Generator + EMS + Air Conditioning = ?

[davescape]

Just purchased a 2015 Yamaha EF2000iS Inverter Generator. The wiring diagram in the back of the manual shows the neutral and ground connected and my factory installed Progressive Industries EMS concurred and gave me no error codes upon connection to the generator (EO code, 125 volts)> I believe that previous generation Yamaha Inverter Generators had a floating neutral, this no longer seems to be the case. With the EMS enabled, I get a low voltage warning and a disconnect when the Air Con is turned on (Dometic Penguin II rated at 10.5amps). I was expecting that. When I disable the EMS via the control switch, however, I get a wild loud clicking from the EMS when I turn on the Air Con. My understanding is that only the surge suppressor should still be operational with the EMS disabled. I don't think I'm getting a voltage surge however. With all the racket going on, I have no idea if the compressor is starting up on the air con. That's another issue. Any idea what's going? By the way I've tried the generator with both auto throttle mode and full throttle mode.

[steve dunham]

The generator is a seperately derived system . The neutral of the generator is not intentionally
grounded to an earth ground thusly it is hypothetically floating .The neutral is just a midpoint tap of the generator windings. Utility power is intentionally grounded to limit the voltage . The neutral is grounded at the utilities transformer and at the service entrance. In a three phase
WYE connected system the voltage from the line to the center point will vary with the load if the center point is not grounded to establish a reference point. Probably more than you needed or cared to know

[cpaharley2008]

When I operated my Penguin with the Yamaha 2000 it operated fine, as long as I turned off the EMS. Have you tried the same with hooked up to electric and EMS bypass?

[davescape]

Originally Posted by steve dunham

The generator is a seperately derived system . The neutral of the generator is not intentionally
grounded to an earth ground thusly it is hypothetically floating .

Steve, that seems to be a different definition of floating than what I've encountered to date. Usually what I hear is that if the neutral is bonded to the frame, then its not floating. This is apparently typical of most construction type generators. Inverter generators, however, typically do not connect the neutral to the frame, and are described as floating.

My generator, however, does have the neutral bonded to the frame(so says the sticker and the schematic) but also has a sticker saying its a floating system I guess that's because it has a plastic body sitting on rubber bumpers.

In any event, it does not seem to be the source of my problem since my EMS is perfectly happy with the wiring configuration. The positive and the neutral and the ground all are in perfect harmony with Progressive Industries definition of good clean well organized power. It seems I don't need any tricky grounding modifications.

[davescape]

Originally Posted by cpaharley2008

When I operated my Penguin with the Yamaha 2000 it operated fine, as long as I turned off the EMS. Have you tried the same with hooked up to electric and EMS bypass?

Jim, In bypass mode the EMS starting freaking out. CLACK!! CLACK!! CLACK!! CLACK!!..... Sounded like a cat in the rad fan.

[davescape]

Originally Posted by cpaharley2008

When I operated my Penguin with the Yamaha 2000 it operated fine?

Jim, did your air con start up fine with the generator in eco mode or did you have to run it full speed?

[Vermilye]

I wonder if they have changed bonding with the 2015 version. The on line wiring diagram still shows no bond between the ground & neutral. Since the EMS does not show the "no ground) fault, it appears that they did bond the new version, at least in Canada.

In any case, I agree that with the bypass switch on the Progressive Industries EMS activated, the relay or contractor should not be chattering. I would contact Progressive Industries for suggestions since it appears that it is still dropping out due to low voltage.

[davescape]

Originally Posted by Vermilye

I wonder if they have changed bonding with the 2015 version. The on line wiring diagram still shows no bond between the ground & neutral. Since the EMS does not show the "no ground) fault, it appears that they did bond the new version, at least in Canada.

In any case, I agree that with the bypass switch on the Progressive Industries EMS activated, the relay or contractor should not be chattering. I would contact Progressive Industries for suggestions since it appears that it is still dropping out due to low voltage.

My manual is dated 2014. Not sure if the bonding is a Canada only thing. BTW, just got back from a day trip south of the 49th Parallel: Point Roberts. Apparently the only community in the USA that has gas prices posted in Canadian dollars per litre. School children there have to pass through two borders, twice a day, in order to attend school.

[jxoco]

the schematic shows the wide blade, neutral, of the AC receptacle connected to the ground at point 14.

And I think you missed a question from someone,
" with the EMS bypassed but hooked up to shore power, does the EMS chatter?"

[Vermilye]

The schematic I found on page 42 of the owner's manual I linked above does not show the bonding at point 14. The drawing # for the one I found is 7DK10 while the # for Dave's is 7DK200. I suspect it is a Canadian difference since his diagram is also missing point 6, the generator paralleling connections. I believe the paring of generators is not allowed in Canada.

According to the manual for the EMS, you are correct that with the bypass switch on, ALL features except surge protection should be turned off: "ByPass | This switch is located on the remote display and allows the user to bypass the EMS in the event of failure, thus allowing AC power into the RV. This does not disable the surge protection portion of the EMS; however, all other features are disabled."

Again, I suggest checking with Progressive Industries if the contractor is chattering when bypassed. I have used the bypass to run my trailer during a low voltage situation (not running the AC or anything that could be damaged by low voltage), and did not have any chattering.

[davescape]

Originally Posted by jxoco

the schematic shows the wide blade, neutral, of the AC receptacle connected to the ground at point 14.

And I think you missed a question from someone,
" with the EMS bypassed but hooked up to shore power, does the EMS chatter?"

When connected to shore power in bypass mode, the EMS does not chatter.

[davescape]

I spoke with Progressive Industries this morning. They were very helpful but did suggest that in their experience, the Honda generators were a better choice (even though the EMS unit is not really designed for use with portable generators). They explained that under load, the Yamaha was putting out a modified sine wave (choppy power) and that was causing the surge protector to kick in. The surge protector is always active, even in bypass mode.

I tried out my neighbour's Honda and it worked just fine in bypass mode. The Yamaha dealer very graciously exchanged my Yamaha for a new Honda and I'm all smiles

The Honda is smoother, has cleaner power (nice sine wave ), and best of all runs my air conditioner

[jxoco]

Great to hear.
What Honda did he switch you to? a 2000 or a 3000?

I have a honda 3000, but it has the floating ground so the EMS won't use the power from it. I have bought the parts to make up a little pigtail wire for it to fool it into working but I haven't lugged the generator back out to the trailer to see how it works yet.
We have done fine without it so far, or trips have been short enough I guess.

[davescape]

Originally Posted by jxoco

Great to hear.
What Honda did he switch you to? a 2000 or a 3000?

I have a honda 3000, but it has the floating ground so the EMS won't use the power from it. I have bought the parts to make up a little pigtail wire for it to fool it into working but I haven't lugged the generator back out to the trailer to see how it works yet.
We have done fine without it so far, or trips have been short enough I guess.

I got the 2000. You should have lots of power with the 3000. The only reason we need it is to the run the AC when its really hot and we are boondocking. Our dog gets heatstroke just thinking about the sun. Hope he appreciates the effort we go to in keeping him cool. There's that and our home is susceptible to power outages. With a 2000 watt jenny we can alternate between freezer, fridge, and misc. appliances.

[jxoco]

Originally Posted by davescape

I got the 2000. You should have lots of power with the 3000.
There's that and our home is susceptible to power outages. With a 2000 watt jenny we can alternate between freezer, fridge, and misc. appliances.

Yes we have the 3000 for a cabin we have where the power can be out for a day or two whenever a wind blows hard.
I see in my dometic manual that they suggest a 3500 watt generator for my A/C.
The manual states that is draws 12.4 amps.
It is a model 600312 331c according to the sticker in the cabinet above the fridge.
Sounds like yours is better suited to running from a generator.
I'm going to have to try mine and see whats up. I always thought that I would need one of those slow-start kick start things added to it.

Good to hear your good to go. A/C can really lift your spirits on those dog days like we had this summer...

[Brian B-P]

Originally Posted by davescape

I spoke with Progressive Industries this morning. They were very helpful but did suggest that in their experience, the Honda generators were a better choice (even though the EMS unit is not really designed for use with portable generators). They explained that under load, the Yamaha was putting out a modified sine wave (choppy power) and that was causing the surge protector to kick in.:

I'm glad that this is resolved satisfactorily, but the explanation from Progressive Industries doesn't quite make sense, since the Yamaha EF2000iS was an inverter generator. These units maintain constant output power frequency despite variable engine speed by building the sine wave output with a conventional modern inverter - the inverter is the source of the output power at all times. If it is the choppy "modified sine wave" under heavy load, it should be even at very light load as well. If it is a decent sine wave at any load, it should maintain that even under heavy load. It's normally a decent sine wave because it is built in many steps per 1/60 second cycle, not just four time steps like the basic "modified sine wave" units.

This test showed that all the inverter generators tested (which includes the EF2000iS) maintained good sine wave output at both idle and full output - not perfect but far from the coarsely stepped "modified sine wave" of cheap DC-powered inverters. I was expecting to find poor voltage regulation in the Yamaha, but it never goes over the desired voltage... although it does take a long time to ramp up when the load is increased. I could see the EMS dropping out due to low voltage if active when the air conditioner is started, but presumably not if in bypass.
Product Review: A Look at Gasoline Powered Inverter Generators

[Brian B-P]

One thing I noticed in that report that I posted: "full load" in the test was 1600 watts for the EF2000iS. If pushed to the limit of what it can briefly produce, the output might not be so nice... but it's still not going to turn into something looking like the crude modified sine wave.

[davescape]

Originally Posted by Brian B-P

I'm glad that this is resolved satisfactorily, but the explanation from Progressive Industries doesn't quite make sense, since the Yamaha EF2000iS was an inverter generator. These units maintain constant output power frequency despite variable engine speed by building the sine wave output with a conventional modern inverter - the inverter is the source of the output power at all times. If it is the choppy "modified sine wave" under heavy load, it should be even at very light load as well. If it is a decent sine wave at any load, it should maintain that even under heavy load. It's normally a decent sine wave because it is built in many steps per 1/60 second cycle, not just four time steps like the basic "modified sine wave" units.

This test showed that all the inverter generators tested (which includes the EF2000iS) maintained good sine wave output at both idle and full output - not perfect but far from the coarsely stepped "modified sine wave" of cheap DC-powered inverters. I was expecting to find poor voltage regulation in the Yamaha, but it never goes over the desired voltage... although it does take a long time to ramp up when the load is increased. I could see the EMS dropping out due to low voltage if active when the air conditioner is started, but presumably not if in bypass.
Product Review: A Look at Gasoline Powered Inverter Generators

Brian, the test file that you found is what I was expecting from Yamaha, that's why I purchased it, but I didn't seem to get those results. Perhaps there is something inherent in the EMS design that's conflicting with Yamaha. I completely lack the technical skills to analyse this beyond simple observations. ...but I could put a few chords to "sine sine everywhere a sine. Blocking out the scenery breaking my mind. Do this don't do that. Can't you read the sine".