Honda generator and reverse polarity

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ChrisCall

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Mar 27, 2016
89
Catalina 30 Hingham
I had a micro air soft start installed on my boat so we could run the AC on our hunter 36 while we were on a mooring . ( not going to run it at night just for an hour or so during the day to take some of the heat and humidity out .my girlfriend dosen't do well with humidty and last when we went away it was 90% or better the whole trip and she was miserable. Also we carbon monoxide detectors. )
When I plugged it in the reverse polarity light came on. ( no revere polarity light when I plug it into dock poll.) So I unplugged and decided to do
some research before I went further.
I have read it's normal for a honda generator to do the just run it.? Any help would be appreciated we are heading out this weekend and it's going to be in high 90s
 
jviss

jviss

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Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
Interesting. Is the Honda ground connected to the boat ground? I would assume so, via the plug. Interested to hear what this is all about.
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,674
Canadian Sailcraft 36T Casco Bay, ME
The Honda, Yamaha etc. inverter suitcase generators use a "floating neutral" at the generator end. This means that the neutral and ground are not "bonded" at the "source of power" as required by marine electrical safety standards. In the marine world, when plugged into shore power, the neutral and ground are bonded together at the shore source. When running an inverter, for example, the installed system must create a neutral to ground bond when the inverter is operating as the source of power, and the same goes for a marine genset. However, when there is no other "source of power" operational (installed generator, Inverter or portable generator) the vessel must not have any on-board neutral to ground bonds.

Unfortunately Honda advises against bonding the WHITE/NEUTRAL to the GREEN/EARTH at the generator end. This is likely because the unit is actually putting out approx 62V on neutral and 62V (what you will measure with a DVM). It's just the way they work. Honda engineering will not even discuss it other than than DO NOT BOND GEN NEUTRAL TO GEN GROUND.

In the past 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 an answer. The issue of floating neutral generators has wreaked havoc on numerous vessels where an ELCI main breaker has been installed to meet marine safety standards and the portable generator causes nuisance trips. The Honda party line is do not bond GREEN to WHITE at the generator. They also say this will void warranty.

Can it work? Many owners go ahead and do it, but it is your generator and your risk. The bottom line is these are not "marine generators" and as such do not comply with marine wiring standards. It is a "use it on your own" situation..
 
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dLj

dLj

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Mar 23, 2017
3,425
Belliure 41 Sailing back to the Chesapeake
It's unclear to me, did you plug directly into the Honda generator and get the reverse polarity indication?

dj
 
C

ChrisCall

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Mar 27, 2016
89
Catalina 30 Hingham
Yes I went from my shore power conection to a pigtail to genorator. Also were you are talking about bonding the generator. Micro air sells a generator bond plug would that be a work around?
 
C

ChrisCall

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Mar 27, 2016
89
Catalina 30 Hingham
And when you say many owners do it . Do mean they just ignore the reverse polarity light?
 
Nodak7

Nodak7

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Sep 28, 2008
1,249
Hunter 41DS Punta Gorda, FL
We use Honda Generators (Both the Gen and the Companion in parallel) and have never experienced this "reverse polarity" issue. Are we lucky or is there something different about our set-up?
 
C

ChrisCall

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Mar 27, 2016
89
Catalina 30 Hingham
Not sure my boat is a 2004 hunter 36 the setup is AC is Wabasto 16000btu and it has it's own shore power conection and AC breaker with micro air easy start.
 
C

ChrisCall

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Mar 27, 2016
89
Catalina 30 Hingham
So when you say bond the green to white do you mean in the generator or the pigtail cord. Or would the generator bonding plug that micro air sells do the trick?
 
SycloneDriver

SycloneDriver

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Jul 23, 2009
857
Beneteau 31 Oceanis Grand Lake, Oklahoma
A bonding plug should be easy to make. I think the instruction are on you-tube.
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,674
Canadian Sailcraft 36T Casco Bay, ME
A bonding plug is just a NEMA 5-15P (extension cord replacement male end) with a jumper between the neutral and the green. They are used in the RV world, due to on-board surge / line protectors, that simply will not work with a floating neutral. You just plug it into one of the unused outlets and you now have a neutral/ground bond for the generator.

Again, Honda does not support this and it will void warranty, these generators do not meet marine safety standards, but it is done by owners willing to accept the risk..
 
Johnb

Johnb

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Jan 22, 2008
1,421
Hunter 37-cutter Richmond CA
Maine Sail said:
This is likely because the unit is actually putting out approx 62V on neutral and 62V (what you will measure with a DVM). It's just the way they work.
Click to expand
Is there something missing from that sentence? Should I assume that the output is 120 volt split phase?
 
walt

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
More likely reading 1/2 voltage is due to the floating ground having equal parasitic capacitive coupling to hot and neutral. The impedance of the capacatance at 60hz is much lower than the impedance of the DVM used to measure so you see half the voltage on the floating node.

In this case it would seem like a bad idea to bond the earth ground to the neutral if there is really was 62V across the line.. but more likely you are just measuring a parasitic artifact of the green line floating. If you want to make sure, turn the generator off and measure the resistance from green to white and green to black. If the resistance is very high (like mega ohm range or more), its a floating ground

Note.. I have not actually tried this to verify.. maybe someone could.
 
jviss

jviss

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Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
walt said:
More likely reading 1/2 voltage is due to the floating ground having equal parasitic capacitive coupling to hot and neutral. The impedance of the capacatance at 60hz is much lower than the impedance of the DVM used to measure so you see half the voltage on the floating node.

In this case it would seem like a bad idea to bond the earth ground to the neutral if there is really was 62V across the line.. but more likely you are just measuring a parasitic artifact of the green line floating. If you want to make sure, turn the generator off and measure the resistance from green to white and green to black. If the resistance is very high (like mega ohm range or more), its a floating ground

Note.. I have not actually tried this to verify.. maybe someone could.
Click to expand
Are you an electrical engineer? Most of this sounds like gibberish to me.
 
walt

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
jviss said:
Are you an electrical engineer? Most of this sounds like gibberish to me.
Click to expand
Yes.. MSEE and retired analog engineer. Worked on AC systems in factories in China for consumer electronics among a lot of other things. I think you are an EE also?
 
jviss

jviss

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Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
walt said:
Yes.. MSEE and retired analog engineer. Worked on AC systems in factories in China for consumer electronics among a lot of other things. I think you are an EE also?
Click to expand
Yes, I am.

Let me elaborate on my criticism.

1. Of course it's floating! There's no ground reference on the generator, it's only putting out 120V between hot and neutral;
2. the "1/2 the voltage across the line" is just that the generator is floating, it will be zero, with no current flowing, if you tie the green and black together;
3. you can't accurately measure high resistances with a DVM, you need something like what we called "a maga," a megaOhmeter, the uses very high voltages.
 
walt

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
2. the "1/2 the voltage across the line" is just that the generator is floating, it will be zero, with no current flowing, if you tie the green and black together;
Click to expand
I dont think we are arguing about anything. My response was to the "split phase" comment which would have implied that you dont want to bond ground and neutral. Ie, if you are measuring 62 volts between two wires, you should be very cautious about shorting them (like the plug that connects green and white that MainSail showed).

DVM is just fine in this case for measuring impedance to make sure the ground is floating. If you measure in the mega ohm range, that is "close enough" to call floating as any parasitic currents from connecting green and white would be very small.

I dont really want to ague about this.. but if you do, please add some numbers to the conversation.
 
jviss

jviss

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Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
Yes, an argument would be pointless, as it doesn't change how the OP will use this. But you should know that you can't measure impedance with a DVM. :)
 
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