The AM Forum

Looking at buying a home generator for the QTH, have been checking out the Kohler series.
Want something to auto-switch if I am not there, run the house and radio shack/barn.

I was quoted on Kohler 14RES.

Opinons on Kohler units, pro/con?

Was quoted on a 14KW unit, wondering I am better with a 20KW?

Any other fine points to consider, ask or ponder on?

Thanks - Bruce

I design quite a few large generator systems, and every now and then a small residential system.

Kohler is a good generator and they make a good residential option. I have always considered them slightly behind Cat and Cummings but not far. They are way ahead of the Generac and similar generators.

You are looking at a very good system - not a Home Depot special - and going up to 20 KW won't cost that much more.

Have you had someone run a computer study of your load and especially a study of how much HVAC compressor starting load that you have? Starting a HVAC compressor takes a lot of KW and usually when you have this covered - you have a good bit of resistive type load capacity left over.

I find that many electrical contractors just add up the load and select a genset and get into real trouble. A motor laod takes about 600% of running load to start and if the genset can't deliver - you have a problem. If you have two compressors you can step start one - then another and save some capacity. This is easy to do with a time delay on one compressor unit.

Pat
N4LTA

Pat said:
Pat, I'm curious as to your preference: propane or fuel oil?

We lose power an average of one a week.  We installed a Kohler 12RESNT w/propane.

We have two 1000gal tanks.

Except for the range, and the geothermal system, we have b/u per to all circuits.

We can heat with wood.

Even the LUSO crank up tower is backed up.

We have carb and battery heaters and the auto exercise board installed.

Love the autostart.

Thanks guy, exactly the feedback I was looking for!

Pat, don't think I could picked a better person to ask, wow, was that taylor made or what?
To answer your question on A/C, no A/C in the house, not common in Maine, and my place was built in 1860 anyway, not well suited for A/C. We are moe concerned about staying warm!

What I do have is a midsize boiler for radiant heat, and other normal loads like a fridge, washer, gas dryer, water and sump pumps,netc. The rep suggested a 14 KW unit, but agreed a 20 KW might be better if we plan an addition, cost difference is a little less than $1K. Claims larger units use less fuel than a smaller unit working near max load?

The contractor is telling me that it is better to put the unit on a pressure treated 4 x 4 wood on top of crushed stone, rather than a concrete pad. Claims that concrete will move with the ground freeze/thaw. Your thoughts?

We do have propane, hope you think Kohler is still ok! Mike wondered about your preference on thus as well. We've got a large underground propane tank which powers the cookstove and boiler.

Again, appreciate the help fellows!

- Bruce

W1UJR - A Tad Off The Beaten Path
(http://www.w1ujr.net/images/DSC01326.jpg)

Diesel: downside is cold weather/ fuel gelling up
Gasoline: downside is fuel gets stale
Propane: downside is delivery by supplier


I understand the hot ticket is to get propane with adjustable jets and fuel switchover with connections for external LP Gas canisters like for outside BBQ grills.  Lets you bridge if the delivery truck can't get there for a while, like in our snows here last winter.

I had a Kohler 3.5KW 1800RPM gasoline unit and was happy with it. I sold it only because I bought a Mankato 40KW diesel machine to run the whole house. It is 2X overkill but it was cheap. Oversize is important for both voltage regulation and frequency regulation if you have A/C. Even on the 40K, you can tell when the compressor starts. But it seems you don't have such difficult loads so you ought to do well. In Texas, never seen diesel gel yet.

The real choice was between diesel and natural gas. Natural gas has yet to ever be interrupted and it is cheaper than diesel. I've been told a diesel set can run on (switch over to) natural gas, and also been told it cannot.

I don't have to worry about fuel oil gelling either. I was thinking more along the lines of the fuel for the furnace and using it, (the only difference between is diesel you pay fuel tax). We have both at work and they do equally well. I have fuel oil for the furnace and propane for both the fireplace and the stove. We can get by with fans in the summer so the A/C isn't an issue. Its the water pump, furnace, fridge necessities that are important. We lose power here often and for lengths of time. The heat is the real important thing in the winter.

Is it legal to use fuel oil in a generator? If I recall correctly home heating "oil" is highly refined diesel or sometimes called karosene. If the use of heating oil is legal and heating oil is available at a reasonable price in your area it might be worth considering.

When you look at gas powered generators it seems that power output for a given size engine is highest with automotive gasoline, Natural gas is less and propane is at the bottom. The advantages of natural gas and propane is a very clean burn.

The best bang for the fuel buck is diesel. It seems to me most diesel gen sets run at a much lower rpm because of the lower rpm torque. Heating oil is very well stabilized for low temperatures so jelling doesn't occur. I would think a diesel gen set for fixed home or farm use would have a block heater available (as should a gas set) to make cold starts easier. My choice would be a diesel set IF heating oil could be used.

I have to admit, I really like diesel power. I have been driving diesel powered vehicles for 20 years now. I wouldn't hesitate to use a modern diesel generator. Newer high tech diesel engines are very clean burning. Add the use of the very low sulfur heating oil (if it's usable) and it's a no brainer.  Your home may even have a left over tank.

My 2 cents worth.
Mike

The best fuel by far is diesel. The diesel has much more starting torque and step function torque than an ignition engine. But with that said  - cold weather is a problem with diesel.

Natural gas and propane work well and gasoline also but athere are some safety and electrical code issues with gasoline tanks and storage. If natural gas is not available - propane would be my choice.

The NFPA allows for propane and diesel fuel for emergency systems but natural gas only with permission from the athority having jurisdiction because it can be interrupted in an emergency.

You have an ideal situation in that all of your load is close to being resistive and so you can use a small genset and not worry about motor starting. If you had a couple of 3 ton AC units you would probably need a 30 KW unit.

We put them on a concrete pad here in SC, but I'd go with your local contractors advice as we don't get the ground freezing here any deeper than an inch or so and for no more than a week.

I just designed a system for a large house using a diesel system. He needed a 40 KW system and it was very expensive. We priced a Cummings diesel system. At that load, three phase would be preferable but he has a single phase system.
He had been looking at the Home Depot Generac systems and was very surprised at the cost.

Thanks Pat!

You mentioned Generac systems, I noticed the sales rep had both Generac and Kohler stickers on the side of his truck. I asked him why he quoted on Kohler rather than Generac and he said that he sells Kohler as he does not like getting called out when the generators don't start, sounded like an honest answer. We are down at the end of a peninsula, the first to lose power and the last to get it restored!

Really appreciate the input, judging from the wuedtions and replies, looks like this was a good topic to bring up, esp here in the Northeast!

Happy Thanksgiving everyone!

Diesel, fuel oil, heating oil are pretty much the same thing. Here in PA heating oil is advertise with "Red Treatment for clean burn." In actuality, the red dye is to prevent a person from using it over the road since there isn't any road taxes on it. A DOT officer can place a device in a fuel tank and determine if with in the last month you ran heating oil and levy a steep fine on you. I've ran both in my tractor. Back to the point. We have both propane and diesel at work. The propane ones are  used on the smaller units even on the V-6 driven jobs. The one diesel that I know of is a 1M jobber used to run our Joy compressors to supply 30 psi air pressure for all our fementors.

Kohler gen sets have been dependable for us in some pretty remote places and friends have them in RVs and boats with equally good results. A neighbor in Borrego Springs has a, I think, 40KVA running on propane. Lots of power problems iut there due to lightning strikes during summer storms. I can't remember the % of load needed to keep regulation happy.

EdZ

You'll never have a problem with fuel oil as long as it's a 50/50 mix of kerosene. I lived at my camp for two years running my generator all night at times just to stay warm when it was 30 degrees below zero. Do not put a fuel filter at the output of the tank, put it in near the generator out of the direct atmosphere. If you put the filter at the bottom of the tank it will jell even with 50/50 mix. Just my experience, yours may differ.  

My first year staying at the camp was was a lesson in survival. It never went above zero for two months. Good ice fishing though ;D ;D ;D

One of the things Kohler brags about is their pure sine wave. I think they use what is called a 2/3 pitch winding that greatly reduces harmonics. Make sure it's a brush-less design with electronic regulation.    

The problems in the south are thunderstorms and ice storms. Lots of commercial and small industrial facilities are installing generators.

I am doing a project now with five 1.6MW/2.0 MVA 12.47 KV Cat diesels running in parallel for power generation to the grid. The  fuel source is very unusual. I can't talk much about it at this time.

Cotton?

Ask me in a few weeks. I can talk more about it then, but it's not cotton. It is a waste stream of mixed content. The conversion process is the secret.  If it works as it is suposed to - I wish I was a stockholder.

FWIW, the ONLY difference between #2 diesel fuel and #2 fuel oil is the dye and the road use tax! the dye is so the "proper authorities" can tell if you are running heating oil in a vehicle and not paying the road use tax. Also it is perfectly legal (at least in this state) to run #2 fuel oil (or heating oil if you must call it that) in bulldozers, pumps, welders, generators, earth moving equipment, etc because they are NOT being driven on the highway.

IMHO, the best choice for a fuel type should be what you have on hand. (whatever you heat with) Propane, natural gas or diesel, this way it is always on hand and you dont have to think about keeping your tank full. It is always there.

Gasoline is a poor choice for a STANDBY generator as it goes stale with time and usually causes fuel system damage in the process. (varnish) And you have to change your fuel every year as well as your engine oil.

Diesel fuel goes stale with time but still runs fine in the engine, it just changes color and smells peculiar.  I have a small tractor that is diesel that I dug out of mothballs this year after not being run for about 20 years. The fuel smells funky, more like Varnaleen than diesel fuel. It even has some of that black algae that grows in fuel oil in it. A fresh battery and about 10 revolutions of the engine and it came right to life and runs fine with the old fuel in it.

Patrick, I dont know if they are available in smaller sized units or not, yet. But for years they have used very large engines that run on both diesel and natural gas for natural gas line pumping engines. They use both the gas and diesel at the same time. They are compression-igintion (diesel) type engines that use a very small amount of fuel oil injected into the combustion chamber to light it off and a carburetor to meter in the natural gas to run the load. These are very large multi cylinder engines, large even in comparison to locomotive diesels. I have a friend that has a very specialized machine shop to rebuild them. This design has been around for decades.

My 2c ...

I do have one Kohler -- an 18 KW unit from about 12 years ago.  It is fine,  as it is an 1800 RPM LP-fueled job that is powered by a Ford in-line four and is water cooled.

The current generation of residential backup gensets are quite a lot less expensive than the old units like mine.  And, depending on the nature of your power failures,  the RES-14 will probably be fine.  These units run air-cooled engines,  and run at 3600 RPM.  They might not handle long-term power outages too well.

My application for generators is for battery charging in an off-grid hammie QTH.  This application is hard on gensets,  where Diesel units are preferred,  as the run-times can 5 or so hours at a fairly constant, heavy load.  My favorite genset is a Kubota 25 KVA Diesel which is very quiet,  and is switchable twix three-phase and split-phase (120/240 VAC).

But if your power outages are minutes to an hour or two,  a few times per year,  and you do not have constant,  heavy loads the RES units may well work fine,  and the price seems good.

YMMV and so on.  73  GL  Vic

If you paid for it, it's yours to use in anything you want, except to run vehicles on the highway, which requires fuels that were purchased subject to road tax. Farm tractors are exempt from the road tax for "occasional" use on highways, such as driving the tractor to a nearby work site.

A few years ago they started charging fuel tax for undyed kerosene used for heating (that doesn't gum up heaters), but you could request a refund on your IRS form.  Truckers were allegedly using kerosene and heating fuel instead of taxed diesel fuel on the highway, but that doesn't really make sense.  Kerosene (minus road tax) is still about $1.00/gallon more expensive than diesel fuel with tax included.

I think it's in VT that they actually sell "off road" #2.  I believe it's without the tax.

Don't farmers have to document what that fuel is used for or apply for a use permit?

I stopped at a rural station in Wisconsin once and found two diesel pumps with different prices SO naturally I started pumping the cheaper of the two. A few moments later the pump stopped... I went inside and the lady asked for my off road permit. Than she told me how much trouble I was in. She was kinda rude so I was looking over my shoulder as I left the county.

Mike

Yep, off-road is for use in anything that 'technically' isn't licensed for being on the road or in PA's case, has "FARM" tags. Kerosene is the samething being dipensed for the sole purpose of use as a heating fuel.
Slab Bacon pretty much answered my one question but left me standing with another. I have both propane and fuel oil here. If I were to go to propane, I would have to get a larger tank and pay the elevated 9/11 HAZMAT fee that goes with it. I could use fuel oil but I would have to probably install a secondary fuel pump to push the fuel from the basement up to grade where the gen-set would be sitting.  ???

I think a lift pump for the fuel oil would be a good idea Mike to make sure the supply was at the injection pump at the moment needed. A typical mechanical injection pump on the engine would probably do fine without a charge pump but the line might loose prime when not in use. A charge pump would help assure a quick start. Having the oil indoors at a warmer temperature might help it burn better during cold weather use. Sounds like a great start.

What is an "elevated 9/11 HAZMAT fee" all about?

Diesel is way more fuel-efficient than propane. Maybe makes twice as many KWH per gallon. With a 5 KW load, you'll use about 1/2 gallon of diesel per hour, at 10 KW around 1 gallon per hour.

Compare that to propane: A 10 KW generator with a 20 HP engine would consume about 200,000 BTU/hour. Propane contains about 90,000 BTU/gallon. That's at an assumed 100% engine efficiency, diesels are far more fuel efficient than gasoline or propane spark-ignition engines.

Commercial diesel back up generators have thermostatically controlled fuel heaters and some constantly circulate the tank's fuel through filters with a small pump. This can also be a lift pump.

In an emergency, you can run diesels on any vegetable oil from the supermarket- Canola, soy, Mazola corn oil, even warm (liquid) bacon grease. Kerosene is also a useful fuel in diesels. And you can use #2 heating oil or motor fuel. Rudolph Diesel made his first engines that ran on peanut oil, there wasn't a refined petroleum industry back then.

Downside is that #2 diesel fuel can have a limited storage life. It can support algae growth if even a small amount of water is present. You need to add a diesel biocide to the tank if it is stored for years.

The gasohol being sold in many states is nasty to carburetors. I have found it corrodes needle and float valves- eventually- if they're not drained before long-term storage. (Yes, I now know how to rebuild Briggs and Stratton carburetors- LOL). A gasoline additive is "Sta-Bil" which is supposed to preserve gasoline and prevent gumming. I use it in my own 7.5 KW standby Kohler.

Another option I've looked at is running an AC generator off the PTO of my diesel farm tractor. Not automatic, but cheaper than having to buy another engine along with the genset. The generator gets bolted to a pad, you back the tractor and PTO shaft up to the generator.

How about a wood-fired steam engine?

That's a good summary Bill.

Diesel has more than 40% more BTU content than Propane.  And  seems that the Diesel gensets have  much better fuel economy at lighter loads compared to gasoline/Propane fueled engines.  IIRC,  my Diesel genset burns 1.8 GHP at full load,  and 1.0 GPH at half load ... not a bad ratio.

Energy content table:
http://www.generatorjoe.net/html/energy.html

Here the grid power has become much less reliable,  so many,  many more folks are buying generators.   Seems kinna wasteful.

72  GL  Vic

FWIW, you can burn JET-A or JP-4 fuel in a standard diesel engine. A favorite trick in airport ground equipment. It's good down to extremely cold temps without any heating.

Well, then that solves that. It probably makes more sense since I have a larger supply of fuel oil VS. propane.

Mike asked:
Its about a $35 fee added to the cost of using a 100 lbs. propane tank. It has been replaced by 2-25lbs jobs. When I asked about it, the propane co. told me that after 9/11 they HAD to assess a HAZMAT fee on them. Personally I think its all hooey and just a way to make more deliveries to me.

Bill asked:
Probably because you don't want to turn your back on a steam boiler. I bet a neat little verticle steam turbine would work awesome but you would have to 'ride it' or have some fancy computer program to stay on top of it and I don't like the consequences if it gets away from a computer.

Bill said:
Yep. Pretty much nothing more than "polished" kerosene. If it gets into your water, you don't need any conditione when washing your hair. It makes it nice and soft. I remembered that when I had hair.  ;)

http://www.beamalarm.com/foretravel-links/PDF/Racor_300200_pre_fuel_filter-48027%20Rev%20B%20(OBSOLETE)%20Integrated%20Series.pdf (http://www.beamalarm.com/foretravel-links/PDF/Racor_300200_pre_fuel_filter-48027%20Rev%20B%20(OBSOLETE)%20Integrated%20Series.pdf)

Mike, This product might be perfect for your installation. Mounted close to the engine this will filter the fuel, separate water AND purge any air in the line. Air in a fuel line can cause the injector pump to cavitate and can ruin your day. Newer fuel injection systems use a much improved fuel delivery system and air isn't a big deal. Older technology mechanical fuel injection is the norm for gen sets and other stationary diesel engines. Air in a fuel line for mechanical diesel fuel injection means put the food in a snow bank and get out the blankets.  ::)  Some sort of check valve in the basement to keep the fuel in the line might be a good idea and extra care to make sure you have the fuel line sealed tight is just good practice.

I would pick the FR or MFR model. Scroll down for an installation schematic.

Mike

$35.00 per  "what" ?

I have a 300 gallon tank, and unless they have rolled the fee into the cost of fuel, they haven't charged me extra since 9/11

Or does this only apply to the little 100lb tanks?

I was hoping to find it on their website but it did apply to my 100lbs. tank. They wanted a real obnoxious price for it vs. 2 of the 25lbs cylinders. Like I said earlier, I think it was a way to charge me more for delivery rather than me buy in greater quantity at a lower rate.

Bill,
     Adding the diesel biocide is a good idea, but I really question it's necessity. My tractor is still running on diesel fuel that is somewhere close to 25 years old. It DOES have the black algae growing in it, but my dual fuel filters are keeping it out of the injection pump. The fuel has a very perculiar smell in the tank, but the exhaust smells like any normal diesel engine running on #2. And it starts just fine with it.

If you are using a diesel genset fueled off of your heating oil tank, that will never be a problem as the fuel will never set that long. The biggest problem using your heating oil tank is the sludge and debris that accumulates in the bottom of the tank. For some reason fuel oil seems to have a tremendous amount of gunk and debris mixed with it. You MUST have a good filtering system to keep it out of the injection pump.

Slab,

I wonder if the "gunk and debris mixed with it" is the algae itself?

Mike

A severe algae infection can result in a fuel tank full of "snot".   This snotty algae can plug filters.  But,  it is correct that the algae requires the presence of water.

Keeping the fuel tamk topped off helps reduce water infiltration.

I use a fairly heavy dose of the biocide in diesel fuel as insurance.

Vic

I used to buy red dye fuel for the utility tractor but I use so little mowing 5 acres and moving snow that it wasn't worth running 20 miles to the farm co-op to buy it.

The biggest gel problem now with diesel is the amount of bio (from Soy) that gets mixed in since it has a much higher gel point.  I assume they aren't doing that to home heating oil yet.

With modern HPCR (high pressure common rail) injection systems diesel lubricity is a major concern so I wouldn't want to try any of the jet fuel varieties without the manufacturers consent.  With home heating oil I would add one of the various lubricity enhancers just to be safe.  Although soy oil creates a problem with gelling it is a great lubricity enhancer.

I have only had one gelling experience in a pickup and that was enough.  It was in my '95 after I foolishly bought some diesel from a nearby station because it was convenient.  After running about 30 minutes in -24 (actual temp) conditions I stalled and had to change filters to make it to a store and add some anti-gel.  My current pickup has a heater in the fuel filter assembly but I still keep a spare and tools handy just in case.  With a generator you could easily put a wrap of heat tape around the filter since this is the choke/trouble spot from waxing/gelling.

The nicest part of having a generator is not having to sweat the ice storm forecasts!

OH yeah, the methanol at 10% is nasty against the boat engines around here, and there's huge stink in the works as Agri-business lobbyists try to get the feds to push it up to 15%.

Sta-Bil has worked pretty well for me in both the regular and high-test versions, used in the 1969 Datsun roadster and the 1964 Buick Electramobile that sit here for months without being out for a drive.

I just got a $20 bottle of the "marine" grade StaBil to handle the 40 gallon capacity of the boat now that it is put up for the winter. The reviews suggest it keeps the methanol/water content from separating, causing stratificaiton where the water sinks to the bottom right where the pickup pipe is.

Here on the west coast, it's the law.  The lead that comes OUT of your regulator on the tank is the EXACT SAME SIZE as the BBQ propane tanks.

I've kept my kids warm for 3-4 days at a time.  10 gallons a day, making a trip down the mountain every day.  For some reason, the 4 companies that service my area don't feel 4x4 trucks would pay off.  Of course, the owner of the largest lives at the TOP of the mountain, but he has FOUR propane tanks on his property :)

One xmas, we lost power AND had no propane.  I think that's the Christmas I'll forever remember, bar-b-queing hamburgers over our fireplace with my 4 and 5 year old......  It was a COLD and icy Christmas, but the memories will remain.

--Shane
KD6VXI

OH MY GHOD A REAL EXPERT! PLEASE HELP!  ;)


Now, here's my situation:

• 1700 Sq. Foot ranch house near Boston
• Natural Gas heat and hot water
• Electric pumps for heating system (Forced hot water)
• A couple of through-the-wall AC units, used only in summer
• An electric range for cooking
• Modest Ham Radio setup; roughly 2kw consumption
• No solar, battery, wind, water, or geothermal capability
• Power outages two to four times per heating season

Here's what I need to know, and would greatly appreciate your expertise on:

• What are the trade-offs between "Home Depot" generators and Kohler or other commercial-grade models? Would you recommend Coleman/Generac/etc. sets -
  
  • Never?
  • For emergency use?
  • As a reliable source for use two to four times per year?
• What about the mid-level generators like Honda? (My brother, W3TDH, swears by the Honda sets because the inverter produces "cleaner" AC). Is shopping in between "consumer" and "commercial" tiers a reasonable price/performance compromise?
• Is installing a diesel set worth the extra cost for a tank, lines, etc.?
• Are there options other than a backup generator? Can I get by with battery inverters or similar standby systems? Are they cost-effective compared with a generator?

Let me thank you in advance for your help.

73,

Bill, W1AC

AC  Bill,

Even if your outages last days,  batteeries/Inverters do NOT make sense.  The Kohler mentiond is a residential unit,  not really Commercial/industrial.  Residential units are probably fine for most home back-up uses,  unless the outages are extended,  and the power denands are high.

You might want to have a small porpane camp stove for cooking during outages,  as the electric stove is a large load.  A BBQ should also suffice.

Regarding small tanks and Propane (LP) gensets:  Usually LP generators are fed from Vapor.  The LP is evaporated at the tank.   In very cold WX or with a small tank,  the tank can freeze.  This chokes off the Propane supply.  Perhaps in the NE and other COLD climates,  the LP is fed as a liquid to the genset,  where there is an evaporator.   BUT,  usually these evaps are warmed by cooling water from a water cooled engine powering the genset.  There must be an electrically-heated evap for you folks in COLD climates,  as most reasonably sized gensets are now driven by air-cooled engines.   Here,  I have no experience.

It is COLD here in CA now --  Its 46 degrees outside!

YMMV   GL    Vic

Paul said:
Well, then you do what they do at work: You make a cut! Drain the water until you get past the "rag" or emulsification layer and voila......no more water. Just don't shake it up.

Funny you mention that, I recently had to get two different service guys out to fix a Kohler 80 KW liquid-feed propane generator. Powered by a turbocharged Ford 460 V8. The problem was that the speed would surge out of control when it first started, causing an automatic overspeed shutdown.

The first guy dinked with the electronics and governor and gave up.

The second guy figured out the problem- The engine's block heater had failed. The propane wouldn't gasify in a cold engine and just stayed liquid at what, -40F, into the engine. Just like flooding the carb on a gasoline job. Even when the ambient temperature was in the 70s or 80s, it flat wouldn't run properly.

So in reality, liquid propane generators need block and fuel heaters as much as diesels do. Maybe even more so.

We had originally bought a propane set because we felt they might be easier starting than diesels in extremely cold mountain locations, but it ain't so. Diesel or propane, your block heater better be functional.

The only other advantage to propane was that you don't need some sort of a containment structure as needed in the event of a leaking diesel or gasoline fuel tank.

Bill said:
The newer glow plugs only require a few seconds and you are fired up and back on line. I thought it was Ford that said they would come out and start your Power Stroke Diesel if it failed to light off.  :-\

Mike,
       It was just the trash that they failed to filter out of it. You could run some fresh #2 out of the tank truck into a cup and see minute traces of black junk at the bottom.
Part of it may just be sloppy handling of the product by the suppliers as they use the same tank trucks to haul and deliver other products like "bunker oil" and back haul used waste oil. I used to work for a company back in the 70s that did that. I was hired as the truck mechanic, but I wasnt going to crawl into every trailer and steam it out between loads. The #2 we hauled would "wash" the tanks clean for us.  ;D  :o

Personal Message (Offline)
   
   
Re: Home Generators - Kohler?
« Reply #38 on: Yesterday at 11:59:24 AM »
   Reply with quoteQuote
Quote from: N4LTA on November 24, 2010, 06:18:34 PM
I design quite a few large generator systems, and every now and then a small residential system.

OH MY GHOD A REAL EXPERT! PLEASE HELP!  Wink

Quote from: N4LTA on November 24, 2010, 06:18:34 PM
Kohler is a good generator and they make a good residential option. I have always considered them slightly behind Cat and Cummings but not far. They are way ahead of the Generac and similar generators.

Now, here's my situation:

    * 1700 Sq. Foot ranch house near Boston
    * Natural Gas heat and hot water
    * Electric pumps for heating system (Forced hot water)
    * A couple of through-the-wall AC units, used only in summer
    * An electric range for cooking
    * Modest Ham Radio setup; roughly 2kw consumption
    * No solar, battery, wind, water, or geothermal capability
    * Power outages two to four times per heating season


Here's what I need to know, and would greatly appreciate your expertise on:

    * What are the trade-offs between "Home Depot" generators and Kohler or other commercial-grade models? Would you recommend Coleman/Generac/etc. sets -
          o Never?
          o For emergency use?
          o As a reliable source for use two to four times per year?

The Kohler is a better set than the Home Depot specials.  They are more reliable and tend to start when you need them.  I myself have a Coleman that I use for offsite things and when an ice storm shuts off power. If you let it sit unused though, it will likely not start when you need it. Last time I needed it to loan to a friend - it would not start - cost $75 to get it repaired (gunk in carb)


    * What about the mid-level generators like Honda? (My brother, W3TDH, swears by the Honda sets because the inverter produces "cleaner" AC). Is shopping in between "consumer" and "commercial" tiers a reasonable price/performance compromise?

The small Hondas are very nice and quiet. I am not familiar with the larger ones - but Honda makes a very good engine. Commercial sets are very expensive (compared to home sets) and are usually three phase. Three phase  generators are a better option for waveform purity.

    * Is installing a diesel set worth the extra cost for a tank, lines, etc.?

Yes - if you want to run for long periods and have motor starting loads.


    * Are there options other than a backup generator? Can I get by with battery inverters or similar standby systems? Are they cost-effective compared with a generator?

Not if you have a load of any size and you need to have backup for periods longer than a few hours. We typically install an inverter system with a gen-set backup for seamless transfer with no momentary loss of power. We do this generally for data and computer installations.

Pat

Met with the electrician today, discussed the project.
Need to trench about 5 feet, run two cables in conduit out of the house to the generator, install the transfer switch inside, build a plywood panel to hang switch, change over wiring.

Does $1850 for the above work sound high?

Probably not. It sounds a little high to me - but lately  - everything sounds high to me. My son is a contractor and he just got a price for wiring a new garage from three electrical contractors. It was $7200 for the low bid - which sounds real high to me.

I am a licensed electrical contractor also and it makes me wonder if  engineering is the wrong business for me.

"  Does $1850 for the above work sound high? "

Is this just the labor, or does it also include the transfer switch/ cu/conduit etc?

klc

If that price includes the copper, that's a bargain, that's got to just be labor.
Although you could size up and use aluminum, even that's not cheap any more.
No way could the transfer switch be included.

Sorry, should have been clearer!

$1850 was for the electrical work, not the genset or xfer switch.

Interesting story today, had another electrician come over for a check, here is what he told me:

- 7,200 volts runs into my breaker box, I asked if he meant 240, he said no, 7,200 run from the meter to my breaker box

- The 200 amp breaker on my box protects the wire between the meter and the breaker box, not the panel and circuits after it, in fact we need to install another one to "protect" the power cable between the meter and the transfer switch

- That the resettable circuit breakers on my smaller manual generator transfer panel are "fuses", not circuit breakers

- They would have to install a sub-panel with a new set of breakers because the transfer switch is not designed to switch over the whole house, this despite Kohler clearly states and shows that in their design info

Needless to say that I called back electrician #1 and asked him to handle the job.

 " Interesting story today, had another electrician come over for a check, here is what he told me: "


                                                Thief



The dirtbag isn't stretching the truth, he's lying. Know any DA's??


klc

Thief, maybe, or just very ill-informed.
Either way it was amusing.

  " Thief, maybe, or just very ill-informed.  "

Having family & friends in the trades makes me very unforgiving..... 


klc

Funny thing is he told Nancy and I he had his Maine electricians license.
I sure hope that no one gets hurt.

Wow, the Maine electrician licensing exam must have been "dumbed down" by the same group that designed the FCC exams.  So we have extra class hams who can't build a HF dipole and an electrician who is unaware of the stepdown pole pig but believes in the magical breaker box genie that converts 7200 down to 240 volts.

Your generator project is certainly interesting and entertaining!

I'd run from that guy as fast as I can.

The electrical contractor license test is a standardized test and it is not easy - I am talking about the Masters test not the journeyman's test. It is not about theory but about the code for the most part. If you know the code book, then it's not too hard  - If not - you will be in trouble.

No way that you have any 12470/7200 volt equipment in your house or anyone else's house (unless is Ham equipment - a pole pig)

Labor rate around here is about $35 per hour for a burdened electrical worker on average.

So the quote that you have is for about a weeks work plus profit.  A couple of guys 2 1/2 days is probably right.