I often drop and are a pain in the ass to hook up.  I want to add these Wago connectors in-between my panel and the loads. They easy to use at the dock and that much easier to modify or fix underway in a bouncing sea-way.  Also, they allow one breaker to split out to more than one circuit and even provide fuses for the branch circuits.  These Wago DIN Rail connectors, are things I plan to use throughout ECHO and will reducing the number of wires at the panel substantially.


So I gave some thought to how I want to rewire my AC circuits.  Shore 2 has five 15A circuits and is directly wired.  Shore 1 has seven 15A circuits and is feed through a 3000 Watt Inverter.

Shore 1                      Shore 2

1. Computer              1.  AC 1
2. Galley                   2.  AC 2
3. Deck Outlets         3.  Vacuum
4. Microwave            4.  Charger 2
5. Outlets                  5.  Outlets
6. Video                           
7. Water Heater

Notes:

Video = Future Satellite Dish and CCTV.  I plan to buy a DC TV, however, I might need AC for an amplifier or some item that only runs on AC.

I like the idea of a central vacuum system.  It would get a piece of equipment that I use often, my vacuum, out of the way.  If these are available as wet dry vac's that would be perfect, especially if it could be vented overboard.

Charger 2 charges the starter battery.