Question re Shore Power

[GJD]

What is the 'ideal' shore power service for us on our 53my?

One 50 amp cable? Two 50 amp cables?

Getting rigged up on the new boat and this is one of our first projects.

Thanks!

[Dave Phipps]

This is an appropriate concern given the usual low voltage at many marinas...you'll want to make sure you have adequate voltage or you'll end up damaging airconditioners, refrigerators, and ice makers over time. One 50 amp 125/250 volt shorepower cord (4 pin connector) should normally carry all the power you'll need, provided you have a 240 volt supply. Because the cost of wiring for 240 is prohibitive for many marinas, they use smaller gage wire designed to carry something less, about 220 volts. However the actual voltage delivered may be something even less, say 190 to 205! While most older components will run on this power, damage will occur below about 208 volts. Newer components often have built in drop outs if the voltage goes below a certain value for a few minutes to protect the component.)

If this is the case in your marina, you'll need to buy a smaller transformer for your slip, pluged into the dockside 50A shorepower recepticle, capable of boosting the voltage to 240 volts. Your shorepower cord can then be connected directly to the transformer. Note that amperage will drop as the voltage is increased, but again you'll seldom need all 50 amps simultaneously.

There is one other option, more expensive, and that is to upgrade the boats internal isolation transformers (located behind the generator) with a kit from Wards Electric. The Hatteras technical support line can give you Ward's number in Florida, and provide you more details. This isolation "boost" kit modifies your isolation transformers and will allow you to plug into low power at most any marina, and the boat will then produce it's own 240 volt supply from the 220 marina supply. There is some wiring to be done with the kit....I haven't any personal experience with this, but maybe someone here has and can speak to it...

[Pete]

"Because the cost of wiring for 240 is prohibitive for many marinas, they use smaller gage wire designed to carry something less, about 220 volts."

I believe the savings come from installing "fewer" wires, not smaller guage wire. Amps determine the wire guage, voltage determines insulation properties.

Pete

[SKYCHENEY]

Greg,

Your "newer" 53 has the same wiring setup as mine. Here is what I do. I use 2-50a cords whenever possible. I select one for the air conditioning panel (panel 2) and the other for panels 1 and 3. This makes use of both isolation transformers and lessens the total load that would otherwise be put through just one transformer. If the dock does not provide access to 2-50a plugs, then I either run one or try to run the second cord using a smart Y and connecting it to 2-30a plugs.

The great thing about running 2 50a cords is that you never have to be concerned about how much you are drawing. You don't even have to think about it. You'll have all of the power that you'll ever need.

[Dave Phipps]

Sky,

You'te lucky to have access to two 30A or two 50A recepticles...it's just "one per customer" here. If you have two, you're living in power heaven!

Dave

[Dave Phipps]

Pete,

You are correct; there is one less wire. The electrical engineer we had look at our problem also stated that the wire gauge was too small in our case for a 240 volt application....not sure what he was referring to...code or insulation...

Dave

[krush]

Pete,

You are correct; there is one less wire. The electrical engineer we had look at our problem also stated that the wire gauge was too small in our case for a 240 volt application....not sure what he was referring to...code or insulation...

Dave

silly engineers...

[thoward]

We have no issues running 1 50A service for our 60C.

[HAT-70]

When you talk about a "smart" Y what do you mean, I know about a Y adapter but what is a "smart" Y?

[SKYCHENEY]

A smart Y has a box attached that insures that you are plugged into opposite phases. Each 30a socket must be on the opposing phase so that you can get 240v when you hook to them.