This page summarizes the ELCI issues we have been having since the boat was new. The first incident was on the dock in Blaine during commissioning.

Last updated: 17-Apr-2023

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Problem Summary: The ELCI breaker trips when the boat is unoccupied, at dock, with most systems off. Happens on both forward and aft breakers in different marinas with different shore power cables on both 30A and 50A power. This happens every few weeks to every few months. It seems to happen far more frequently when the outdoor temp gets very cold or very warm. This is an intermittent failure without a repro case. 

Current state: We leave the boat with almost everything turned off. The only things running with any kind of AC draw are the House Bank charger and the Fridge. Inverter is off, so AC loads are directly on shore power. 

Troubleshooting to date: 

  • There is a 24V charger running on AC that was cycling the fan on at random times (not hot, charger not running). Sent back to ProMariner who tested it and sent it back as “OK”. Now we just leave the 24V charger off when we leave the boat. 
  • The fridge died and we replaced the control board and main fan. 
  • Worked with ABYC Electrician (Dan Heyl at Emerald Marine) to tighten and test everything on the AC bus. Confirmed no cross-wiring between the neutral and ground busbars. 
  • Replaced the aft ELCI breaker

Ruled out:

  • Bad Breaker. The new breaker tripped a month after installing it. 
  • Galvanic Isolators – really anything else associated with one or the other shore power inlets. The issue happens on both so the problem must be something associated with both. 
  • 24V charger – we just leave this turned off
  • Random AC devices. We remove/unplug almost all devices on the boat when we’re gone. Exception is the WiFi, fridge, and water maker control panel.  
  • Incorrect wiring – confirmed with electrician there is no cross-wiring and tightened all lugs on the AC busbars. 
  • The Water Maker panel – this is very low draw and the trip happens whether or not it is on. 
  • The refrigerator – turned the fridge off at the main panel in early March, ‘23 and the ELCI breaker tripped on 2-Apr-2023. Low 30s at night, again. So, the breaker trips when the fridge is off.


  • There is some corrosion on the ground bus in the lazerette bilge. I cleaned this up and confirmed no resistance on the main copper strap. Also, this corrosion was caused by the leak I caused after damaging the stern thruster. The ELCI trips have been happening since the boat was new, before this corrosion.

Next Steps

More troubleshooting. Some of these are “change something and see what happens”. A successful lead is we don’t have a trip for three months with 2-3 days of very high or very low temps. 

  • Confirm Shore Power Cable – this issue happens with both our 30A and 50A cables. The 30A cable is a custom cable with the poles bridged, which could cause some AC leakage. However, the problem also happens with our standard 50A cable. It’s possible BOTH cables are bad. Try a different 50A cable.
  • Problem is in main 12V battery charger/inverter. Something inside the inverter is sensitive to heat/cold or humidity (the unit is in the Laz). Unclear on how to test this. Open case and look for condensation?
  • Problem is somewhere in the wiring. Use a Megger to test every circuit for leaks. Keep in mind that the neutral and ground are shared, so problems could be caused by leakage on another circuit. 

Crazy out of box stuff: 

  • If it’s the Inverter Charger – either repair or replace it with a Victron. 
  • If we rule out the inverter/charger, use a meghometer to test every circuit
  • If that doesn’t find it, install a boat-wide isolation transformer. (*OR* For the cost of an isolation transformer I can change out the inverter and switch the house bank to lithium).