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I have no hard wired shore power system on my 1980 CD27. Currently I have a yellow West Marine 30 amp shore power line coming from the dock to my lazarette, where it terminates with a 30 Amp to 20 Amp adapter into which I have plugged an outside 4 outlet extension cord to run my radio/TV/ computer/cooler.
I bought a 30 AMP fixture from WM to go into the side of the cabin or lazarette. But, they really seemed to know nothing about what comes next. I have done home AC wiring, but has anyone actually installed an AC system on the boat from scratch? What do I need and where can I get it? Is there a breaker box for 30 AMPS? I can't seem to find one. Once passed the breaker box issue can I set up two 15 Amp circuits (one to run down each side of my CD 27) with two outlet interrupter style boxs forward and aft?
I have wired shore power a few times and never had too much trouble finding stuff. All of the parts came from hamilton marine.
From your 30A plug, you should run 10AWG wires to an AC panel. I believe that the panels I have used are from Blue Sea. The wiring is similar to a house panel using the top slots for the main breakers. I particularly like the panels which have an indicator light showing which circuits are on. You can also get panels with a light indicating reversed polarity which is helpful. It is shocking how many docks have the polarity reversed. I have always bought the flush mount panels and either flush mounted them on a hinged piece of cabinetry or mounted them into a junction box which I cut the front out of.
I just went onto the hamilton website and searched for AC electrical panel and got several results which would work. West marine's website appears to have some panels as well. They also have a few articles on how to wire it at in their west advisor section.
You're right on the money with what you say. Early last summer we were sailing on Mike Ritenour's La Vida across the Erie Canal and going down the Hudson River to NYC. We overnighted at Kingston and tied up to pier in a marina. We plugged in to the shore power and sadly discovered that it was reverse polarized. Not good.
I'd like to add to your advice. When using shore power for AC use on the boat, check for earth ground as well as the hot and neutral supplys. It goes without saying to check for correct polarity.
NEUTRAL IS NOT EARTH GROUND. Somewhere upstream they should be common to each other, but it is not a given.
I am a firm believer in ground fault interupter (GFI) governed circuits. Some panels are provided with GFI circuit breakers. Older panels may only have fuse protected circuits or maybe just plain circuit breakers without GFI protection.
If you don't have GFI protection in the AC panel, You can still wire to local AC receptacles. At the first receptacle, install a GFI receptacle. Then continue on to the next receptacles in a daisy chain order. The first GFI receptacle will provide coverage for the nexr receptacles down stream from it. I believe that four is the total of receptacles allowed to be wired in this fashion.
One bonus when wiring for AC power. You are absolved from doing the math when figuring distance both to and from the panel and using larger conductors to allow for that pesky voltage drop (VD) that is associated with DC power.
When using 110/220 volts, VD on our boats is rather insignificant and a nonfactor.
Has anyone found a GFI breaker that could be wired into the feed before the main panel?
I am thinking about a single, 30 AMP, double pole, breaker that would be enclosed in it's own waterproof housing and be mounted right after the shore power connection in the cockpit locker.
My thinking is that it would protect all of the circuts from a ground fault and in addition it would provide overload protection to the feed wire going to your main AC distribution panel.
There is much potential for problems with the AC wiring before it reaches a breaker in the setups we have on our boats. I suppose it is no different than the way a house is wired except for the fact that a house isn't moving around all of the time and you are usually not throwing things into the area where the main service wires run to your breaker panel.
When I wired my house I put GFI beakers in the panel instead of using GFI recepticals where they were required, Steve.
Paneltronics makes a nice AC panel with 4 circuits and a reverse polarity light. Prewired for breakers.
I like the GFI outlets with the indicator light that lets you know it's powered.
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Last edited by Ron M. on Feb 11th, '11, 06:12, edited 1 time in total.
Something I would add to your plan is to install a Galvanic Isolator between the Main breaker and the 30 amp inlet. This will not affect AC safety, but is designed to prevent stray DC from contributing to electrolysis. http://www.yandina.com/galvanicIsolator.htm
For a polarity tester there is a cheap way out. Pick up a plug in circuit tester and simply plug it into an outlet. Make sure your wiring is correct for polarity first. Leave the tester plugged in all the time as a double check that you are getting power. http://www.amazon.com/Electrical-Recept ... B0012DHVQ0
As to the double pole GFCI breaker, you can do it, but simply putting GFCI outlets in is just as effective and a lot cheaper.
One more thought that has not been covered. Do not use Romex from the hardware store. Use tinned stranded wire for the system. It costs more, but solid wire has very few places on a boat due to vibration problems. The tinned stranded wire can be bought at most marine stores in a three conductor cable.
I have a question, when I tried to use shore power my red polarity light came on . Where should I start looking for the problem?
1981 Cape Dory 30.
Richard
I would suggest first checking the shore power source. If that proves to be correct, then work downstream on the boats electrical system.
Polarity can be checked in several ways. If it is a conventional 15 Amp, AC supply, there is a plug-in unit that has different colored lights that will tell you what the polarity status is.
You can test the polarity of larger amp services with a multimeter set on (250 voltage).
You have to check the plug configuration on the boat's power supply cord. Different shore power supply amperages have different plug configurations. Adapters can be purchased or made up to comply with the various amperage configurations.
My original factory panel has a reverse polarity indicator light with a togle test switch to ensure the indicator light is functional. I only use shore power when aboard and never leave the cord attached when away from the boat. I am extremely cautious around electricity and consider myself ignorant of all but the basics. I put my faith in the polarity indicator. Am I playing it safe or are other precautions preferred?
Be certain your ground,(boat side) for AC is correct and functional. Once you determine the possibilities mentioned in this thread are ok, and the problem persists you may have a positive and a neutral crossed somewhere in the line.
As OJ mentioned, start with AC feed on shore and test every connection in the line.
________ No2 vaporizer
Last edited by Ron M. on Feb 11th, '11, 06:13, edited 1 time in total.
11.5.3.1. The system shall be polarized as
defined in E- 11.4
11.5.3.2. A grounded neutral system is required.
The neutral for AC power sources shall be grounded
only at the following points:
11.5.3.2.1. The shore power neutral is
grounded through the shore power cable and shall not
be grounded on board the boat.
11.5.3.3. The main AC system grounding bus
shall be connected to
11.5.3.3.1. the engine negative terminal or the
DC main negative bus on grounded DC systems, or
11.5.3.3.2. the boat’s DC grounding bus in
installations using ungrounded DC electrical systems.
11.5.3.4. In AC circuit, all current carrying
conductors and the grounding conductor shall be run
together in the same cable, bundle or raceway.
11.5.3.5. There shall be no switch or overcurrent
protection device in the AC grounding (green)
conductor.
11.5.3.6. When more than one shore power inlet
is used, the shore power neutrals shall not be
connected together on board the boat.
11.5.3.7. Individual circuits shall not be capable
of being energized by more than one source of
electrical power at a time. Each shore power inlet,
generator, or inverter is a separate source of electrical
power.
11.5.3.7.1. The transfer from one power
source circuit to another shall be made by a means that
opens all current-carrying conductors, including
neutrals, before closing the alternate source circuit,
and prevents arc-over between sources.
11.5.3.7.2. A means for disconnecting all
power sources from the load shall be provided at the
same location.
EXCEPTION: Exception to E-11.5.3.7 and its
subsections: The grounded neutral from a
polarization transformer, isolation transformer,
generator or inverter may be permanently connected
to the same main AC grounding bus (See E-11.7.2.2,
DIAGRAM 5 ) and is not required to be switched.
11.5.3.8. Energized parts of electrical equipment
shall be guarded against accidental contact by the use
of enclosures or other protective means that shall not
be used for non-electrical equipment.
11.5.3.8.1. Access to energized parts of the
electrical system shall require the use of hand tools.
11.7.2. FOR AC SYSTEMS
11.7.2.1. SHORE POWER
11.7.2.1.1. SHORE POWER SUPPLY
11.7.2.1.1.1. Power Inlet - The receptacle, or
receptacles, installed to receive a connecting cable to
carry AC shore power aboard shall be a male type
connector.
11.7.2.1.1.1.1. Power inlets installed in locations
subject to rain, spray, or splash shall be weatherproof
whether or not in use.
11.7.2.1.1.1.2. Power inlets installed in areas
subject to flooding or momentary submersion shall be
of a watertight design whether or not in use.
11.7.2.1.1.1.3. Metallic power inlets installed on
metallic or carbon fiber reinforced boats using an
isolation transformer or a galvanic isolator shall be
insulated from metallic structure and components. On
non-metallic boats using an isolation transformer or a
galvanic isolator the power inlet shall be insulated
from metallic components connected to the boat's
ground.
11.7.2.1.1.2. Shore Power Cable – On each boat
equipped with an AC shore power system, a shore
power cable that contains the conductors for the power
circuit and a grounding (green) conductor shall be
provided.
11.7.2.1.1.2.1. Except where the shore power
cable is permanently connected to the boat, the boat
end of this cable shall be terminated with a locking
and grounding female type connector to match the
boat power inlet. (See FIGURE 13 and FIGURE 14 .)
11.7.2.1.1.2.2. The shore power cable shall be
flexible cord with the minimum properties of Type
SOW, STW, STOW, SEOW, or STOOW, and shall be
suitable for outdoor use. The shore connection end of
this cable shall be fitted with a locking and grounding
type plug with the required number of poles and shall
comply with Article 555 of the National Electrical code.
11.7.2.2. APPLICATION OF TYPES OF
SHORE POWER CIRCUITS
11.7.2.2.1. Single Phase 120-Volt Systems
with Shore-Grounded (White) Neutral Conductor and
Grounding (Green) Conductor.
11.7.2.2.1.1. The shore grounded (white) and
ungrounded shore current carrying conductors are
connected from the shore power inlet to the boat's AC
electrical system through an overcurrent protection
device that simultaneously opens both current carrying
conductors. Fuses shall not be used instead of
simultaneous trip devices. (See E-11.12.2.9.2.)
11.7.2.2.1.2. Neither the shore grounded
(white) neutral conductor nor the ungrounded current
carrying conductors shall be grounded on the boat.
(See E-11.5.3.2.1.)
11.7.2.2.1.3. When more than one shore power
inlet is used, the shore power neutrals shall not be
connected together on the boat. (See E-11.5.3.6.)
11.7.2.2.1.4. The shore-grounding (green)
conductor is connected, without interposing switches
or overcurrent protection devices (See E-11.5.3.5.),
from the shore power inlet to11.7.2.2.1.4.1. an optional galvanic isolator, and then to
11.7.2.2.1.4.2. all non-current carrying parts of
the boat’s AC electrical system, including
11.7.2.2.1.4.3. the engine negative terminal or its
bus.
11.7.2.2.1.5. If an optional galvanic isolator is
used, the shell of a metallic shore power inlet shall be
electrically insulated from the boat.
11.7.2.2.1.6. If the boat's AC electrical system
includes branch circuit breakers, the branch circuit
breakers shall simultaneously open both current
carrying conductors unless a polarity indicating device
is provided. (See E-11.12.2.6.1 Exception.)
11.7.2.2.1.7. Polarization of conductors must be
observed in all circuits (see DIAGRAM 1, DIAGRAM
2, and DIAGRAM 3)
11.12.2.6. Branch Circuits - Each ungrounded
conductor of a branch circuit shall be provided with
overcurrent protection at the point of connection to the
panelboard bus. Each circuit breaker or fuse used for
this purpose shall be rated not to exceed the current
rating of the smallest conductor between the fuse or
circuit breaker and the load.
11.12.2.6.1. For boats wired with 120 volt,
single-phase systems, branch circuit breakers shall
simultaneously open both current-carrying conductors.
Fuses shall not be used. (See E-11.7.2.2.1, DIAGRAM
1, and DIAGRAM 2.)
EXCEPTION: Branch circuit breakers may open
only the ungrounded current carrying conductor if
the AC system on the boat is equipped with a polarity
indicator, or transformer.
11.16.1.3.1. Conductors shall have a minimum
rating of 600 volts.
11.16.1.3.2. Flexible cords shall have a
minimum rating of 300 volts.
11.16.1.3.3. The temperature rating of
conductors and flexible cords shall be at least 140oF
(60oC) dry.
11.16.1.3.4. In engine spaces,
11.16.1.3.4.1. the insulation shall be oil resistant,
and
11.16.1.3.4.2. the temperature rating shall be at
least 167oF (75°C) dry.
NOTE: Conductor rating temperatures refer to the
insulation maximum operating temperature of the
conductors.
11.16.1.3.5. All conductors and flexible cords
shall meet the flame retardant and moisture resistant
requirements of UL 83, Thermoplastic-Insulated
Wires and Cables.
11.16.1.3.6. All conductors and flexible cords
shall meet the requirements of the applicable standards
of Underwriters Laboratories Inc.
11.16.1.3.7. Conductors and flexible cords shall be stranded copper according to TABLE XII.
11.16.4.3.1. All connections normally carrying
current shall be made in enclosures to protect against
shock hazards. "
Great Info! However, someone on my dock said I should not be preparing to set up for 30 AMP. because most marina's today are giving 50 or 100 AMP service. What will probably serve my needs best? Is there an advantage to installing bigger service?
I'm trying to figure our what do you use on your CD 27 that would create a demand for 50A or 100A supply.
If it should prove to be the case that the marina does only supply large amp services, you can circumvent that problem with the use of store bought or DIY home made adapters to reduce the supply to your particular boat's service requirements.
In short, install an AC installation according to your present and future power projections. Then reduce the large shore power supply down to your size service with the use of a cable reducer.
Example: 50A (shore power service) down to 30A (your size service)
Good luck,
O J
Last edited by Oswego John on Dec 4th, '09, 15:55, edited 1 time in total.
I would wire the boat for 30A. A 50A shore power cable is almost unmanageable. 30A will let you run an AC unit and your battery chargers at the same time, that seems like plenty to me. I worked on a 92' schooner that only plugged into 20A service at its home dock and it was plenty.
For a few bucks, you can go to the hardware store and buy all the ends you might need and a bit of wire and make all of the adapters.
Having returned recently from a sail down the east coast and staying at a number of marinas between Ma. and Fl. every slip we took had 30A shore power available, some supplied 50A as well. I didn't inquire about greater service. Some charged an additional 10 bucks for electricity, at others it was included in the per/ft. fee. I can't imagine what a cruising sailboat would have to require 100 amps . I suppose if one has refrigeration, electric heat, color tv etc.,etc. 50A might be necessary. My boat is wired for 30A and that has been more than adequate.
________ Love Help
Last edited by Ron M. on Mar 8th, '11, 14:00, edited 1 time in total.
I can't seem to find one. Once passed the breaker box issue can I set up two 15 Amp circuits (one to run down each side of my CD 27) with two outlet interrupter style boxs forward and aft?
