Generator on Propane/NG Issue

northerner

Re: Generator on Propane/NG Issue

Blackcherry04 wrote: »

I agree with North Guy, it's just a number. Mine on the Mate dance all over the place and they change often, what you see one minute may not what you see in 10 Minutes. Part of it may be the sampling and part is that the charger output / input seems to be a dampened number.

Ok, so nothing to be concerned about then.

Blackcherry04

Re: Generator on Propane/NG Issue

northerner wrote: »

Ok, so nothing to be concerned about then.

Thats what I would say, On a Xanterx SCP you can see more like real time numbers of the charger output and load consumption, they have 20 amp ( charger ) swings every second as the controller keeps the limits in sync with each other, on the Outback it's doing it, but you just don't see it on the mate.

northerner

Re: Generator on Propane/NG Issue

Blackcherry04 wrote: »

Thats what I would say, On a Xanterx SCP you can see more like real time numbers of the charger output and load consumption, they have 20 amp ( charger ) swings every second as the controller keeps the limits in sync with each other, on the Outback it's doing it, but you just don't see it on the mate.

Ok, thanks for that!

vtmaps

Re: Generator on Propane/NG Issue

northerner wrote: »

So when I'm reading 1400 watts in from the generator and 1000 watts of charging + 400 watts load when the actual load is around 100 (+) watts, I would actually be charging at 1300 (-) watts rather than the indicated 1000 watts? I should check this out with a meter.

The charger is less efficient than the inverter... you may be burning up a couple of hundred watts in the charger. Perhaps that is part of the 'load'.

--vtMaps

northerner

Re: Generator on Propane/NG Issue

Another observation. I ran the generator on gasoline this morning, which allows the generator to put out a full 1600 watts continuous. The mate shows the proper load when the generator is able to meet the demand the Outback is asking for ( I have it set to a 13 amps limit which is approximately 1600 watts input). It seems that when I run on NG, the output is lower and thus the demand to the Outback is not met. This is when the Charging power goes down a little and the AC loads climbs higher. Perhaps because the generators output is surging a bit?

I think the problem with the lower output with the EU2000 on NG is due to a fitting used to adapt 2 different hoses (part of the kit) The diameter of the fitting is only about 1/8", which could be restricting the fuel flow into the carb.

NorthGuy

Re: Generator on Propane/NG Issue

northerner wrote: »

Another observation. I ran the generator on gasoline this morning, which allows the generator to put out a full 1600 watts continuous. The mate shows the proper load when the generator is able to meet the demand the Outback is asking for ( I have it set to a 13 amps limit which is approximately 1600 watts input). It seems that when I run on NG, the output is lower and thus the demand to the Outback is not met. This is when the Charging power goes down a little and the AC loads climbs higher. Perhaps because the generators output is surging a bit?

It should be lower. Generac derates their generators on NG compared to LP by 10-15%, which is in-line with what you're getting. They also say that the quality of NG might be low, in which case further derating is needed.

northerner

Re: Generator on Propane/NG Issue

I tried dropping the AC input from 13 amps down to 12 and then 11, and the loads showed lower and charging output showed higher than the original output limit of 13 amps! Seems to be a bit of an issue when the generator is not able to supply what the charger is asking for. And of course the generator runs smoother as well.

northerner

Re: Generator on Propane/NG Issue

NorthGuy wrote: »

It should be lower. Generac derates their generators on NG compared to LP by 10-15%, which is in-line with what you're getting. They also say that the quality of NG might be low, in which case further derating is needed.

I agree, but shouldn't this generator be able to put out 2000 watts for short periods? That is why I thought it may still be able to put out 1600 watts continuous on NG. It is able to on propane.

NorthGuy

Re: Generator on Propane/NG Issue

northerner wrote: »

I agree, but shouldn't this generator be able to put out 2000 watts for short periods? That is why I thought it may still be able to put out 1600 watts continuous on NG. It is able to on propane.

What is your altitude? It may need altitude derating too.

northerner

Re: Generator on Propane/NG Issue

NorthGuy wrote: »

What is your altitude? It may need altitude derating too.

About 2000 feet.

northerner

Re: Generator on Propane/NG Issue

The Honda EU 2000i is rated for a 1600 watt output continuous and 2000 watt output for 30 minutes. So if I'm getting 1400 watts max, that's a 35% derating from what it should be capable of?

NorthGuy

Re: Generator on Propane/NG Issue

northerner wrote: »

The Honda EU 2000i is rated for a 1600 watt output continuous and 2000 watt output for 30 minutes. So if I'm getting 1400 watts max, that's a 35% derating from what it should be capable of?

Between the NG conversion with possiblew poor quality NG, altitude derating, and measurements errors, it sounds reasonable.

northerner

Re: Generator on Propane/NG Issue

I'm finding my EU2000 just to small to keep my system up in winter, especially since the output is reduced running on natural gas. I'm only getting about 1200 watts max out of it now. Thinking of picking up a Yamaha EF 3000 and converting it to natural gas. I could survive the winter with the EU2000 if I did the charging at the same time my panels are producing power, however, there can be long stretches with no sun!

Blackcherry04

Re: Generator on Propane/NG Issue

northerner wrote: »

I'm finding my EU2000 just to small to keep my system up in winter, especially since the output is reduced running on natural gas. I'm only getting about 1200 watts max out of it now. Thinking of picking up a Yamaha EF 3000 and converting it to natural gas. I could survive the winter with the EU2000 if I did the charging at the same time my panels are producing power, however, there can be long stretches with no sun!

I use my Honda EU 2000 to charge a lot. I have no idea how long your run time is, but I'd lower the charger and let it run for longer periods with less load and see what you think. Maybe it is to small based on your loads. I get 2 hrs runtime on a gallon of gas at 12 amps and 6-7 hrs at 6 amps output, thats a huge difference in it's efficiency. There is a whole lot of difference in 5500 rpm and 4300 with ECO.

northerner

Re: Generator on Propane/NG Issue

Blackcherry04 wrote: »

I use my Honda EU 2000 to charge a lot. I have no idea how long your run time is, but I'd lower the charger and let it run for longer periods with less load and see what you think. Maybe it is to small based on your loads. I get 2 hrs runtime on a gallon of gas at 12 amps and 6-7 hrs at 6 amps output, thats a huge difference in it's efficiency. There is a whole lot of difference in 5500 rpm and 4300 with ECO.

My batteries were at close to 50% state yesterday and I ran the EU2000 for close to 7 hours which brought them up to almost 28 volts with little loads. Issue is the charging current at around 11 amps or less AC is only about 50 amps or less @ 24-26 volts and not enough to keep the batteries healthy! I'm currently using between 4.5 and 6 kwh per day, due to the colder weather.

NorthGuy

Re: Generator on Propane/NG Issue

northerner wrote: »

My batteries were at close to 50% state yesterday and I ran the EU2000 for close to 7 hours which brought them up to almost 28 volts with little loads. Issue is the charging current at around 11 amps or less AC is only about 50 amps or less @ 24-26 volts and not enough to keep the batteries healthy! I'm currently using between 4.5 and 6 kwh per day, due to the colder weather.

You may run it during the day to combine the output with solar, which should get you into the absorption. When absorption current goes down, you can keep it on, or, if there's still enough sun, you can turn it off. You won't get a good absorption when it's cloudy, but you probably do not need it every day.

If you don't like the noise, there's no other way than going with a big generator than can charge fast. I have 10kW Generac (which in reality is 7.5kW) and similar amount of batteries, and it's barely enough to charge them.

It would be easier if you had less batteries, so the other solution might be sell one of the strings.

Blackcherry04

Re: Generator on Propane/NG Issue

northerner wrote: »

My batteries were at close to 50% state yesterday and I ran the EU2000 for close to 7 hours which brought them up to almost 28 volts with little loads. Issue is the charging current at around 11 amps or less AC is only about 50 amps or less @ 24-26 volts and not enough to keep the batteries healthy! I'm currently using between 4.5 and 6 kwh per day, due to the colder weather.

Yeah, you just don't have enough generator power.

Did you see this thread ?? I am not saying it would work, but if you wanted to take a shot and combine two different generators in parallel. It's a given two Hondas of the same size will work together that we know and I saw a comment on the Youtube video that it will work with a Yamaha and Honda. Your on your own though.

http://www.youtube.com/watch?v=t0Q0TSwKBNI

http://forum.solar-electric.com/showthread.php?21705-Microprocessor-controlled-load-sharing-on-EU3000is

papa

Re: Generator on Propane/NG Issue

northerner wrote: »

I agree, but shouldn't this generator be able to put out 2000 watts for short periods? That is why I thought it may still be able to put out 1600 watts continuous on NG. It is able to on propane.

No.

The problem is a drop in volumetric efficiency. Unlike gasoline, which enters as a liquid, the gaseous fuels such as NG & propane are ingested as a vapor. As such, they displace more incoming air, reducing VE. NG moreso than propane.

Theoretically, enlarging the carburetor should help, but too large and mixture velocity suffers and you're back to square one. The fix is a larger displacement engine or forced induction.

papa

Re: Generator on Propane/NG Issue

And this exposes a common mistake when folks buy generators. They typically select a 'gasoline' generator based on needs (watts)... then later, convert to a gaseous fuel expecting the same output - oops!!

northerner

Re: Generator on Propane/NG Issue

NorthGuy wrote: »

You may run it during the day to combine the output with solar, which should get you into the absorption. When absorption current goes down, you can keep it on, or, if there's still enough sun, you can turn it off. You won't get a good absorption when it's cloudy, but you probably do not need it every day.

If you don't like the noise, there's no other way than going with a big generator than can charge fast. I have 10kW Generac (which in reality is 7.5kW) and similar amount of batteries, and it's barely enough to charge them.

It would be easier if you had less batteries, so the other solution might be sell one of the strings.

I need the current amount of battery storage to handle the loads I have, so I definitely won't go that route. A larger generator is really what I need.

northerner

Re: Generator on Propane/NG Issue

papa wrote: »

And this exposes a common mistake when folks buy generators. They typically select a 'gasoline' generator based on needs (watts)... then later, convert to a gaseous fuel expecting the same output - oops!!

I had originally purchased the EU 2000 for temporary use and as a backup generator. My original plan was to get a larger 3000 watt generator, but was hoping to wait till next year to make the purchase. Looks like I will need it sooner rather than later! I have to admit though, the output running on NG is lower than what I had expected.

Another issue is that my inverter will only put out 82 amps max charging current into a 24 volt bank which works out to less than 2000 watts max. One could get around that using a separate 24 volt battery charger that puts out about 20 amps or so.

NorthGuy

Re: Generator on Propane/NG Issue

northerner wrote: »

Another issue is that my inverter will only put out 82 amps max charging current into a 24 volt bank which works out to less than 2000 watts max. One could get around that using a separate 24 volt battery charger that puts out about 20 amps or so.

82A*28V(typical chaging voltage)/0.85(inverter efficiency) = 2.7kW of the generator power you need. Throw in some 1kW of loads and safety margin (2.7+1)/0.8 = 4.6kW. If you want to get it on NG at your altitude, you probably need something like 4.6/0.7 = 6.6kW gasoline generator.

Since your batteries are sized to support big loads, eventually you will need to buy an inverter that can handle such loads, and this new inverter will be able to produce more than 82A, so it might be a good idea to charge generator according to overal needs regardless of the current inverter. If you do all this math with 126A (C/10 for your batteries, right?), you will come up with 9.2kW.

northerner

Re: Generator on Propane/NG Issue

NorthGuy wrote: »

82A*28V(typical chaging voltage)/0.85(inverter efficiency) = 2.7kW of the generator power you need. Throw in some 1kW of loads and safety margin (2.7+1)/0.8 = 4.6kW. If you want to get it on NG at your altitude, you probably need something like 4.6/0.7 = 6.6kW gasoline generator.

Since your batteries are sized to support big loads, eventually you will need to buy an inverter that can handle such loads, and this new inverter will be able to produce more than 82A, so it might be a good idea to charge generator according to overal needs regardless of the current inverter. If you do all this math with 126A (C/10 for your batteries, right?), you will come up with 9.2kW.

Not needed all the time though, as I do get power from the panels and it's often sunny here in winter. With about ~2.4 kw power in, I am able to bring up the batteries very fast. I'm hoping to find time and a weather window to get my other 6 solar panels in soon too! I think I'll do fine with a 3 kw generator.

NorthGuy

Re: Generator on Propane/NG Issue

northerner wrote: »

With about ~2.4 kw power in, I am able to bring up the batteries very fast.

You have 30kWh of batteries. If they're 50% discharged, you're lacking 15kWh. Even if your batteries accept it all evenly (no absorptions and all that time consuming stuff) and everything is 100% efficient, 15kWh/2.4kW = 6 hours 20 minutes. Very fast indeed.

westbranch

Re: Generator on Propane/NG Issue

northerner wrote: »

I think I'll do fine with a 3 kw generator.

Is that the full 3000w or the derated output for the Eu3000 of 2800W less 30% = +- 1960W when on NGas.

northerner

Re: Generator on Propane/NG Issue

westbranch wrote: »

Is that the full 3000w or the derated output for the Eu3000 of 2800W less 30% = +- 1960W when on NGas.

Yes, the derated output. I can always do an occasional run on gasoline as well if need be.

northerner

Re: Generator on Propane/NG Issue

Part of the problem with the reduced output with the EU2000 has to do with running the generator in a small shelter. I discovered that even though I thought it was well ventilated, there was some blow back from the exhaust and that does reduce the output. I checked the output on gasoline and it was down from around 1600 watts normally to about 1400. I had in place a 9 inch square opening that was screened, but that's not enough. I now just turn the generator so that the exhaust blows out the open door on the side and the output is back to normal. This means that I would likely be getting 1300 to 1400 watts on NG with this orientation (as I was previously).

I was planning to insulate the shelter to reduce noise and allow for preheating when about to start, by placing a heater inside. I'm also finding this generator difficult to start when cold. It stalls numerous times before finally running normally, when it's cold (ie below -10c). It was -22 C here this morning, and it stalled about a dozen times, before I got it going.

vtmaps

Re: Generator on Propane/NG Issue

northerner wrote: »

I'm also finding this generator difficult to start when cold. It stalls numerous times before finally running normally, when it's cold (ie below -10c). It was -22 C here this morning, and it stalled about a dozen times, before I got it going.

I had that problem with cold starts... it turned out to be the low oil sensor. It can be stuck until it warms up some. Some oils may be stickier than others (according to what I've read over at the yahoo forum).

I have also noticed that the generator is more sensitive to low oil level when it is cold. It only has to be down by a thimble or two, and then it will stall several times until it warms up.

Its been a few years since I've tried to start mine at temps below freezing... I keep my generator in a garage that I keep from freezing.

--vtMaps

westbranch

Re: Generator on Propane/NG Issue

After sitting for a month or so in winter, my 3000 starts after about attempt 3, the 1000 starts after the 4 th attempt. My problem is taking the choke off too soon...

(damn keyboard is in French symbols right now, no pound sign and a bunch of other stuff ÉÉÉ No question mark either...)

northerner

Re: Generator on Propane/NG Issue

vtmaps wrote: »

I had that problem with cold starts... it turned out to be the low oil sensor. It can be stuck until it warms up some. Some oils may be stickier than others (according to what I've read over at the yahoo forum).

I have also noticed that the generator is more sensitive to low oil level when it is cold. It only has to be down by a thimble or two, and then it will stall several times until it warms up.

Its been a few years since I've tried to start mine at temps below freezing... I keep my generator in a garage that I keep from freezing.

--vtMaps

Thanks for the info. I just changed oil recently and put in 5w-30 synthetic. I just checked it as well and is full. Perhaps it's just a cold issue. I thought it had something to do with frost forming in the air intake area?