propane auto switch backup generator

[Toyboy]

I知 no fan of Generac but I will say that every brand of LP or Nat gas engine has moisture issues in the cold, it痴 just physics. These fuels have less hydrocarbon and burn more completely creating far more water in the exhaust which also finds its way into the engine.

Some other brands sell optional electric breather heater kits in cold climates to prevent this. A big problem is people buying these products online and shipping them to other climate zones. We run into the same issue regularly either because someone bought it through Costco or HD online and either don稚 have the heater kit, or often in the off grid applications won稚 connect it because it痴 a continuous 40watt draw on their system. They often won稚 connect the battery charger either, then scream lawsuit when it doesn稚 start and their remote cabin freezes solid.

I have no idea if Generac has a breather heater kit but always being the bottom dollar supplier don稚 expect anything but the absolute basics. Buying from a knowledgeable dealer might avoid this but around here anyone with a PO Box or lawnmower sharpening business can be and are Generac dealers.

I don't believe that is a true statement. To work on Generac units you have to go to their tech school. A lot of electrical/electricians can do the install but for mechanical you have to have a Generac tech.
For my 20kw unit install I first had to have the NG company come out and swap out my meter for a larger capacity/volume meter
Then the Electrical contractor that I purchased my unit from came out and did the install.
Then I had the plumber to do the piping/regulator.
Then the contractor came back set it up/tested it and we've been one happy family since.
The one thing to make sure of is pick a contractor can do the install and mechanical. Saves lots of headaches.
Finally no on the breather heater, but they do have oil and battery heater. Mine fired up at -28 deg so it does do the job.
My total cost labor included was under 4.3k

 

[grsthegreat]

I don't believe that is a true statement. To work on Generac units you have to go to their tech school. A lot of electrical/electricians can do the install but for mechanical you have to have a Generac tech.
For my 20kw unit install I first had to have the NG company come out and swap out my meter for a larger capacity/volume meter
Then the Electrical contractor that I purchased my unit from came out and did the install.
Then I had the plumber to do the piping/regulator.
Then the contractor came back set it up/tested it and we've been one happy family since.
The one thing to make sure of is pick a contractor can do the install and mechanical. Saves lots of headaches.
Finally no on the breather heater, but they do have oil and battery heater. Mine fired up at -28 deg so it does do the job.
My total cost labor included was under 4.3k

there is a breather kit available. Generac part 7103

 

[Toyboy]

there is a breather kit available. Generac part 7103

Thank You, that option was never mentioned when I purchased my 20kw 6 years ago.

 

[dnw64]

...Ours operates off of LP, rated fuel usage at half load is 1.89 GPH, and 2.9 at full load. Figuring on 80% fill of a 500 gallon tank, unless my math is off, we can run it almost 10 days continuously at 50% loading.

Your math is about right (it's actually just under 9 days). HOWEVER you started with erroneous input. The tank is "full" at 80% water capacity, however you cannot use it all, for the same reason they don't fill to 100% capacity. Evaporation rate.

Usable capacity (at rated output) of a propane tank is only 60% of the water capacity. The surface area when above 80% or below 20% will not support the necessary evaporation rate. Of course, if it's summer time you may be able to go a bit below 20% before you start starving the genset, but it's best to not plan on it.

Bottom line, at 1.89 GPH, you should only plan on a "full" 500 gallon tank lasting about 6.5 days.

One thing I'm not sure of is why gensets aren't designed to handle liquid propane, like forklifts. That way you could use 95% or more of the propane before running out.

 

[ronjhall]

Deleted

 

[shooterdon]

I was just quoted $8200 installed for a 16kw. It seems high to me. The ATS and generator are going to be near the pole for my incoming supply about 100 ft from the house so no trenching for the cable run. Propane line is 50 ft away. Generator and ATS were half the cost. So about $4000 to install. A one day job I imagine...what am I missing?

 

[nbking]

Mine took three separate days. First day they did the propane trench about 75', then capped it and let the pressure sit for 24 hours, inspector came the next day looked at the trench pipes etc. The next time they came out, brought everything, generator, ats and had it all installed, took the whole day. Inspector came the next day and looked everything over and signed off. Third day was fast, one guy showed up and did all the checks, called it in and got it running etc. Was pretty fast and organized.

 

[dnw64]

I put in a 20KW Cummins this past summer.

Genset was $4400
Propane was $1650 (I had to install a new 500 gallon tank, about 100' away). Cost included the rental of a trencher. Due to bedrock there was much of the line that could not be set at -18", and about 30' that could not be set at -6". Did not cover the cost of sleeving the line with schedule 80 pipe to protect the line, since they quoted me a "not to exceed" price for installation. Did not include the cost of me having to cover up the less than -6" part of the run.
Electric was $2200. There was already a (manual) transfer switch installed, so it just had to be replaced and then run to the new genset location (about 75' cable run).
Total $8250

I did the pad, bought the genset direct, and placed/secured it myself.

So yeah, plan on double the genset cost as a rough starting point.

 

[Chilliwack Murray]

.

One thing I'm not sure of is why gensets aren't designed to handle liquid propane, like forklifts. That way you could use 95% or more of the propane before running out.

All larger LP units are liquid, it’s not practical to pull more than 20kw of vapour from a tank continuously in low temperatures and when the liquid LP gets below -40 there is no vapour produced. Onan consumer units have typically been available in vapour or liquid all the way down to 4kw. Air cooled have a vapourizer wrapped around the exhaust manifold. Liquid cooled use a traditional vapourizer with coolant supplying the heat.

Unless you have an electric heater keeping the vapourizer warm, you may not be able to start either in the extreme cold though.

 

[dnw64]

All larger LP units are liquid, it’s not practical to pull more than 20kw of vapour from a tank continuously in low temperatures...

Very interesting. Thanks!