Need recommendations for a 6000 watt generator compatible with 2 wire auto start

buggeyes

Hi, We are off grid newbies, we bought a house that was all set up and ready to go. Lucky us! So we are still learning everything.
The previous owner went the manual route for a generator and we want to get one that we can hook up to our trace converter/charger with autostart (that way we can go on vacation in inclement weather and not worry about our battery bank). So yesterday I read lots of forum posts and talked with many local businesses and I still cant get what I want, which is a simple answer of, Go get this "brand & model" generator!
The local solar company that will be installing the auto start for us said we need to buy an "auto start module to do a 2 wire start"
I had finally narrowed it down to a Honda em6500sx when, after reading here, it appears they are 3 wire.
We have propane now, so that would be convenient but we are open to any fuel option.
Ive tossed the idea of Generac's EcoGen but Ive heard/read too many negative reviews about them.
Please give me some ideas of great Generator options! Thanks!

BB.

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Welcome to the forum Buggeyes,

I always like to ask lots of questions first...

1) how much load do you need to support (watts/kWatts and 120 or 120/240 VAC power, etc.)?
2) how big of battery bank (Voltage and Amp*Hours, flooded cell or AGM, etc.)?
3) how big of solar array (watts) and type of charge controller)?
4) where are you at (cold/hot/4 seasons)?
5) full time house or seasonal?
6) backup to the backup genset?
7) cost/availability of fuel. Storage of fuel. Do you have other fuels on site?

Larger generators really "drink" fuel. Ideally, you want to run the genset most of the time around 50% to ~80% of rated power (for best fuel economy). and Diesels needs somewhere around 40-60% minimum loading.

"Too large" of gensets (running at 25% or less load) just burn fuel and may not even last as long.

-Bill

Texas Wellman

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

http://dietschmanufacturing.com/

northerner

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Atkinson Electronics makes a 2 wire to 3 wire generator start module. That way you can use any generator that requires a 3 wire start, with a 2 wire start command.

http://atkinsonelectronics.com/

As for the generator, either a Honda or a Yamaha are good choices, and they can be converted to run on propane or natural gas.

One other important thing to consider when running on either propane or natural gas, is NOT to switch off the ignition with the control module. The gas supply must be shut off in order to shut down the generator and is done with a solenoid controlled valve in the gas line

buggeyes

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Here are our specs as requested by Bill:
1) how much load do you need to support (watts/kWatts and 120 or 120/240 VAC power, etc.)?
I imagine 4000 watt since our trace inverter/charger is 4000 watt model
2) how big of battery bank (Voltage and Amp*Hours, flooded cell or AGM, etc.)?
We have 16 qty Rolls Surrette S 530
3) how big of solar array (watts) and type of charge controller)?
16 qty 85 Watt panels; rv power products solar boost 3048
4) where are you at (cold/hot/4 seasons)?
Northern Calif, not too cold, but can get very hot
5) full time house or seasonal?
Full time house
6) backup to the backup genset?
? None? Done know
7) cost/availability of fuel. Storage of fuel. Do you have other fuels on site?
Propane is there, We would just store diesel or gas if we went that route.

BB.

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Ok--Let's see where this leads us.

• The inverter is probably this Trace 4048 120 VAC inverter with 60 amp 48 VDC battery charger.
• The 16x batteries are flooded cell 6 volt @ 400 AH (C₂₀ hour rating). 8x 6 volt batteries in series in 2 parallel strings or 48 volt @ 800 AH rating.
• 16 panels * 85 watts = 1,360 Watt solar array (Solar Boost 3048 should be "big enough" for this array @ 48 volt bank).

Since we don't have any AC loads defined--I will start with the battery bank as the base for the system definitions. First, how much power can the bank supply assuming our standard rules of thumbs:

• 48 volt * 800 AH * 1/2 days of storage * 0.50 maximum discharge * 0.85 inverter eff = 8,160 WH = 8.2 kWH per day "nominal" 120 VAC output
• 48 volts * 800 AH * 1/20 hour discharge * 0.85 inverter eff = 1,632 Watt "average load"
• 48 volts * 800 AH * 1/8 discharge * 0.85 inverter eff = 4,028 Watt "peak average load"
• 48 volts * 800 AH * 1/2.5 discharge * 0.85 inverter eff = 13,056 Watt "max surge load" (limited to ~8,000 Watts by inverter design)
• 60 Amp inverter battery charger * 1/800 AH batter bank = 0.075 = ~7.5% rate of charge (probably on the low side for charging current--5% to 13% with 10-~20-25% recommended charging rate for deeply cycling battery bank)

So, the Battery:AC Inverter seems to be a good match (using rules of thumbs). Next, charging the battery bank.

There are two methods that should be followed to properly recharge the battery bank. The first is sizing the solar array based on the actual size of the battery bank (larger battery banks need more charging current). The typical starting points are 5% to 13% rate of charge. The second is to ensure the battery bank is fully recharged on a "nominal" sun and power usage day.

First sizing array based on size of battery bank. A good rule of thumb is 5% minimum (lightly cycled battery bank) to ~13% rate of charge (heavily cycled and "optimum use of solar array + charge controller hardware). 10% rate of charge is a healthy nominal size of array:

• 800 AH * 59 volts charging * 1/0.77 panel+controller losses * 0.05 rate of charge = 3,065 Watt Array Minimum
• 800 AH * 59 volts charging * 1/0.77 panel+controller losses * 0.10 rate of charge = 6,130 Watt Array Nominal
• 800 AH * 59 volts charging * 1/0.77 panel+controller losses * 0.13 rate of charge = 7,969 Watt Array "cost effective maximum"

And then based on the amount of power you use and available sun per day... Using PV Watts for Sacramento California, fixed array tilted to latitude (~38.5 degrees from horizontal):

Month    Solar Radiation (kWh/m 2/day)
1      2.75     
2      4.23     
3      5.27     
4      6.33     
5      6.83     
6      6.93     
7      7.23     
8      7.30     
9      6.96     
10      5.67     
11      3.68     
12      2.71     
Year      5.50

Toss the bottom 3 months and we get February at 4.23 hours of sun per day as the "break even" month (off grid, use generator during poor weather). Assuming 8,160 WH per day "average" power usage (you may have widely varying power needs--A/C and water pumping in summer, much less power usage in winter)--Anyway, a sample calculation would look like:

• 8,160 Watt*Hours per day (based on size of battery bank and 25% per day usage) * 0.52 system efficiency * 1/4.23 hours of sun = 3,710 Watt Array minimum for February

So based on my SWAGs--Your 1,300 watt solar array is way too small to support this battery bank--At a minimum you should be looking at 3,065 Watt array. And 6,130 Watt array would not be out of place either...

Again, not knowing your loads (A/C and water pumping in summer, vs possibly some heat pump use in winter, etc.)--Really need to know more about your power needs... And if this home is "new to you"--It may take you awhile to figure out what your daily loads may be (energy use is highly personal--What works for me, on grid, or somebody out in the wilds of Canada, like our other two moderators, may not work for you).

Measuring your loads with a Kill-a-Watt type meter (or larger one if you have large loads) is really needed here.

Sizing the genset... To support the 60 Amp battery charger, with "typical deratings", roughly (these are guesses on my part):

• 60 amps * 59 volts * 1/0.80 charger eff * 1/0.7 PF * 1/0.80 generator derating = 7,902 Watt nominal rated genset

If you have more efficient (more modern AC inverter/chargers with Power Factor Correction), you might see the same current rating as:

• 60 amps * 59 volts * 1/0.90 charger eff * 1/0.95 PF * 1/0.80 generator derating = 5,175 Watt nominal rated genset

Note, the Inverter/Charger you are using is probably a 120 VAC only AC input--So, to use the maximum available curent from the genset (30 amps at 120 VAC?), you would need a genset capable of outputting 30 amps (or more) on a single 120 VAC phase output... Not all gensets are capable (many will split 1/2 of their output wattage across the 120/240 split phase output--or for a ~4,500 watt output genset, ~15 amps on Line A 120 VAC and 15 amps on Line B output).

To use the entire output of a 120/240 VAC larger genset, you may need a 240 to 120 step-down transformer.

Today's modern inverter/chargers in the larger power sizes are now available in 120/240 native split phase output (or stacked pairs of AC inverter/chargers in some cases).

Your other option would be to use a separate AC to DC battery charger (approximately 80 to 160+ amps are "doable")...

Fuel wise, propane is great if you already have a large propane tank and good fueling prices (long storage, single fuel delivery, etc.). Diesel may not store as well (water in fuel, algae). Gasoline does not store more than a year.

Diesel gensets in California are coming under very stringent regulations--Check how that may affect you in your region/use (if permits are required, may be very difficult to get approvals for diesel). If you will use gasoline for cars/farm usage--then sharing with genset would be interesting (again, fuel storage, spill prevention, etc. are all "ugly" in "official California land").

Anyway, probably more questions than answers. What are your thoughts/needs/questions.

-Bill

buggeyes

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Wow Bill, very thorough! I have some studying to do. We were thinking of changing out the 16 85 watt panels for 8 250 watts, but that is still only 2000 watts. and i think our priority as far as money will be the generator.
Im going to take this to our local solar tech so he can help explain this to me. If I/we have any other questions I will be sure to post.
And thanks Texas Wellman for your recommendation, it looks like it what I was looking for before Bill thru a wrench in my simple but now complex question.

BB.

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

On thing you should do is study about batteries:

http://www.windsun.com/Batteries/Battery_FAQ.htm
http://www.batteryfaq.org/
http://batteryuniversity.com/

Basically, you need to see what the state of charge of the battery bank is right now... There is a good chance that the batteries are undercharged and potentially sulfating. It can take weeks-months to kill the battery bank if it is not properly maintained/cycled.

If you battery bank is not properly charged, a genset+battery charger and many hours of run time + gallons of fuel may be ahead for you. As you get the battery recharging, you should also review your present solar array and see if it performing correctly or if it needs work too (plus a larger array+charge controller).

So, a hydrometer and a DC current clamp + DMM meter would be a good beginning.

-Bill

BB.

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Also, I should add that my numbers are not handed down from God... They are rough guesses and are there to give you an idea of what you should expect from your system--Simply a starting point for discussions.

-Bill

vtmaps

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

buggeyes wrote: »

The previous owner went the manual route for a generator and we want to get one that we can hook up to our trace converter/charger with autostart (that way we can go on vacation in inclement weather and not worry about our battery bank).

Welcome to the forum,

There is a lot to be said for manual control of a power system. I would worry more about my batteries if I had an AGS.

Living off-grid means constant vigilance. Bad things can happen to good equipment... Has your charge controller decided to start cooking your batteries? Do you have a shorted cell in one battery? (in which case most charging current is going through the bad battery at the expense of the good parallel battery). Has the temperature compensation sensor slipped off the battery? There are a million things that can go wrong.

When you automate your system you don't notice that there are problems until the lights go out, and by then the damage has multiplied. For example, consider the example of the shorted cell in one battery. This will cause an accelerating decline in your entire battery bank. But you won't know what's going on because your generator takes care of things. Of course you may notice that your generator is running more often, or you may not. Maybe your generator will run so much that it runs out of fuel, or its low oil sensor shuts it down.

If you go on vacation in inclement weather, what will your loads be like? Many folks can reduce loads to an essential baseline while they are away. Example: my refrigerator operates on DC. When I go away, I shut off the inverter. With only a refrigerator (in a cool house) to power, my solar panels can provide enough to run the fridge even on a cloudy day. One thing I do whenever I travel is worry about my batteries. I would worry more if I was counting on a complex, programmable, potentially buggy, electromechanical system to maintain my batteries.

--vtMaps

westbranch

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Just add a bit more complexity to the issue, Do you have a hydrometer? I didn't see it mentioned in your post on a quick scan.. If not you NEED one. It would do you good to get a Specific Gravity ( SG ) reading right now, on each cell, (ps write them all down and number your cells) so you have a base line to work from once you get more panels or a generator, as you started this thread with.

HTH

buggeyes

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

We have a brand new battery bank, we replaced it ourselves about 2 months ago and I had a local solar tech come out a month later and show me how to maintain them. he didnt suggest using a hydrometer (which the old owner left behind) but he did suggest getting a monthly voltage reading and plotting that out. Which, today is my scheduled day for that. I guess he was trying to keep it simple.

SolarMusher

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

buggeyes wrote: »

We have a brand new battery bank, we replaced it ourselves about 2 months ago and I had a local solar tech come out a month later and show me how to maintain them. he didnt suggest using a hydrometer (which the old owner left behind) but he did suggest getting a monthly voltage reading and plotting that out. Which, today is my scheduled day for that. I guess he was trying to keep it simple.

Trying to keep it simple might be a bad idea, to "trust" a voltmeter you'd better have checked specific gravity before, especially with Rolls.

Blackcherry04

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

buggeyes wrote: »

We have a brand new battery bank, we replaced it ourselves about 2 months ago and I had a local solar tech come out a month later and show me how to maintain them. he didnt suggest using a hydrometer (which the old owner left behind) but he did suggest getting a monthly voltage reading and plotting that out. Which, today is my scheduled day for that. I guess he was trying to keep it simple.

A Guess would be that the bank probably was not commissioned and batteries not equalized to each other before you started using them. After a couple months you are heading to a place where 100% recovery becomes a issue if they are sulfated. Get your SG reading's and post them here and you can get some help if you need it.

SolarMusher

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

I agree with Blackcherry. My last new S-530 bank needed more than 12/15 hours EQ before SG rised to 1.275.
Check your level for the next time you 'll have to fill them by yourself and do not overfill if you want SG to be accurate. That's a common mistake made by several new batteries owners.

buggeyes

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Attachment not found.
Ok, attached is the battery chart of our 16 bank battery. Sorry this took so long! And hopefully it makes sense. I turned off the power for 1/2 hr and then used the hydrometer. If it matters it was about 3:30 in the afternoon. I believe its a 48 volt system in 2 series. the top row and row #3 is one series and row #2 & 4 is the 2nd series.
Any suggestions/recommendations are welcome

stillchillin

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

Bug, I have been there and done that first and for most EQ the crap out of your battery bank with whatever means you have make sure the water level is good and check it often. It may take days to see an improvement. Make sure the temperature of your batteries does not exceed 50 C.( for rolls you did not specify model Rolls has a nice site so you can look up specs) Make sure you charge your bank to 100% before you start your EQ. EQ voltage will probably be 64 Volts but check first. It may make sense to EQ one half of your bank at a time if you don't have a large enough genset you may not reach a good EQ voltage. I had a severely sulfated bank 1125 SG and I brought it around it took time. Rolls site is good get the manual for your batteries and set your chargers up to the book. The genset I also considered generacs "solar generator" They don't have it figured out yet IMO. I got the 8KW standby and use it with a AGS I can tell you how I did it if you decide to go that way. Stillchillin

xolar

Re: Need recommendations for a 6000 watt generator compatible with 2 wire auto start

So I was the lucky guy to go out and help Rachel with her off grid system and just wanted to let the rest of know the skinny. The place they bought is amazing, it is one of the few owner built places that I have left thinking I want to build one of those. The system is a trace 4048 so it was easy to tie RY7 into the 2wire start of the Dietsch Manufacturing's 2 wire start, I also set it up so the could use a toggle switch for easy manual starting and added a easy connect for a manual start in the house. I don't typically use a generator like the Diestsch which I would consider a portable and the system itself is only benefiting from the 120 outlet on the generator since it is a single unit, I have a customer with a brand new trace 4048 sitting in a box that will help there system out big time. Does any one else have experience with this unit? I know it was recommended here so has it been used more than once? have a good weekend.

Xolar