Marina Surveys are some thing we take special interest in. Marina surveys focus on the dangerous conditions that can result from electrical faults in boat and dock power systems. If current above 100 mA is leaking into the water from a boat or dock, it can kill. Surprisingly, the danger of electrocution is much greater in fresh water than salt water.
While surveying marinas, we typically find that the shore power pedestals have been wired correctly and it is more than likely the boat has on board problems. Appliances are a major concern especially ones that work intermittently. When appliances turn on by them selves and there is a short in the component there can be electricity dumping into the ground system as it should. The difference in that happening at home and that happening on board your boat are extremely two different circumstances. A boat is not wired like your home. The vessel AC ground system is connected to the BONDING SYSTEM which is connected to the DC ground system. When this occurs, the electricity travels through these connections and finds it way to the through hull fittings, engines and propeller shafts and then into the water. Extremely dangerous for anyone that swims near the boat. Can be fatal and I personally would never, ever, let my family swim in the marinas because it might not be my boat that is the problem, could be my neighbor. House boats have large house hold appliances, battery chargers, inverters etc… and are a big problem that need to be checked annually.
Here are a few of the items that we check:
- Stray current sensor all AC electrical systems, appliances, equipment.
- Check the water for electricity
- Check the dock and vessel ground system
- Check the shore power supply at the pedestal for voltage and polarity
ABYC and NFPA ANNUAL ELECTRICAL INSPECTION RECOMMENDATIONS FOR MARINAS AND YACHT CLUBS
According to ABYC and NFPA Standards and NEC Codes the marina shall establish and maintain an inspection program that will ensure that all devices that connect the slip renters vessel to the marina AC electrical system are in good and serviceable condition, and that these devices do not present the risk of fire or shock or possible ESD electric shock drowning.
This annual inspection shall apply to all boats that are connected to the marina AC electrical system, whether in open or covered slips or in a boat house. The inspection shall include the devices that connect boathouses to the docks, and the wiring of the boathouses themselves.
Standards to which all boats, boathouses and connection devices shall comply are those published by the American Boat & Yacht Council (ABYC) E-11, AC and DC Electrical Systems on Boats; National Fire Protection Association (NFPA) 70, National Electric Code; NFPA 302, Fire Protection Standard for Pleasure and Commercial Motor Craft; and NFPA 303, Fire Protection Standard for Marinas and Boatyards.
Inspection of vessels and connecting cords shall be conducted by a qualified ABYC Marine Electrician, who shall posses a membership from the ABYC (American Boat & Yacht Council) and the NFPA (National Fire Protection Agency). Inspection of boathouses shall be conducted by a Licensed Electrician, or by a member of the local Fire Department. A written report shall be completed for each vessel and boathouse inspected, and these reports shall be kept on file for documentation in the marina main office.
Each vessel shore power cord, vessel and dock power pedestal connections shall be inspected annually. This annual inspection is to document our findings and will notify the boat owner what needs to be done to secure, repair or replace there cords or connectors.
Bi-Annual inspections shall be carried out at the end of the cruising season and six months later before the cruising season, when most boats have returned to their moorings, but before they have begun to present winter heating loads to the Marina.
Any new slip renter will have their shore power cords and connections checked and then clamp metered while all AC equipment is operated by the owner. This will ensure to find any uninvited stray currents from entering the water. If there is a significant stray current found above 30 mA the owner will have to make an appointment with an marine electrician to make the repairs necessary to make the vessel safe.
A major reason for this routine inspection is to document the condition of each boats inlet receptacle, power pedestal connection and proper securing of the shore power cord itself. These connections are subject to wear-and-tear damage from the activity of connecting and disconnecting the cord, and it is also subject to damage from wet weather, and it is a major source of fire in marinas. The biggest problem is the cords end up in the water. When the cords are energized and the end is in the water the electricity is traveling directly to the nearest source of ground which is either the steel dock or the nearest vessel. Where ever the dock makes contact with the water it attracts the stray AC electrical current in the water and can hurt someone or even fatally injure if they get caught up in this path of current.
We come across boats all the time that need to be unplugged and the owners called immediately. Also if the connection between cord and the boat and the power pedestal is even slightly damaged, it will create heat that can eventually result in fire. I find plugs all the time that look good but when checked with a hand held laser thermal gun it tells a different story. We simply turn the plug or secure the cable better and the connection cools down immediately.
Thirty and fifty amp cables can be clamp metered for stray current monthly.
This can be a quick stray current finder by simply putting an inductive pick up meter around the cord. Meter readers need to learn how to use a inductive pick up clamp meter that reads milliamps and document their findings and report stray currents over 30 mA to the dock master. The dock master will notify the owner to make an appointment for the vessel to be inspected, the boat and dock ground system including the vessel’s surrounding water for electricity.
Any sign of darkening or charring at the base of the inlet prongs and heat is present shall result in the vessel being immediately disconnected from the power pedestal until the damaged receptacle, and it’s mating cord end, are repaired or replaced. Any such darkening or charring, or any sign of elevated temperatures at the receptacle or cord end, shall also signal the need for further inspection. The rear of the inlet receptacle and the wires which enter it shall be inspected, and all connections shall be proven tight. Also, the wires between the receptacle and the vessel’s master circuit breaker shall be inspected and replaced if necessary, and their connections to the circuit breakers shall be proven tight.
In addition to the annual inspections, and pursuant to the standards mentioned above, the following rules regarding the use of electrical devices shall be implemented by the marina and complied with by all vessel owners in the marina:
- All cord-to-boat connections shall be secured with properly deployed seal rings to prevent moisture from entering the connections.
- All 120 AC heat-generating devices must have three wire cords that have a round prong for the ground fault wire and shall be plugged directly into permanently installed receptacles. Extension cords shall not be used in these applications. Cords for such devices shall “not be” tightly coiled or bundled while the devices are connected.
- Domestic water heaters shall not be left energized when the vessel is unattended.
- Electric heaters that are controlled by thermostats shall be prohibited unless marine grade ignition protected in the engine room and tank spaces aboard gasoline-powered boats. In the case of engine block heaters, the thermostats that control the heaters shall be outside the engine and tank spaces.
- Engine block heaters on twin-engine boats shall be connected in such a way that only one block heater is energized at a time. This can be accomplished using a “no-freeze” thermostat in conjunction with timers.
- Unprotected light bulbs in machinery and tank spaces shall be prohibited.
- If electric heaters controlled by thermostats are used aboard vessels with propane systems, valves shall be closed on all propane storage bottles before those heaters are energized and the vessel is left unattended.
- Thermostatically-controlled electric heaters shall include a “no-freeze” setting that will turn the heater on just above freezing temperatures, and this setting shall be used when the vessel is unattended.
- Heat sources shall be secured so they or the heat they generate cannot come in contact with any flammable materials or surfaces. Space heaters are the biggest concern. Make sure a heater is not below or near curtains, bedding, clothing or other flammable materials; making sure that anything near the heater is secure and cannot tip or fall on the heater if the vessel is rocked at its moorings.