generator auto-idle control?

[Jagmandave]

I've got a 7k (12K surge) Generac with a B&S motor and it has this idle back feature. I use it a lot out at my "country" place where I have no electricity............I used it for my Mig welder with no problems, although I wasn't trying to do production welding, just fix the odd broken whatever. Anyway, it worked fine. I also have an electric pole saw that I used with it, again no problems.

 

[Mike_Lipke]

I view this feature as a bonus. You can switch it off or on. My car has cruise control, but I don't always use it, but happy I have it when I want to use it.

My genset has it and it works like a charm for hand tools and such. Saves tons of gas. Generators use a lot of gas.

When I use it for my well pump, both the pump and genset have a hard time spooling up:The pump because there is not volts and amps instantly, the genset because there is such a huge load all at once, it has a hard time revving up fast enough.

I like having it, even though I don't use it all the time. Can't see a downside to it.

 

[CurlyDave]

How does the auto idle control work? I'll assume if there is no load to the generator it idles down, and when a load is requested, it runs to standard RPM's...

I have a 15 KW (22.5 KW Surge)Generac which has this feature. When the load drops the generator idles down to a much lower RPM, and when a load is started, it takes a few seconds to come up to speed, sometimes emitting a cloud of black smoke.

I don't know about your lightbulb question, as I use it to power a 3 hp well pump.

I got the generator from Home Depot on line for $1800, which was the best price I could find. It was $2000, but I google searched for "Home Depot coupon" and found a $200 coupon. Delivery was free, and I consider it a really good deal.

A big plus for this generator is that it has a real spin-on oil filter, and it should last for a long time with regular oil changes. I got two filters with the generator, and took a new one to a car parts place to find a match so I can now get them locally and cheap.

The minus to one this size is fuel consumption, 1.5 gal/hour at load, maybe half that when idled.

I only need it for about 1/2 hour per day to fill the pressure tank, so that is not a big issue in my case, but running one continuously could add up to a lot of gas.

It is claimed to weigh 450 lbs dry, probably pushes 550 lbs with fuel and oil. Advantage: two high school kids with a pickup aren't going to steal it. Disadvantage, even though it comes with a wheel kit, it is hard to move. I never installed the wheels, just move it with a chain & my FEL -- it does have a lifting eye.

Overall, I don't think you can get more power for less money, and the only thing it lacks is an hour meter. I would buy one again in a heartbeat.

 

[Doc_Bob]

I have a 15 KW (22.5 KW Surge)Generac which has this feature. When the load drops the generator idles down to a much lower RPM, and when a load is started, it takes a few seconds to come up to speed, sometimes emitting a cloud of black smoke.

.

So this feature is simlar to what Honda has on their EU series where the speed of the generator varies depending on the load?
Bob

 

[Highbeam]

It doesn't sound to be equal to the Honda in operation. The description sounds like a light switch where it is full speed or idle with nothing in between. The puff of black smoke being the inability of the engine to consume the fuel load of full throttle as demanded by the governor trying to get the engine up to 3600 RPM ASAP.

The light switch calls for 3600 RPM with any load. Is that right dave? All or nothing? It would be much cheaper to make a genset that way.

 

[CurlyDave]

Is that right dave? All or nothing? It would be much cheaper to make a genset that way.

I think you are right. When there is no load, the RPMs drop, when there is a load the RPMs ramp up to the right value for 60 cycles.

I don't know for sure, but I have a hard time imagining a more sophisticated control system for that price.

The problem I had is that the 3 hp well pump requires about 8 KW worth of generator to start up properly, and this was actually the cheapest one available with a higher rating. I was very impressed with the quality for that price.

Just for comparison, the inverter-type Honda runs about $2000 for a 2 KW model, and about $1000 for the 1 KW version.

 

[HomeBrew2]

... Just for comparison, the inverter-type Honda runs about $2000 for a 2 KW model, and about $1000 for the 1 KW version.

Maybe you mean the 3+KW and 2KW with those prices. My 2000i was $1000 a few yrs ago ... I just found one quick listing for $1100 at CampingWorld.

 

[Steve_Miller]

Honda "EU" generators are the inverter type which generate DC and convert it to a true AC sine wave at 60 hertz. They have circuitry that senses the load and revs the motor to match the load, therefore only using as much power as needed and are one of the most efficient in the market. The drawback is that they usually don't have as much surge capacity as the AC generators. The inverter type generators usually have a switch that will load match or run full speed. The regular generators spin a generator head that has to run at full speed (3600rpm) to produce 60 hertz. The auto idle feature is as a previous poster explained, if there is no load present the motor drops back to a predetermined speed to conserve on fuel. Depending on the type of generator head (brush type or brushless), will determine the idle speed. This has to do with the surge capacity of that particular head. The brushless type cannot idle down as far as the brush type as they will not recover from a large load and will stall or sit there and spit and sputter.
Another thing that I have yet to find out is how the surge rating is applied to a generator. Maybe someone can chime in here and shed some light on the subject. Surge means what? a predetermined load for a certain period of time? Example: A 1500w gen with a 2100W surge. How long can the generator provide this 2100W? 2seconds 20 seconds? My 3500W Porter cable has a 7500W surge rating, I can't believe that it would be capable of 7500W for more than a few seconds. Another thing to watch for is the rating of the generator, some brands advertise for example a 6500W generator, but in the small print it is 6500W surge, 5500W continuous. Others advertise on the continuous rating.

I've babbled enough.
Steve

 

[Doc_Bob]

Honda "EU" generators are the inverter type which generate DC and convert it to a true AC sine wave at 60 hertz. They have circuitry that senses the load and revs the motor to match the load, therefore only using as much power as needed and are one of the most efficient in the market. The drawback is that they usually don't have as much surge capacity as the AC generators. I've babbled enough

Steve

Steve, please babble some more! How much capacity can you get in an inverter type generator? Matching the load to fuel consumption sounds very wise indeed.
Bob

 

[Steve_Miller]

Check out Honda's newest line, the EM series are 120/240volt inverter type.

Generators.<1>.

Steve