Voltage Requirements

[Freestyle]

My beloved yacht club managed to build a brand new marina that only is delivering 208 volts. Not thinking they would do so I plugged in when it opened and did not check the voltage thereby wiping out all of my air conditioners in a month and a half.

I have been staying at a first world yacht club and getting 240 volts. All systems seem to really enjoy this voltage. Yesterday I was informed that my yacht club is trying to get up to 220 volts which they believe is sufficient.

Anyone have any thoughts as to whether my old boat can live with 220 volts? I have Cruisaire air conditioners and Magnum battery chargers. My guess is these are the two highest voltage demands.

Bruce

Freestyle
1986 62 CPMY (54 with 8 foot extension)
Tampa

 

[Glory]

How many volts from your generator?
I would say yes, maybe not ideal, but yes. I have stayed in marinas with less when traveling, sadly they sometimes seem to not understand the issue or care, and got by.

 

[Boatsb]

The standard and the drop are your concerns

Standard power is 120 per side. That's 240. If you start at 220 and have a drop your frying motors and cords.

Why is it now your place to accept the wrong power if they get it closer?

 

[tonytrakovich]

I have a 1989 65CPMY stretched to 78. I also have Cruisair split AC units. I have been in the Bahamas where I have had as little as 200 volts. The AC will run, but they hate it. Also fluorescent lights don't like to start, etc. Then, as boatsb said, you have to worry about the drop. You are measuring 208 at the power panel. If your cords are in disrepair or there are bad connections anywhere, you can get voltage drop and heat buildup. When I had low voltage in the Bahamas, I had to manage my loads by turning AC units off when cooking for example.

Not sure about your model, but my boat has polarization transformers. I talked to Hatteras and they said I can wire the transformers backwards to utilize the taps and make a voltage booster. I would have to put a switch in to change from normal to boost mode. If you have the transformers, I have the diagram from Hatteras. But remember if you boost the voltage 10%, you have 10% less current to play with. 50 amps turns to 45 amps.

 

[northshoreone]

I carry a Boost Transformer from Wards Marine...not cheap but gets the voltage back where it belongs when hooked to 208. Just remember they boost ALL voltage so check your meter before hooking up.

 

[carolinacoast]

I would start with code requirements and insurance requirements. Low voltage will cause fires just as well as high voltage.
Unlikely the Club wants liability for something that does not conform to ABYC standards or Electrical Buiding Code. An Insurance survey for their liabilty policy may be all of the leverage you need.


From somewhere on the internet:

Marinas
The National Fire Protection Association (NFPA) is a nonprofit organization that publishes a number of safety-related codes and
standards. These regulations are used by the fire service, industry, and state and local government as well as insurance and legal
parties. Here, we will discuss NFPA standards that are relevant to marinas. For more information and access to these codes and standards,
visit www.nfpa.org.
NFPA 303: Standard for Marinas and Boatyards has been published since 1940 and includes a number of important topics. Chapter
5 covers Electrical Wiring and Equipment. All marina and boatyard owners and operators should be familiar with and have access to
this document.
NFPA 70: National Electrical Code (NEC) is a very comprehensive electrical standard that is recognized and used throughout the
United States. Section 555 of the NEC covers specific electrical requirements for marinas and boatyards. Section 553 covers the
specifics for floating buildings, such as floating fuel docks, small marina offices, etc. Electricians who perform work in marinas and
boatyards should be familiar with the requirements of these two sections and marina owners and managers should discuss the
specifics when contracting for their services.
Some or all of NFPA 303 and NFPA 70 have been adopted as law by a number of states and are not merely recommendations. Some
states have recently adopted their own legislation for marinas and boatyards. Most of these new laws reference NFPA 303 and NFPA 70.
The NFPA and NEC are continually being revised. New in 2011, the NEC has a requirement under NEC 555.3 Ground Fault
Protection that states, “The main overcurrent protective device that feeds the marina shall have ground fault protection not exceeding
100mA. Ground protection of each individual circuit breaker or feeder circuit shall be permitted as a suitable alternative.”
Additionally, current NEC requires 100mA protection somewhere within the electrical system for all new installations.

 

[Pascal]

This is why I like visible and readable meters in a place where I ll see them. And yes always check before switching

220v is ok if stays around 220... If it drops then you re going to have issues

Low voltage is common in the Bahamas, when I see anything under 220 instal in genset which is usually cheaper anyway at transient rates in the Bahamas

 

[krush]

Your stuff is designed to be able to handle +/- 10%. Modern nominal is 120/240, though in the older days it may have been 110/220.

Regardless, 240 - 10% is 216volts.

I installed one of these on my RV and will be installing on the boat at some point (or something similar) soon. http://www.progressiveindustries.net/rv-power--surge-hardwired-c1p4w

 

[Boatsb]

But with amperage comes a voltage drop on longer runs. That can get the 220 below 210 in a hurry a do damage.

Starting low is not the best idea.

 

[kelpy]

Its sounds like your marina is using just one leg of a 240 VAC 3 phase wye transformer. You will need to boost it up but, as said before, you will lose some amperage in doing so.

 

[Pete]

Actually you get 208 volts by using two legs of three phase "240". Each leg is still 120 volts single phase, the problem is that any two legs of the 3 phase power will be 120 degrees out of phase instead of the 180 degrees you get with single/split phase power, which is the design point of your electrical system.

On the subject of cranking up the phase to phase voltage 12 volts to 220 volts, be mindful that this will increase the single phase voltage for those boats using 120 volt shore power, which may or may not be OK for those folks.

A couple of other thoughts. The Cruisairs on my Hatteras are rated at 230 volt input. This should allow operation down to 207 volts. Only problem with a nominal 208 volt supply, the power companies routinely drop their voltage by 5% on heavy load days, then you are in trouble before even discussing line loss at your marina.

So, what are the workarounds given the situation. First, if you have Cruisair electronics controls set the drop out voltage on each unit to 207 and prevent operation below the specs for the units. Second, implement the Hatteras transformer reversal, this will give you a 9% voltage boost. And a quick but not so pretty temp solution. If your boat has a 120 volt shore power input, use that and get a very limited amount of good power. A small amount of good power is superior to a large amount of bad power, especially on your checkbook. Depending on the power pedestals at your slip this may require an adapter to get 120 volt power.

Bottom line your marina took the less expensive wiring solution, apparently not realizing it was not compatible with the requirements of almost all boats. And to my knowledge there is not an easy fix that does right for both the 240 volt and 120 volts boats in a mixed environment.

Pete

 

[carolinacoast]

the best solution is to run proper 277/480 volt power and then a step down transformer for the 50 amp 240 pedestal sides
and 30 amp 120 volt for the other guys.

 

[Pete]

Looking for the simplest solution, with no rewire required, would be to swap out the line transformers for standard single phase 120/240 volt units like used for residential purposes and abandon one of the four wires in use for the three phase current install.

Yes, this does cut down on the total KWs available by about 30%, but 70% of good power beats 100% bad power every time.

Also, if the total KWs have to be the same, you run a new line or two to the pedestals closest to the transformers and let the longer runs remain in place.

That is how I would approach the problem. A great example of designing a system without understanding the requirements of your customers.

Pete