Paging Red Beard ........ generator question

[fireant911]

Originally Posted by red-beard

Unless you have a specific need for 3 phase power, you do not want to buy a 3 phase unit. The USA is "Split-Phase 240VAC" Single phase power. Almost all residential houses are Single Phase 120/240 VAC.

Kholer, Generac and Briggs-Stratton are all equal in the industry. They are all easy to work on and basically 2 cylinder air cooled engines. They are pressure fed oil systems with oil filters, air filters. This is true up to the 22 kW units. I THINK there is a new Briggs & Stratton unit that is 26kW that is still air cooled. But generally, anything over 22kW is a Water Cooled, derated 4 cylinder car engine.

Generac is most popular. Stay away from the "Off-Grid" generator. It has some modes that make is screwy for a backup generator.

red-beard,
Perfect! There are many details that makes no sense to the 'common' folk - single phase it is. Thanks for the other advice as this will aid in buying one of these units (which I am NOT going to postpone... again).

[stevej37]

Gererac makes good gererators.

[Jims5543]

My 17Kw Generac is a 2004 Model that is still running without one hiccup.

I worry about the engine lasting. I change the oil every January. I replace 1/2 quart (IIRC 2 quart capacity I may be wrong here) with 1/2 quart of Lucas Oil Stabilizer.

I also give it a tune up every January, which is basically air filter & spark plugs.

I have no hobb meter on it so I have no idea how many hours it has on it. I know it has gotten me through a few several day outages after hurricanes. When that happens I try to change the oil/filter every 2 days of continuous running.

I also shut it down for a couple of hours every 12 hours to just let it cool down and give it a break.

I do not exercise it weekly, I exercise it once every 2-3 months. I should probably exercise it Monthy. I felt like the weekly exercise was too often and unnecessary. I figure the run time I saved over the last 17 years probably extended the life I have left in it.

I plan on replacing it next winter, I am trying to get 1 more hurricane season out of it.

Then I am getting another 17KW or I might look to go one size larger.

Next one will be professionally installed complete with permit. A friend who know how to install them helped me with this one with no permit. I prefer to get the next one installed with a permit so it can be listed as a selling feature on the house.

Good info in this thread, I just wanted to toss in that I have a 17 year old Generac in Hurricane country and it has served me very well.

Do the transfer switch and then put all the items in the house you do not want to have power interruptions (i.e. internet router and TV) on a UPS.

It takes about 1 minute for the house to switch over to Generator Power, it is especially nice to have the internet router on a UPS so it does not need to reset.

[rfuerst911sc]

Jims5543 what size propane tank feeds your generator ? Have you ever tracked consumption ? If you had to run for a week how much do you think it would use ?

I have a 500 gallon tank that feeds the furnace/range top/emergency wall heater and that lasts us a year . I am thinking an extra 250 gallon tank just to feed a future generator . Curious what your real world use suggests .

[Jims5543]

500 gallon tank. It seems to use 70 gallons a day. I can go almost a week of constant running before we need a refill. Wish I went with a 750+ tank.

If a storm was really bad and we know propane delivery is going to be hard to get. We will shut it off for extended periods to postpone the need for a delivery.

Sent from my SM-G781U using Tapatalk

[rfuerst911sc]

Originally Posted by Jims5543

500 gallon tank. It seems to use 70 gallons a day. I can go almost a week of constant running before we need a refill. Wish I went with a 750+ tank.

If a storm was really bad and we know propane delivery is going to be hard to get. We will shut it off for extended periods to postpone the need for a delivery.

Sent from my SM-G781U using Tapatalk

70 gallons a day is a thirsty little 👿 . I appreciate the real world feedback . I think I would let a generator run for a few hours then turn off for a few hours . It would really stink to have the convenience of a generator during an extended outage and run out of propane ☹️.

[Evans, Marv]

It's for that reason I'm seriously considering a diesel if I opt for a whole house generator. For my place, I think that would work out the best.

[rfuerst911sc]

Originally Posted by Evans, Marv

It's for that reason I'm seriously considering a diesel if I opt for a whole house generator. For my place, I think that would work out the best.

I some what agree , however when I look on CL and fleabay most of the reasonably priced diesel's are 7.5 kw or maybe 10kw . Not enough juice for me . At a bare minimum I need 13.5kw to 15kw to do what I want .

[Evans, Marv]

Yes, my house is all electric with 7 tons total of heating/air conditioning. I think I would need something like 25kW, and would have to make a pad for it down by my main panel. I know I hit 100A once years ago during winter when I had lights on, the oven running, & both heating units kicked on at the same time.

[red-beard]

Originally Posted by rfuerst911sc

70 gallons a day is a thirsty little 👿 . I appreciate the real world feedback . I think I would let a generator run for a few hours then turn off for a few hours . It would really stink to have the convenience of a generator during an extended outage and run out of propane ☹️.

See, this is the advantage of the Battery/Inverter/Generator system

When the generator is running, it is running nearly full load, to re-charge the batteries plus run the house. When the batteries hit about 80% full, the generator shuts off. The batteries then drain down to about 30% and the cycle starts again.

Why 30% to 80%?

Batteries do not fill up linearly near the top end of the fill. And near the bottom, they are more likely to be damaged/create tendrils, etc. You can get a lot more life out of a battery that is kept at 80%.

[rfuerst911sc]

^^^ Redbeard in your scenario above how large does the generator have to be ? I know that's not a single answer covers all scenarios but for a 1600 sf single story house with a 3 ton 18 SEER dual fuel AC/heat and electric water heater and well pump . I guess asked another way an one get buy with a smaller generator ( less fuel ) .

[Arizona_928]

Originally Posted by rfuerst911sc

70 gallons a day is a thirsty little 👿 . I appreciate the real world feedback . I think I would let a generator run for a few hours then turn off for a few hours . It would really stink to have the convenience of a generator during an extended outage and run out of propane ☹️.

That's just how them gas units go. 6k Diesel would see 70 gallons go on 5+ days depending how much load. Higher buy in up front though.

[Arizona_928]

Originally Posted by red-beard

See, this is the advantage of the Battery/Inverter/Generator system

When the generator is running, it is running nearly full load, to re-charge the batteries plus run the house. When the batteries hit about 80% full, the generator shuts off. The batteries then drain down to about 30% and the cycle starts again.

Why 30% to 80%?

Batteries do not fill up linearly near the top end of the fill. And near the bottom, they are more likely to be damaged/create tendrils, etc. You can get a lot more life out of a battery that is kept at 80%.

Can you get access to solid state batteries yet?

[red-beard]

Not yet

[Jims5543]

Originally Posted by Arizona_928

That's just how them gas units go. 6k Diesel would see 70 gallons go on 5+ days depending how much load. Higher buy in up front though.

I was a little skeptical of you claim on 70 gallons over 5 days.

So I went here:

https://www.hardydiesel.com/resources/diesel-generator-fuel-consumption-chart/

Seems running a 17 kw diesel generator 24 hours a day would require about 1 gallon an hour or 120 gallons in 5 days. *edit* - That would be comparing apples to apples.

*edit* - you are correct a 6KW (which would not work on my house it is too small) running at 75% load would burn about 1/2 gallon an hour or 12 gallons a day or 60 in 5 days. Except, I am giving my usage for a 17KW unit running at 50-60% load.

A diesel is much more efficient than the 3 gallons an hour a Propane Generator requires, that is for sure.

The nice part about the propane is, you do not have to worry about storing it.

I have not needed my Generator for 2 years now. The propane in that tank is that old. While a Diesel would be a much more efficient choice when needing it all the time, the propane makes for sense for occasional needs.

In a perfect world, I would love to have solar / battery, except I am not convinced the solar will be there after a cat 3 or 4 storm.

I am also not keen on having to pull it down for the storm then installing it after the storm.

Some day I will have solar / battery, not on this house, it will be on my house on acreage so I can be off grid if I desire to.

[fireant911]

red-beard,
Thanks for your willingness to share your knowledge AND your patience with those of us that are eager to know more! I was a bit shocked when jims5543 stated that his propane generator appeared to use 70 gallons of propane a day but after investigating further that is in line with estimated hourly consumption. Like others have stated, a diesel engine may be much better suited for this application; however, diesel configurations are way more expensive... unless the unit providing the power is already available (think - tractors).

I was speaking with my younger brother this morning regarding this generator quandary and he mentioned using my tractor with a pto-driven generator head. A quick search revealed that these heads can be purchased much cheaper that the cost of a complete propane-fueled package. During my search I discovered that issues may arise from the usage of pto-driven generators - Tractor-Driven Generators: Producing Quality Power

Would you share your thoughts about diesel pto-driven generators (or did I already answer my question with the link above which quite clearly lists a plethora of cautionary warnings about such configurations)?

[fireant911]

Originally Posted by red-beard

See, this is the advantage of the Battery/Inverter/Generator system

When the generator is running, it is running nearly full load, to re-charge the batteries plus run the house. When the batteries hit about 80% full, the generator shuts off. The batteries then drain down to about 30% and the cycle starts again.

Why 30% to 80%?

Batteries do not fill up linearly near the top end of the fill. And near the bottom, they are more likely to be damaged/create tendrils, etc. You can get a lot more life out of a battery that is kept at 80%.

red-beard,
Where can one read up more on the Battery/Inverter/Generator system you mentioned above?

[Arizona_928]

Originally Posted by fireant911

red-beard,
Thanks for your willingness to share your knowledge AND your patience with those of us that are eager to know more! I was a bit shocked when jims5543 stated that his propane generator appeared to use 70 gallons of propane a day but after investigating further that is in line with estimated hourly consumption. Like others have stated, a diesel engine may be much better suited for this application; however, diesel configurations are way more expensive... unless the unit providing the power is already available (think - tractors).

I was speaking with my younger brother this morning regarding this generator quandary and he mentioned using my tractor with a pto-driven generator head. A quick search revealed that these heads can be purchased much cheaper that the cost of a complete propane-fueled package. During my search I discovered that issues may arise from the usage of pto-driven generators - Tractor-Driven Generators: Producing Quality Power



Would you share your thoughts about diesel pto-driven generators (or did I already answer my question with the link above which quite clearly lists a plethora of cautionary warnings about such configurations)?

If you have an old tractor you don't mind putting a ton of hours on. I would go for it. You would also look at the # of poles on the generator head. 3600 rpm vs 1800 rpm.

Most of these applications are DIY. Buy a used or new 4 pole generator head. Mount on a frame and hook up a pto drive shaft and splines on the head. similarly harbor freight and eBay have units that are plug and play. Personally that is the last thing I'll be using my tractors for. Especially the new one. The cost per hour on the tractor is 4x that of my old pancake 6kw head and a 1l Kubota engine.

[red-beard]

The best way to reduce the operating cost of a generator is to reduce the size. You want to run up the load curve as much as you can. Part load is inefficient.

The best way to reduce the generator size is to use soft starters on the air conditioners and any motors, to reduce in-rush current.

I have two large air conditioners (4 ton and 3.5 ton). I only have a 16 kW generator. It will start and run both because of the soft starts. A soft starter allowed an 8kW unit to start/run a 3 ton air conditioner.

Get the smallest unit you can so that you will do what you need. This will minimize fuel consumption.

[red-beard]

Originally Posted by fireant911

red-beard,
Where can one read up more on the Battery/Inverter/Generator system you mentioned above?

Mi-Grid Hybrid Energy System

I'd send you to our other website, but it is about to be shutdown.