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I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups - EconomyMode=Off. -- PeteCresswell
"(PeteCresswell)" wrote in message
I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
No, it's just that a certain amount of fuel is required to keep the motor turning at 3600 rpm.
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups - EconomyMode=Off. -- PeteCresswell
Somewhat more load dependent. Some fuel is required to keep it turning at the no-load rpms, which is around 2800 rpm.
(PeteCresswell) wrote:
I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups - EconomyMode=Off.
I used to drive truck over the road. I looked into the Honda EU generators. The runtime was not sufficient to my needs, plus, the regulations and other government BS would have been problematic in carrying extra gasoline on my diesel powered truck.
What I liked about the design, I ended up using for myself. The honda makes its juice with an automotive style alternator / rectifier and uses an inverter to make it into AC. As the other reply to your post points out, with an AC power head, the shaft has to spin at a certain RPM even under no load. The Honda throttles up according to the actual mechanical power demand required by the alternator. It loafs at idle with low power draw.
That concept offered a solution to my problem, albeit not near as quiet. I already had a 750 watt inverter on the truck.
I purchased a Yanmar one cylinder air cooled diesel engine, 3.6hp IIRC; A 130 amp 12 volt heavy duty truck alternator; some pulleys and a V-belt; an aluminum box; and some angle iron to mount it to the truck frame. Approx. $2500 total.
I sold the truck before I could fully tweak the system, but even so, the unit had about 1/3 paid for itself in a year.
In looking at alternator power output vs. RPM and calculating actual RPM mounted on the truck's main motor, I opted for a 1:2 pulley system, spinning the alternator at double the motor RPM. In hindsight, I think I would have got more power out with a 1:1 setup. The motor stalled at 100 amps, (I had it load tested) but did put out 80 amps without too much trouble. I could shut down the main motor at temps down to zero F. I used a 12VDC 300 watt electric heater and a 120 VAC electric blanket.
Compare: Less than a gallon in 24 hours v. 48 gallons in 48 hours idling the road motor at the required 1200 rpm.
But I digress.
"(PeteCresswell)" wrote in message
I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
NO! The inverter generaters (in "Eco" mode) have a fuel burn that is much more linear with load than a conventional generator. Normal generators have to run a 3600 rpm regardless of load, so the pumping losses and cooling losses are much the same regardless of load, but an inverter generator can run slowly with a low load, greatly minimizing those losses.
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups -
Still very good economy compared to anything you can buy at Home Depot. Did you try it with the Eco mode "On"?
Vaughn
"soundhaspriority" wrote in message
"(PeteCresswell)" wrote in message I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
A typical generator WILL use more fuel depending upon the load. For example, a 5000 watt generator that uses 1 gallon per hour with maximum load would probably use about one fourth that with no load. This may vary greatly depending upon the quality of the engine etc.
No, it's just that a certain amount of fuel is required to keep the motor turning at 3600 rpm.
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups - EconomyMode=Off. -- PeteCresswell
An eu2000 will run (according to Honda) about 15 hours with no load. I have ran mine for about 12 hours or more on a tank of gas with a small load. It will run about 4 hours with one half load.
Somewhat more load dependent. Some fuel is required to keep it turning at the no-load rpms, which is around 2800 rpm.
No, it's not. It's probably more in the neighborhood of around 600-800 rpms.
"Ulysses" wrote in message
"soundhaspriority" wrote in message
"(PeteCresswell)" wrote in message I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
A typical generator WILL use more fuel depending upon the load. For example, a 5000 watt generator that uses 1 gallon per hour with maximum load would probably use about one fourth that with no load. This may vary greatly depending upon the quality of the engine etc.
No, it's just that a certain amount of fuel is required to keep the motor turning at 3600 rpm.
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups - EconomyMode=Off. -- PeteCresswell
An eu2000 will run (according to Honda) about 15 hours with no load. I have ran mine for about 12 hours or more on a tank of gas with a small load. It will run about 4 hours with one half load.
Somewhat more load dependent. Some fuel is required to keep it turning at the no-load rpms, which is around 2800 rpm.
No, it's not. It's probably more in the neighborhood of around 600-800 rpms.
Wrong. 2800 rpm.
Per Vaughn Simon:
Still very good economy compared to anything you can buy at Home Depot. Did you try it with the Eco mode "On"?
I don't know much about generators.... but based on the frequency with which my neighbor has to fill his 5kw generator's tank I'd agree.
What I'm doing now is three things: --------------------------------------------------------------------- 1) Familiarizing myself with the device's capabilities,
2) Getting through the 20-hour break-in period so I won't wind up needing to do an oil change in the middle of a winter night sometime, and
3) Figuring out how much gasoline I should budget for what period of time under a given load. ---------------------------------------------------------------------
I haven't run a full tank in Eco mode yet. I'm hung up on worrying about the fridge - which cannot start itself the first time in Eco mode. Freezer starts itself ok, but the fridge needs 3-5 attempts and I don't know whether this is stressing the fridge/gennie or not.
Understood that I could turn Eco mode off for the fridge to start - but eventually it's thermostat is going to turn it off and it will have to re-start unattended at some later time. It's an old one, but I'd still hate to fry it and have to buy another.
Maybe somebody who knows can resolve this for me: will repeated unsuccessful attempts to start damage a refrigerator? How about the gennie? -- PeteCresswell
In article , "(PeteCresswell)" wrote:
unattended at some later time. It's an old one, but I'd still hate to fry it and have to buy another.
Well, you might find that a new one costs less to run (on or off generator). The Rule of Thumb (irritating to us holders-onto-of-old-stuff-that-still-works) is that a fridge beyond about 7 years of age is costing you enough more to run that a new fridge will pay for itself (if you choose an efficient new fridge, of course). And that's on-grid - when you're paying for generator fuel, the savings will pile up even faster.
-- Cats, coffee, chocolate...vices to live by
"(PeteCresswell)" wrote:
Per Vaughn Simon:
Still very good economy compared to anything you can buy at Home Depot. Did you try it with the Eco mode "On"?
I don't know much about generators.... but based on the frequency with which my neighbor has to fill his 5kw generator's tank I'd agree.
What I'm doing now is three things: --------------------------------------------------------------------- 1) Familiarizing myself with the device's capabilities,
2) Getting through the 20-hour break-in period so I won't wind up needing to do an oil change in the middle of a winter night sometime, and
3) Figuring out how much gasoline I should budget for what period of time under a given load. ---------------------------------------------------------------------
I haven't run a full tank in Eco mode yet. I'm hung up on worrying about the fridge - which cannot start itself the first time in Eco mode. Freezer starts itself ok, but the fridge needs 3-5 attempts and I don't know whether this is stressing the fridge/gennie or not.
Understood that I could turn Eco mode off for the fridge to start - but eventually it's thermostat is going to turn it off and it will have to re-start unattended at some later time. It's an old one, but I'd still hate to fry it and have to buy another.
Maybe somebody who knows can resolve this for me: will repeated unsuccessful attempts to start damage a refrigerator? How about the gennie? -- PeteCresswell You should consider a new fridge if your old one is more than 7 years
old!!! My eu1000 starts my fridge in econo mode even with my freezer and furnace allready running.
"(PeteCresswell)" wrote in message
Per Vaughn Simon:
What I'm doing now is three things: --------------------------------------------------------------------- 1) Familiarizing myself with the device's capabilities,
Good
2) Getting through the 20-hour break-in period so I won't wind up needing to do an oil change in the middle of a winter night sometime, and
Whoa! Oil change periods aren't THAT rigid! A few hours one way or the other won't hurt a thing, just make sure that they really happen.
3) Figuring out how much gasoline I should budget for what period of time under a given load.
A supposedly obvious step that few people seem to think about.
---------------------------------------------------------------------
I haven't run a full tank in Eco mode yet. I'm hung up on worrying about the fridge - which cannot start itself the first time in Eco mode. Freezer starts itself ok, but the fridge needs 3-5 attempts and I don't know whether this is stressing the fridge/gennie or not.
My big (old) 'fridge starts easily in eco mode with my EU2000i, and it also starts fine with a 1000-watt Yamaha inverter generator in the eco mode. You might consider a new box, or it is possible for an AC technician to add a "hard start" kit to your present unit that should eliminate the problem.
You can also manually "play games" with the thermistat to make cycling less of a problem. Simply turn the thermistat on max cold and let the thing run continuously for an hour or so, and then unplug it for an hour or so.
Maybe somebody who knows can resolve this for me: will repeated unsuccessful attempts to start damage a refrigerator? How about the gennie?
The answer to both questions is "possibly yes". Your concern is well placed.
Vaughn
-- PeteCresswell
Per Vaughn Simon:
it is possible for an AC technician to add a "hard start" kit to your present unit that should eliminate the problem.
I'd probably opt for the replacement fridge - maybe a used one, which sb pretty cheap.... but what would the kit consist of? -- PeteCresswell
"(PeteCresswell)" wrote in message
Per Vaughn Simon: it is possible for an AC technician to add a "hard start" kit to your present unit that should eliminate the problem.
I'd probably opt for the replacement fridge - maybe a used one, which sb pretty cheap.... but what would the kit consist of?
There are purpose-built "hard-start" kits that consist of a module that you connect across the compressor's capacitor. A cheaper solution that is sometimes sufficient is to simply install a larger capacitor (or parallel the existing one). Manufacturers tend to save pennies by installing the smallest starting capacitors possible, and they don't improve with age.
You can use the same technique on small window units to reduce the starting surge to accommodate a small generator. I just did one last weekend, but unfortunately I have the part number at my shop. I hope to run that 8500 BTU AC with my EU, but haven't tried it yet.
Vaughn
-- PeteCresswell
"Vaughn Simon" wrote in message
"(PeteCresswell)" wrote in message Per Vaughn Simon: it is possible for an AC technician to add a "hard start" kit to your present unit that should eliminate the problem.
I'd probably opt for the replacement fridge - maybe a used one, which sb pretty cheap.... but what would the kit consist of?
There are purpose-built "hard-start" kits that consist of a module that you connect across the compressor's capacitor. A cheaper solution that is sometimes sufficient is to simply install a larger capacitor (or parallel the existing one). Manufacturers tend to save pennies by installing the smallest starting capacitors possible, and they don't improve with age.
You can use the same technique on small window units to reduce the starting surge to accommodate a small generator. I just did one last weekend, but unfortunately I have the part number at my shop. I hope to run that 8500 BTU AC with my EU, but haven't tried it yet.
Vaughn
-- PeteCresswell
Sorry but I did not read the original post, but here is some information that might help.
Not sure what a "Hard-Start kit is, but some air conditioning units/refrigeration units have a relay that has closed contacts when not energised, and open when energised, these contacts switch in a capacitor to help start compressor.
This relay is energised a second or so after the power is sent to the compressor, so it this 'start' capacitor is only connected momentarily. IE it helps to start the compressor, but then is shut off.
One system that had a 240 AC volt power supply, this relay had a coil voltage of 320 AC volts.
The start capacitor varies with the size of the compressor, and with a 2 HP 240 volt compressor I have seen a 165 mf capacitor used, while the run capacitor was 35 mf.
As for this helping to start a compressor on a limited power supply such as an invertor or small generator, I cannot see how this will help, as the capacitors need to charge up at the same time as the compressor is drawing maximum current, thus actually increasing (momentarily) the current needed but there again, I have never tried it, so I do not know.
My limited experience on this says more current drawn from the too small generator/invertor means even more lower voltage, of course if the unit is being fed from the mains, then this is not a problem, as there is plenty of power to set things in motion.
----------------
As for just fitting a larger capacitor to the existing unit, well depending if the existing capacitor is of the 'start' or 'run' type, if only a start capacitor, then a moderate increase could help, but if it is a 'run' type then you would be increasing the overall power usage of the compressor, and therefore could be putting the compressor at risk of burning out.
I had a problem with my pool pump (1/2 Hp 240 volt) not starting recently and had the 12 Mf capacitor (run) checked at a local electric motor rewind shop, it was down to 9 Mf, a new one has since fixed the problem
Be interested to see how you go with this.
Run capacitor is connected permanently across the windings. Start Capacitor is only connected for a brief time while the compressor starts, and is shut off by a relay, after starting. Some units have both start and run capacitors fitted.
"RamRod Sword of Baal" <RamRod @truthonly> wrote in message
Sorry but I did not read the original post, but here is some information that might help.
No offense, but is doesn't.
Not sure what a "Hard-Start kit is,
Then why are you giving advise?
but some air conditioning units/refrigeration units have a relay that has closed contacts when not energised, and open when energised, these contacts switch in a capacitor to help start compressor.
Yes, a true "Hard start kit" contains a relay inside the module.
As for this helping to start a compressor on a limited power supply such as an invertor or small generator, I cannot see...
Yes, we can see that...
how this will help, as the capacitors need to charge up at the same time as the compressor is drawing maximum current, thus actually increasing (momentarily) the current needed but there again
The capacitor does not "charge" in the way that you are imagining. Think of it as a reactive device that is acting against the Xl of one motor winding to cause a phase shift. If there is insufficient capacitance, there will be insufficient phase shift which will cause insufficient starting torque which will cause a very high start current.
I have never tried it, so I do not know.
Again no offense, but that is obvious.
My limited experience on this says more...
I know, and no disrespect intended, but that is why I have to say these things so that no one takes your advise on this particular matter.
Vaughn
"Robert Morein" wrote in message
"Ulysses" wrote in message
"soundhaspriority" wrote in message
"(PeteCresswell)" wrote in message I keep hearing references to a generator "dumping" excess capacity.
Does this mean that generator can be expected to use the same amount of fuel whether unloaded or loaded to the max?
A typical generator WILL use more fuel depending upon the load. For example, a 5000 watt generator that uses 1 gallon per hour with maximum load would probably use about one fourth that with no load. This may vary greatly depending upon the quality of the engine etc.
No, it's just that a certain amount of fuel is required to keep the motor turning at 3600 rpm.
Is the situation different for inverter-bases generators? I've got an EU 2000, which just ran 5.7 hours on a tank running a fridge and a freezer (235 and 350 watts respectively), about 600 watts total exclusive of startups - EconomyMode=Off. -- PeteCresswell
An eu2000 will run (according to Honda) about 15 hours with no load. I have ran mine for about 12 hours or more on a tank of gas with a small load. It will run about 4 hours with one half load.
Somewhat more load dependent. Some fuel is required to keep it turning at the no-load rpms, which is around 2800 rpm.
No, it's not. It's probably more in the neighborhood of around 600-800 rpms.
Wrong. 2800 rpm.
If it's running at 2800 rpm at idle then what is it running at when at full load? 5000 rpms? It's obviously running a LOT faster at full load. >
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