Elements of a Galvanic
Boat owners are inherently independent,
drawn to the freedom and challenges of being on the water. Marinas, on
the otherhand, not only protect and constrain
a boat, but also obligate the boat owners to adhere to certain standards for
the collectivegood of all the slip holders. Nowhere is this more important
than balancing the freedom of the boat owners to outfit and maintain the systems
on their boats and the need of the marina to minimize stray DC electric currents,
which contribute to corrosion. Also, there is the problem of AC current leakage
from the shore power source or from the vessels through the dock and on board
the vessels to prevent potential shock and fire hazards.
Located on Coon Key in Sarasota, Fla., the Sarasota Yacht Club (SYC) has embarked on a comprehensive program to assure its members that they have a safe and reliable electrical system in their marina. Th ere are power boats, sail boats, new boats and old boats in the SYC marina’s 104 boat slips. Acting with foresight, they addressed the electrical system in its totality by testing and then taking the necessary action to bring every element of the system up to code and the recommended ABYC (American Boat and Yacht Council) standards and NFPA (National Fire Protection Association) guidelines. Driven to succeed, the team included the SYC Board of Directors, management and members working with the surveyor and electricians.
First, we defined the marina electrical
system to be from the shore based main distribution panel to every
electrical element, including all pedestals,
light fixtures, fuel pumps, the dock master’s office, all junction
boxes, the TV cable system, all the shore power cord and all the boats
in the marina. Then, a qualified electrical contractor, RAM Electric Inc.,
was selected to conduct a thorough inspection and correction of any necessary
deficiencies of the entire dockside electric system. RAM Electric proceeded
Once convinced of the integrity of the electric system and assured that it met all codes, a contract was awarded to Captain Stanley G. Konz of Maritime Surveying, LLC. Th e fi rst task was to verify the integrity of the dockside electric system. Voltages and current availability were checked at every pedestal, receptacle, outlet, light fi xture and fuel pump system on the dock.
After it was determined that the dockside electrical system met the
standards, the following detailed tests were performed. Included in the
The readings that I took included:
The objective was to determine the presence of any AC current leakage
and the degree of galvanic corrosion protection. The standards employed
were the ABYC and NFPA guidelines. Th e following test apparatus was
used throughout the process:
THE DETAILED TESTING
Comprehensive testing was done
in a disciplined sequence to avoid any reading omissions or entry errors
since so much data was recorded. For example, at
the pedestal, the shore power cords were disconnected and:
When the tests were complete, the recordings were doublechecked to assure that the correct boat and slip number was recorded on the data sheet. Th e dock master assisted with the validation process to avoid the misassociation of test and slip designations. This testing also reconfi rmed that the dockside electric element readings were within acceptable ranges.
Next, the shore power cords were reconnected through a wire separation adapter, the power at the pedestal was turned on, and the clamp on meter was used to on the cord to determine if there was any current leakage. A reading of 0.00 AC amps indicated no leakage.
If leakage was detected, the hot – neutral wire pair AC amperage was recorded with the clamp on meter. Then, the bond wire AC and DC amperage was read. Since the other boats on the same circuit were connected to each other through the dockside ground (green) wire and the conductivity of the salt water, the readings could have been aff ected by other boats on the same circuit and those in the vicinity of the boat undergoing the test. Therefore, if the readings of one or more boats on the same circuit or within a reasonable proximity of the boat being tested were outside of the ABYC recommended guidelines.
Some of the specific ABYC E-11 references are:
When the leakage is on the bond (ground) wire the shore power system is grounded on the boat. Any reading indicates there is a system ground on the boat.
All the boats were disconnected and then reconnected to test individually and in pairs to isolate the source of the stray current to an individual boat.
Next, the shore power cord was then disconnected, and an adapter was plugged into the shore power cord leading to the vessel. The wires were then tested for AC and DC voltage and amperage. Th en, the silver half cell was lowered about three feet into the water and connecting the meter to the adapter in the cord leading to the vessel reading the AC and DC amperage and voltage through the silver half cell and the water back to the meter the readings were recorded. Th is gave us an indication if the boat was within the ABYC recommended guidelines for galvanic corrosion for that hull type. If an isolation transformer was installed on the boat, the SYC would obtain permission from the boat owner to board the boat to test with the silver half cell on the other side of the isolation transformer through an available on board outlet. Following this process I was able to test the vessel by way of the shore power cord and back through the water for Hull Potential.
COMMUNICATION - EDUCATION – INVOLVEMENT
phase of the project was critical. To see real results, the confluence
of data, people, an education program and corrective action
encouragement was required. It was necessary for the boat owners to
accept the responsibility and take the required corrective actions
on their boats if the data indicated such a need.
Although the SYC marina is a salt water marina and
drownings/electrocutions associated with in-water currents are mainly
associated with fresh water,
there still remain life safety issues if there is current leakage on
a boat. For example, current leakage coupled with resistance generates
heat and can cause fires which could lead to the loss of life (or damage
the boat). And, there have also been documented cases of on board electrocutions
due to faulty wiring.
WHAT WE FOUND
Specific problems that I personally saw
Life Safety – current leakage:
The feedback from the boat owners has generally been favorable about how the survey has been able to help them to correct problems on their boats before a more serious situation developed. As new boats come into the marina, they are tested to assure they meet the same standards that contribute to the safe marina environment at the SYC.
KEY POINTS TO REMEMBER
The program is showing solid
progress. The Sarasota Yacht Club slip holders now have a cleaner, safer
marina where they have confidence that their
boats are less likely to suffer the effects of galvanic corrosion,
that their neighbors are less likely to adversely affect their boats,
and there is a lower probability of a marina fire or shocks caused
by AC leakage. It took a well thought out plan, hard work and a team
effort. The key elements of success were:
In addition, the SYC now has a well documented comprehensive baseline with a graphical and textual report that will aid the Club in the identification of marina or boat problems. The result is a safer marina that the members can enjoy with confidence due to the thoroughness, access and understanding of the survey.
As we move forward, SYC plans to continue to work for the members by making the SYC Marina the best and safest in the area. Maritime Surveying is proud to be part of that effort.
|Captain Stanley G. Konz has been
an ABYC member since 1991.
He is the owner of Maritime Surveying, LLC.
He can be contacted by phone at (941) 351- 6311 or via e-mail at email@example.com, or you can visit his Web site at
An ABYC Perspective…
In-water shock hazards have risen to the top of most electrical technicians’ awareness at this point. Unfortunately this awareness needs to transcend to marina operators and boaters themselves, and it is our job as marine industry professionals to make sure this happens. Th e Sarasota Yacht Club and Mr. Konz should be congratulated on taking the important step to comprehensively survey and update their dock system to ensure that the membership boats were in a safe condition. The finding that approximately one-third of the boats docked at the club had dangerous levels of AC leakage current should be a reminder to all of the insidious nature of this problem. These leakage currents can go unnoticed for years until a tragedy occurs. It’s my hope that more and more marinas and yacht clubs around North America will take this important step in the coming years. It really is a matter of life and death.