Honda inverter/generator neutral voltage maybe?

[ritelec]

Hello.

27 yrs in the house... lost power "Once" for two or three hrs last year.

Neighboring towns lost power for a week or two from hurricane couple years back.

If I were to lose power,

My concern is heat and "mainly" heat trace tape for a flat roof that has plagued me for years

I went for the Honda eu2000i for a small backup for house and maybe jobsite for service changes etc...

My main panel is 200 amp (main breaker panel) off an outside main breaker disconnect.

The eu2000i is 120v only.

I would like to back feed the panel, leave all 240v circs off. Keep a couple low amp loads like gas boiler, heat tape, fish tank on and and cycle through frig. freezer. and other loads as needed.

Was no biggy in my head, but I read something (that I can't locate now) that someone wrote in a review that the electronics of something he was trying to run wouldn't work because there was 60v on the neutral.
(I'm assuming that was neutral to ground, but after locating a schematic I see that neutral and ground are common so I can't see it or know what he was talking about)

page 56

http://cdn.powerequipment.honda.com/pe/pdf/manuals/31Z07610.pdf

Does anyone see the potential for voltage on the neutral?

On the unit I got, "if" there is voltage and also if I can't separate the neutral/ground bond..

would it be better to pull the neutral/ground lines off the bars in the panel?

Thank you




edit . just thinking if there is voltage (or even not). should I remove the house lines from neutral and ground, and bond neutral to ground at the eu2000i (via jumping a male plug with a neutral to ground jumper and inserting it in one of the eu2000's duplex receptacles)?

 

[GoldDigger]

I think you are referring to some low cost Modified Square Wave inverters which generate an AC output in which the two output terminals alternate between +60 and -60 with respect to the battery ground and their case ground. The practical result is that you must not bond either AC line to ground.
A Pure Sine Wave inverter or a higher quality MSW inverter (including the inverter section of an inverter type generator) will not do this.
Not a concern with the Honda.
But you may have a separate issue for generators which bond neutral to ground and include an output GFCI.
This requires you to treat it as an SDS and remove the ground neutral bond at your transfer switch.

 

[hurk27]

A voltage between the neutral and ground is always possible when you have a floating grounded system, also since there is no bond between the neutral and EGC you have no ground fault path, is this a problem not with most appliances because the load is between the hot and neutral, but with heat tape a fault in the tape can go un-notice since there is no fault return path for the heat tape shield that 426.26 requires on snow melt tape, also 426.27 requires that a GF device (30-50ma not a GFCI) device to be installed so if a fault was to happen because the tape is surrounded by the braided shield it would trip the GF device without causing a fire, so I would say that a neutral to ground bond would have to be made because with this generator wired as is would not allow the GFPD to operate.

The other problem is the capacity of this generator is not what you think, it is rated 1600 watts continuous and 2000 watts for up to 30mins (see page 61 in the PDF). which is not a whole lot, think of it this way, a 15 amp breaker can supply 1800 watts @120 volts and never trip, this generator is less then that, depending upon the total wattage of the heat tape it might not even be able to supply it continuous if over 30mins, I would not even think of back feeding my panel with this small of a generator, second the only safe way to feed the panel is through a transfer switch, I do have 6 small 30 amp rated transfer switch's on my own house that don't transfer the whole panel but just certain circuits to inverters that are powered by a backup 12 volt battery bank of 20 semi truck batteries with stud mount cable connections, these are charged by a float type charger system that keeps the batteries at float voltage then they shut off without boiling the water out of the batteries, two of the inverters are 1800 watt and 4 are 1000 watt, none of them are loaded to the max so I can get about 8 hours of back up before I have to hook up a couple cars to charge them back up, kind of a hillbilly UPS system but it works, most of my loads are very light with the furnace and fridge being the heaviest, all my lighting is CFL.

You need to take an amperage reading on the heat tapes then multiply this by the voltage they are running on to see what the wattage is, 1600 watts is only 13.1/3 amps so if they are more then this you will not be able to use the generator to supply it, even if they are only 10 amps you would only have 3.1/3 amps to supply anything else you would want to, my best advice is to get a bigger generator or set your loads up so you can just plug them in, feeding the whole panel leaves it to easy to overload this small generator and from experience these inverter generators don't take much to burn up the inverter, sure they have overload protection but trust me, if you leave it supplying a load at or just above 2000 watts its overloads will never trip, they are only designed to trip on a fault or a larger overload, remember they are design to feed a 2kw load for 30 Min's. but it will damage the inverter if you run that high of a load over 30 Min's.

These inverter generators have the same type of overload protection that some inverters that you hook to your car battery does, its called electronic and it soft offs but if you are right at the 200 watt mark it will not shut the inverter down and over heating of the inverters output transistors and heat sink and can damage them, this is why if you over load an inverter you don't want to fire it right back up without giving it a chance to cool down as the heat sink can hold the heat for a while.

We had one that one of our workers tried to use a large hammer drill on it, and it kept tripping on overload, he would shut the generator down and restart it to try to get a little further with the 3.5" hole saw, after about 5 times the generator stopped putting out any voltage as the inverter was fried, our boss was very upset as he wasn't even supposed to have taken this generator as it was the one he used for his camp site, which is all about they are good for as they are very quite.

One nice feature is you can gang them by using the paralleling cable to parallel two together to double the output to get 3.2kw continuous output.

 

[hurk27]

The schematic if the Honda eu2000i found on page 56 in the PDF does not show any neutral to ground bond, also since the EGC is floating the capacitance coupling between any hot and the EGC or and capacitors or MOV's and the ground in any surge strips can cause a voltage to read between the neutral and ground, how much depends on the amount of coupling there is, a MOV between hot and ground and neutral and ground will split the 120 volts down the middle and give you 60 volts from neutral and ground which I think is what this person was seeing because of the mentioning of electronics a surge suppressor might have been used, this voltage does not have any current backing it up, any small load would have most likely made it disappear.

I have been running many inverter systems in my work vans for years, and have never had any problems with bonding the neutral to the chassis ground or the van ground which doesn't mean like you said some may, some of my first inverters were MSW and very dirty output, which after burning up a couple dewalt chargers and a few other electronic items I started only using pure sine wave inverters or running then through a 1:1 transformer to fly wheel it to a pure sine wave, most PSW inverters either uses 7 pulse, pulse width modulation or a flywheel transformer to fly wheel the output into a full sine or both, like I said I have used a 1:1 120 volt transformer to get a cleaner sine wave from a MSW inverter for electronics but it does eat up the output capacity of the inverter and the RMS voltage comes out lower, I have adjusted the voltage on some to bring up the RMS voltage level but you can only do this if you run it through a transformer other wise the peek to peek voltage will be way to high, older Triplet PSW used the transformer driven by output transistors that provided a very clean and accurate sine output, on a scope you could not tell the output from the utility's except the noise you can get from the utility would not be on the inverters output, but these were very expensive inverters, I still have a 3600 watt one that was in my 2007 van which was totaled, I was told that new this inverter was over $7k it was in an expensive RV that was wrecked beyond repair (totaled) and the junk yard had no clue and let me have it for $25, it had a 25 amp float charger and 30 amp rated automatic transfer switch along with a small RV breaker panel, isolation diode system and resistor bank to limit the charging current from the alternator to 30 amps.

Another problem I found with MSW inverters is universal motors (DC) found on hand saws and drills would run much slower since the MSW inverters would not provide a RMS voltage as high as the utility's, regular squirrel cage motors would run at the right speed but would pull more current and or stall easier and run warmer.

 

[ritelec]

Thank you for the info.

I agree, it's not much of a generator for power out, and at a fraction of the price I could have gotten a real generator (6 kw non honda 120/240)..

I figure load (and may be off) but,

Heat Tape- I believe it's this.. http://www.grainger.com/product/RAYCHEM-Self-Regulating-Heat-Cable-4E516
(put in 14 years ago, which I'm also concerned how long does it last) @ no more than 30' @ .06amps per foot = 1.8 amps

Boiler - gas fired, 5 lv zones, damper motor, circulator ??? @ 240va = 2amps

fish tank @ 16w = .2 amps

(maybe lv alarm system panel.. and 120v smoke alarms. how much amperage would they be? smokes are 9 firex heads)

Then alternate between the frig, freezer, laundry, micro, etc... as needed. (one and only one at a time depending on what's needed)



I put the heat tape on a dead face gfci all those years ago.. should and will replace.


Shedding/alternating loads, will be tight but I think I can work with it.... my big concern was/is the neutral being hot and back feeding into the grid.

....."feeding the whole panel leaves it to easy to overload this small generator and from experience these inverter generators don't take much to burn up the inverter, sure they have overload protection but trust me, if you leave it supplying a load at or just above 2000 watts its overloads will never trip, they are only designed to trip on a fault or a larger overload, remember they are design to feed a 2kw load for 30 Min's. but it will damage the inverter if you run that high of a load over 30 Min's"......

yes.. scary

...."I think you are referring to some low cost Modified Square Wave inverters which generate an AC output in which the two output terminals alternate between +60 and -60".....

It was in a review where 99.9% of people were glorifying the honda 2000 but one guy had an issue with it.. which the issue of voltage on neutral caught my eye.

hopefully it was/is

..."the EGC is floating the capacitance coupling between any hot and the EGC or and capacitors or MOV's and the ground in any surge strips can cause a voltage to read between the neutral and ground, how much depends on the amount of coupling there is, a MOV between hot and ground and neutral and ground will split the 120 volts down the middle and give you 60 volts from neutral and ground which I think is what this person was seeing because of the mentioning of electronics a surge suppressor might have been used, this voltage does not have any current backing it up, any small load would have most likely made it disappear"...



"One nice feature is you can gang them by using the paralleling cable to parallel two together to double the output to get 3.2kw continuous output"
YES