Join Date: Jan 2003
Location: Maine Coast
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FYI - Suitcase Generators & ELCI's
Lately I have been researching issues with suitcase generators, such as the Honda EU inverter type and ELCI's.
Please don't take this post as me condoning the use of this type of generator on a boat, I personally don't, but it is your boat & your choice...
So what is an ELCI? An ELCI is an Equipment Leakage Circuit Interrupter for the main power feed of your boats AC system. It is your "main AC breaker" What? Huh?
Think of an ELCI as a whole boat GFCI, like you have as an outlet in your bathroom. However, instead of a 5mA trip level, the trip level is set for 30mA. ELCI's are in a class of device called Residual Current Devices (RCD's). These devices respond to electrical leakage outside the intended path.
The intended path for a 30A shore power feed is BLACK/HOT & WHITE/NEUTRAL. These two wires are the ONLY place any current should be flowing in a properly operating system. If measured under load the BLACK & WHITE wires need to be in 100% agreement. If the current on these wires is not the same on both, you have a "leak". When the leak gets to 30mA the ELCI will trip to keep swimmers, workers and vessel occupants safe. In your bathroom or kitchen at home when the "leak" gets to 5mA the GFCI trips. The 30mA level is/was intended to prevent "nuisance trips" yet still keep humans safe.
Marina's in the US have HORRIBLE issues with voltage leaks. I measured one marina just yesterday and approx 30%, of the in-water stored/live aboard vessels, had leaks larger than the 30mA. These leaks would trip an ELCI, as they should.. 30mA is a leak of just 0.03A of AC current.
Electric Shock Drownings (ESD's) can be caused by just 12 - 20mA of leakage current. While the ELCI trips at 30mA the trip time is short enough to avoid an ESD. ELCI's are about human safety first and they are now part of the ABYC standards. RCD's have been part of the European standards for quite a while and we lagged behind them on this.
So what does an ELCI have to do with my Honda, or other brand, inverter generator?
I have had two customers, one a consult customer and one a direct customer, who have had issues with the Honda generators tripping the newly installed ELCI.
The Honda and some Yamaha suitcase generators use a "open ground" at the generator end. Honda ADAMANTLY advises against bonding the WHITE/NEUTRAL to the GREEN/EARTH at the generator end. They will not even discuss it any further than DO NOT DO THIS. I have reached as high up as I can go in their engineering department to get an answer as to "why" but they will NOT give you one. The Honda "party line" is DO NOT bond GREEN to WHITE at the generator. Could it work? Some on the net claim it can, but it is your generator and your risk..
An open ground at the AC source end (Honda generator) does not meet the safety trip parameters for a marine ELCI and also does not meet OSHA standards either. Inverters and permanently installed "marine" gen sets bond GREEN to WHITE at the source. It should be noted that other than at a source (marine rated inverter, marine gen set or land) GREEN & WHITE are NEVER tied together on the vessel.
So why does the ELCI trip when connected to one of these generators?
The ELCI is intended for the ultimate in human safety but perhaps not convenience when that convenience does not meet applicable safety standards..
I called Carling Technologies last month to find out why this was happening. Carling makes most of the ELCI's sold by the marine electrical suppliers. Essentially the ELCI looks for an EARTH/NEUTRAL bond at the source end. With a land source the NEUTRAL and GREEN are tied together (but NEVER ON THE BOAT). This is what the ELCI wants to see at the "source" is a NEUTRAL/GREEN bond. The Honda EU1000, EU2000 etc. do not have this GREEN/WHITE bond at the generator end. On their larger non-inverter generators they do bond GREEN & WHITE as these are often used on job sites overseen by OSHA..
The inverter generators don't use a NEUTRAL/GREEN bond at the source and thus an ELCI will trip.
So, if your boat has an ELCI, and you want to use a Honda suitcase generator, you will need to call your marine electrician or install a marine gen set..
-Maine Sail / CS-36T
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