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Author Topic: Oddities with a Honda genny - reversed H-N  (Read 4463 times)

frank kayser

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Oddities with a Honda genny - reversed H-N
« on: March 09, 2018, 10:41:59 am »

Well, the wind blew the power out last week, and my trusty Honda EU-1000 came out for lights and the fridge.


Getting power into the house used to mean a power cord through the garage door and then through the kitchen door to the garage.  Of course that left a gap.


Last year I created a plug-in pass through to eliminate the problem.


OK the stage is set.


Ran my stage cords all through the house, fired up the genny, and went to test just for giggles. My stage power cords were showing red - some type of fault, but the GFCI seemed happy enough.


Plugging in my Extech tester, it said the hot neutral was reversed!  Damn, I thought, I must have screwed up the pass through and reversed the black and white.  No, I did not cross check it with a multimeter or a NCVT.


On my way out the door, I remembered I had a factory built extension cord plugged in for my network.  I plugged in the Extech there, and it also showed reversed H-N.  Well, at least it wasn't my work.


But that meant the genny was sending reversed H-N out its outlets.


I know Honda does not bond Neutral to Ground at the genny.


I also remember reading somewhere the little Honda EU-1000 acted differently than its bigger brother.  I left it as is, and weathered the power outage.  Now I want to know what it is that is going on.


Any help?
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TJ (Tom) Cornish

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Re: Oddities with a Honda genny - reversed H-N
« Reply #1 on: March 09, 2018, 10:49:22 am »

Well, the wind blew the power out last week, and my trusty Honda EU-1000 came out for lights and the fridge.


Getting power into the house used to mean a power cord through the garage door and then through the kitchen door to the garage.  Of course that left a gap.


Last year I created a plug-in pass through to eliminate the problem.


OK the stage is set.


Ran my stage cords all through the house, fired up the genny, and went to test just for giggles. My stage power cords were showing red - some type of fault, but the GFCI seemed happy enough.


Plugging in my Extech tester, it said the hot neutral was reversed!  Damn, I thought, I must have screwed up the pass through and reversed the black and white.  No, I did not cross check it with a multimeter or a NCVT.


On my way out the door, I remembered I had a factory built extension cord plugged in for my network.  I plugged in the Extech there, and it also showed reversed H-N.  Well, at least it wasn't my work.


But that meant the genny was sending reversed H-N out its outlets.


I know Honda does not bond Neutral to Ground at the genny.


I also remember reading somewhere the little Honda EU-1000 acted differently than its bigger brother.  I left it as is, and weathered the power outage.  Now I want to know what it is that is going on.


Any help?
IIRC, the single-circuit Honda EUs actually are a balanced power arrangement - 60 volts from hot to the floating ground, 60 volts from neutral.  This may confuse your meter.
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Debbie Dunkley

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Re: Oddities with a Honda genny - reversed H-N
« Reply #2 on: March 09, 2018, 02:48:01 pm »

Well, the wind blew the power out last week, and my trusty Honda EU-1000 came out for lights and the fridge.


Getting power into the house used to mean a power cord through the garage door and then through the kitchen door to the garage.  Of course that left a gap.


Last year I created a plug-in pass through to eliminate the problem.


OK the stage is set.


Ran my stage cords all through the house, fired up the genny, and went to test just for giggles. My stage power cords were showing red - some type of fault, but the GFCI seemed happy enough.


Plugging in my Extech tester, it said the hot neutral was reversed!  Damn, I thought, I must have screwed up the pass through and reversed the black and white.  No, I did not cross check it with a multimeter or a NCVT.


On my way out the door, I remembered I had a factory built extension cord plugged in for my network.  I plugged in the Extech there, and it also showed reversed H-N.  Well, at least it wasn't my work.


But that meant the genny was sending reversed H-N out its outlets.


I know Honda does not bond Neutral to Ground at the genny.


I also remember reading somewhere the little Honda EU-1000 acted differently than its bigger brother.  I left it as is, and weathered the power outage.  Now I want to know what it is that is going on.


Any help?

Not the answer to your question Frank but I run my gennys in the outside screened porch and then have the cables come into the house through a sash window. I cut a piece of dense rubber foam to run along the length of the window ledge and cut a small hole in it for the cable to pass through. I pull the window down to compress the foam and the seal is perfect.
Of course it isn't a good security measure but I only use this system when I am home to monitor the generators.
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frank kayser

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Re: Oddities with a Honda genny - reversed H-N
« Reply #3 on: March 09, 2018, 04:40:30 pm »

IIRC, the single-circuit Honda EUs actually are a balanced power arrangement - 60 volts from hot to the floating ground, 60 volts from neutral.  This may confuse your meter.


Thanks, TJ.  I believe that is what I read some time ago here.  I'll have to throw a meter on the genny to verify.  Another reason why a multimeter is our best friend. 
A backup question, if you please - the neutral-ground bonding plug that Mike Sokol has talked about here and on the RV forums does not seem appropriate on this particular genny.  Does that sound right?


Not the answer to your question Frank but I run my gennys in the outside screened porch and then have the cables come into the house through a sash window. I cut a piece of dense rubber foam to run along the length of the window ledge and cut a small hole in it for the cable to pass through. I pull the window down to compress the foam and the seal is perfect.
Of course it isn't a good security measure but I only use this system when I am home to monitor the generators.

Thanks, Debbie. Good plan. That assumes that I am as prepared as you! (or as smart!) Proof in the pudding: years ago, they were relining the water main on my street.  Normally a hose is run from the temporary water main to an outside faucet to temporarily supply the house.  I have a one-way valve on the feeder line blocking incoming water, so that plan to feed the house had to be adjusted.  They fed the hose through the front window to the water meter.  I don't remember sealing the window with foam strips or securing the window for the couple weeks it took from beginning to end.  I must have put something on the window to keep the bugs out but... Cardboard, maybe? Certainly not a good sealing foam!
There will be other times and places where I will use your foam trick... Thanks Debbie! 


So, maybe an info trade?
As for security - a 2x2 or something similar fit snugly between the top of the bottom sash and the upper window frame will keep the window from going up.  Gaff tape it in place so anyone trying to shake it out of place to gain entry will have to spend too much time getting around your "security package" and will look elsewhere. Two sticks may be better than one...


Of course, if the top sash is movable a slight adjustment needs to be devised. Maybe a small bracket screwed to the top sash where the stick could secure both windows.



Sometimes indirect answers give as much utility as an answer that is narrowly focused on the problem. 


frank
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Mike Sokol

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Re: Oddities with a Honda genny - reversed H-N
« Reply #4 on: March 09, 2018, 05:40:54 pm »

Thanks, TJ.  I believe that is what I read some time ago here.  I'll have to throw a meter on the genny to verify.  Another reason why a multimeter is our best friend. 
A backup question, if you please - the neutral-ground bonding plug that Mike Sokol has talked about here and on the RV forums does not seem appropriate on this particular genny.  Does that sound right?

If it indeed has 60/60-volt balanced power, then you'll get really strange readings with any 3-light outlet tester, and a G-N shorting plug will just short the generator output. I've seen this 60/60 split power on some cheap Chinese inverters, but never on a Honda generator. Still, anything's possible with generator manufacturers.
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Stephen Swaffer

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Re: Oddities with a Honda genny - reversed H-N
« Reply #5 on: March 09, 2018, 06:44:53 pm »

Here's the thing-on ANY electrical supply supplying 120V power the thing that makes a neutral a neutral is a "Ground-neutral" bond.  The NEC actually uses the term "grounded conductor" not neutral.  On a 240 volt "split" phase service typical of resi and commercial single phase power, it is critical that the "grounded conductor" be connected to the center tap of the transformer to get the correct voltages.  If you have only a 120 volt supply, then nothing is neutral until a bond makes it a neutral.

Honestly, if there is no bonding to ground, I don't see how it can be "balanced" power as there is no reference point.  It would be interesting to check the voltage to ground from each side of the receptacle and monitor it as loads change.  If is more or less a "rock steady"  60 VAC, then I would consider it balanced.  My guess is that you will see it float around.
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Steve Swaffer

Jonathan Johnson

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Re: Oddities with a Honda genny - reversed H-N
« Reply #6 on: March 10, 2018, 01:35:33 am »

Honestly, if there is no bonding to ground, I don't see how it can be "balanced" power as there is no reference point.

The same way your microphone is balanced without a reference point.

If your power supply is connected to ground, either  center tapped or side tapped, it is by definition unbalanced. For center tapped, you have two unbalanced power supplies that happen to be opposite voltage relative to the grounded tap.
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TJ (Tom) Cornish

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Re: Oddities with a Honda genny - reversed H-N
« Reply #7 on: March 10, 2018, 07:26:27 am »

I did a fair amount of research on the EUs 6 or 7 years ago, but itís been quite a while, and I donít regularly use the single-circuit ones, so I could be all wet, but here is what I remember:

The neutral is unbounded to ground.  In a small system, there are pros and cons to this - the major con is youíll never trip the circuit breaker if you have a hot->ground fault.  The upside is that if you only have a single fault - hot->ground for example, as you have no hard earth reference, effectively the hot wire becomes the neutral wire and the neutral wire becomes the hot wire, so your likelihood of getting a significant shock isnít terribly high.

Note that the above falls apart if the generator has more than one circuit like on the UE6500/7000.  In larger systems, having a bonded neutral is essential (unless youíre in Europe :) ) since there are more fault current paths.  Interestingly, the EU6500/7000 arenít bonded either.  The reason for this is their frequent use as home backup generators, where creating a second ground->neutral bond (the first is in your home breaker panel) causes a safety issue.  For portable use, the larger EUs should absolutely be bonded - ideally inside the generator, which Honda doesnít provide an easy means of doing, or on the generator - a dummy Edison plug with a jumper between neutral and ground.

Back to the EU1000/2000 - I donít remember if the EU actually derives its power via two 60 volt windings/inverter channels relative to the chassis or if the earth ground is impedance balanced by a couple capacitors, but in either case, this will screw up the various all-in-one outlet testers.  A real multi-meter will reveal the truth.  Please test and report back.
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TJ (Tom) Cornish

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Re: Oddities with a Honda genny - reversed H-N
« Reply #8 on: March 10, 2018, 07:30:46 am »

Honestly, if there is no bonding to ground, I don't see how it can be "balanced" power as there is no reference point.  It would be interesting to check the voltage to ground from each side of the receptacle and monitor it as loads change.  If is more or less a "rock steady"  60 VAC, then I would consider it balanced.  My guess is that you will see it float around.
Capacitor coupling will sink enough current to confuse a typical high-impedance meter (and shock you for that matter - lots of cheap ungrounded wall-warts put 60v on the negative terminal which is enough to feel if your other hand is on something with a good ground path).  A meter with a low-impedance measurement mode will provide a better view of reality.
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Frank DeWitt

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Re: Oddities with a Honda genny - reversed H-N
« Reply #9 on: March 10, 2018, 09:29:19 am »

Looking at the internal wiring diagram, there is no connection between the inverter and ground.  The AC output is floating.  Also worth noting  The synchronizing jacks and the kit for them is not polarized.  this means that when two generators are synchronized the "neutral" (longer slot on the outlet)  can be at the same potential (Hard wired) to the "hot" or shorter slot on the outlet of the second generator.

The outlets of two generators can be reversed

So if you bonded the "neutral on one generator to ground. you have a 50% chance that you have bonded the "hot" of the second generator to ground.

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