Boaters Guide to ELCI

What is ELCI?

An Equipment Leakage Circuit Interrupter is a specialized AC breaker that is designed to sense the presence of an electrical fault and shut off the flow of electricity. It works very similarly to the GFCI receptacles in your kitchen and bathroom. They differ from GFCI’s in their response time and the level of fault current required to trip the breaker. They are designed to protect the equipment as a whole from leaking current as opposed to protecting personnel from electric shock.

Why Does this Pier have ELCI when Others Don’t?

In 2011 the National Electric Code changed to require ELCI protection at the dock level. Because this only applies to new installations or major upgrades, most marinas do not have the new technology. Being a new installation, Harbor East Marina’s electrical system is ELCI protected as required by code. Additionally the American Boat and Yacht Council (ABYC) requires the boat to have ELCI protection as well, but once again, this would only apply to new installations or major electrical upgrades. While a boat side ELCI is not required for existing electrical systems, it is a recommended retrofit for all vessels.

Why is the ECLI Tripping?

In a correctly operating AC circuit, all the energy coming into the boat on the HOT wire leaves the boat on the NEUTRAL wire on its way back to its source of generation. The ELCI monitors these two lines to confirm they are in balance. When we have a ground fault onboard, some of the energy coming in on the HOT is now leaving on the safety GROUND system. The ELCI senses this and shuts down the circuit.

In a correctly wired boat, your AC GROUND and your BONDING SYSTEM are connected. AC current will take ALL available paths to ground so some of this current will leave the boat and travel through the water to return to its source. The problem can be compounded if there is a loose, corroded, or broken ground either boat-side or dock-side. Since there is no path available over the safety GROUND, all the fault current now will travel through the water.



What Does this Mean for Me?

Long story short, if the ELCI is tripping when you plug in, you have an electrical fault onboard your vessel. While it may be tempting to just move the vessel to a non ELCI protected dock, there is still a potentially deadly electrical hazard hiding onboard. Ground faults often only leak an amp or two of current and will not trip a regular breaker, however they can still provide enough current to be deadly should you come in contact with the faulty equipment, or be swimming near the boat.

How Do I Fix This?

Ground faults often require specialized equipment and knowledge to find and correct. It is recommended to hire an ABYC certified marine electrician with experience finding and correcting stray current and ground faults. However you can often perform a few trouble shooting steps to help narrow the search and safely use the boat until a full repair can be completed. See the reverse side for a basic DIY troubleshooting checklist.

Trouble Shooting Steps

  • Start by turning off all your AC breakers and unplugging the boat.
  • Plug the cord into the pedestal but leave it disconnected from the boat. Turn power on. If it trips then the problem is most likely in the cord.
  • Connect the cord to the boat but leave all onboard breakers off and turn on power at the pedestal. If ELCI trips then there is no safe way to use the boat. Call an ABYC Certified electrician asap.
  • Begin turning breakers on one by one. When you find the load that is causing the fault, leave the breaker off until a repair can be made, but you should be able to safely use the boat for now. Note: Faults are often on cycling loads so wait a few minutes between breakers to help isolate these faults.

Common Sources of Ground Faults on Boats:

  • Water heater elements
  • Household appliances. Always use marine rated appliances onboard, or have an ABYC electrician modify them for marine use.
  • Second generation galvanic isolators.

About the Author

This pamphlet was created by Bill Brandon of Tidewater Yacht Service. Bill is ABYC certified in Marine Systems and Electrical. He also holds certificates in Advanced Marine Electronics Installations and Advanced NMEA 2000 from the National Marine Electronics Association, as well as being a GARMIN® authorized installer.

Located just on the other side of Fort McHenry, Tidewater Yacht Service has been serving the boating community of Baltimore for over 30 years. Our deep draft slips and large yard allow us to haul and service boats from runabouts to yachts up to 83tons. Our ABYC certified technicians are experienced in all aspects of vessel system repair and hold factory training from:

  • Yanmar
  • Mercruiser (Master Tech on Staff)
  • Northern Lights
  • ABT-Trac
  • Glendinning
  • Vacu-flush
  • Garmin
  • And many more