Picked up a HF Predator 3500 Inverter Generator

[Bluejoe]

Our shop has had plenty of all makes and models of generators in to maintenance or repairs. On the engine side most owners don’t maintain proper maintenance. It doesn’t matter what brand. If you get other than Honda change out the plug for NGK. Change oil regularly, clean air filter. Most are foam. Briggs motors have paper element. Run good treated fuel. Don’t allow it to run rich or it will build up carbon on piston head and valves. The smaller non Honda ones the electronics goes before the engine.

 

[bpjr]

A little searching finds the predator engines are used by many cart and lawn tractor racers with great reliability and success. This goes back yrs and is one reason I bought a 2" HF dewatering pump with the 212cc predator. It has 50-60 hrs wide open throttle pumping about 9k gals an hr in 6 yrs. It ran 30 hrs straight last time a hurricane came through and starts 1st or 2nd time when pulled out of storage once a yr for hurricane prep. Other than oil changes no problems. Same deal with my Northern Tool 4k generator with 212cc engine that appears to be identical to the predator. This gen ran 24x7 for 2+ weeks without a problem. It was stopped only for gas and oil changes. Zero issues with these engines. I have $750 total in both units and for occasional use my money would be wasted on Hondas.

 

[theoldwizard1]

I'm skeptical. How come inverter generators sell way cheaper than a quality inverter alone? Ever price a good 3000W inverter? Seems like there might be some corners getting cut.

Starting over 5 years ago, I started researching inverters. There are basically two different type and an inverter generator is a very close cousin of the first.

Type I (my nomenclature)
1) Convert the DC to AC (square wave, typically over 40 kHz) and feed it to one or more small transformers. A pulse width modulate controller is used to maintain the proper output voltage of this stage.
2) Convert the high voltage (about 300V) to DC.
3) Generate a low voltage 60 Hz sine wave (many different methods)
4) Feed the sine wave and the high voltage DC into an amplifier (typically a Class D) and, with some filtering and feedback, you have 120V 60 Hz AC

Type II (my nomenclature)
1) Generate a low voltage 60 Hz sine wave
2) Feed the sine wave and the low voltage DC into an amplifier (typically a Class B or Class D)
3) The amplifier feeds a LARGE/HEAVY transformer and you have 120V 60Hz

Type II tend to be more expensive because copper is expensive and so are large fero-magnetic core.

An inverter generator works like a Type I, except the first 2 step are not required. The output of the stator is already about 300V and likely is 3 phase (much more efficient).

Also, modern (past 10-15 years?) designs, combine step 3 and 4 into one inexpensive IC ! Yes, there is some additional microprocessor "feedback" required to adjust the throttle based on the load. It does not take many years before every Chinese company has copied the "best" design and can sell it for less money (genuine single cylinder Honda engines versus "clone" Honda engines).

Older designed, which are still being sold use many discrete devices and BJT instead of FET drive transistor which waste power in the form of heat.


Also, fuses on the low voltage/input side are a waste of time and money. Fuses take 100s of milliseconds to act. Transistor blow in microseconds.

 

[mike93lx]

Starting over 5 years ago, I started researching inverters. There are basically two different type and an inverter generator is a very close cousin of the first.

Type I (my nomenclature)
1) Convert the DC to AC (square wave, typically over 40 kHz) and feed it to one or more small transformers. A pulse width modulate controller is used to maintain the proper output voltage of this stage.
2) Convert the high voltage (about 300V) to DC.
3) Generate a low voltage 60 Hz sine wave (many different methods)
4) Feed the sine wave and the high voltage DC into an amplifier (typically a Class D) and, with some filtering and feedback, you have 120V 60 Hz AC

Type II (my nomenclature)
1) Generate a low voltage 60 Hz sine wave
2) Feed the sine wave and the low voltage DC into an amplifier (typically a Class B or Class D)
3) The amplifier feeds a LARGE/HEAVY transformer and you have 120V 60Hz

Type II tend to be more expensive because copper is expensive and so are large fero-magnetic core.

An inverter generator works like a Type I, except the first 2 step are not required. The output of the stator is already about 300V and likely is 3 phase (much more efficient).

Also, modern (past 10-15 years?) designs, combine step 3 and 4 into one inexpensive IC ! Yes, there is some additional microprocessor "feedback" required to adjust the throttle based on the load. It does not take many years before every Chinese company has copied the "best" design and can sell it for less money (genuine single cylinder Honda engines versus "clone" Honda engines).

Older designed, which are still being sold use many discrete devices and BJT instead of FET drive transistor which waste power in the form of heat.


Also, fuses on the low voltage/input side are a waste of time and money. Fuses take 100s of milliseconds to act. Transistor blow in microseconds.

Very interesting background

 

[guy48065]

Starting over 5 years ago, I started researching inverters...

Thank you for the detailed response.

These inverter gennys are complicated. I don't see how generating AC, rectify to DC, chop into HF square wave, convert to LF sine wave is more reliable and efficient than simply spinning some coils near magnets to generate a "natural" sine wave. I believe they exist because they're cheaper to build than old-school stator generators--not because they do anything better or longer.

 

[mark-NJ]

Thank you for the detailed response.

These inverter gennys are complicated. I don't see how generating AC, rectify to DC, chop into HF square wave, convert to LF sine wave is more reliable and efficient than simply spinning some coils near magnets to generate a "natural" sine wave. I believe they exist because they're cheaper to build than old-school stator generators--not because they do anything better or longer.

Here's why:

To simply "spin the can to make a sine wave" is simple.

But making a constant 60Hz sine wave requires a constant-RPM on the engine, so speed control of the engine MUST be held constant, irrespective of changes in the electrical load. Engine control like that is very hard & requires expensive engineering & componentry, which these cheepie units don't have. Lacking these controls makes a power output that will vary in frequency, and that's bad...so they go the inverter route. The inverter's resultant waveform *****, but at least it's consistent.

(I'm in the power generation business)

 

[Rc_Guy]

I think 250hrs is alot more time than alot of these generators will see. Either way metal flakes in the oil is bad news. This is why i wont buy a generator that dosnt have a oil filter...unless its cheap enough.

Alot of reviews are like un boxing videos. They open the box and start the thing up...5 STARS.

My $4000.00 Honda 6500 does not have a oil filter, should I get rid of it?

 

[mark-NJ]

No, but be sure to change the oil every 100 hours...

That's the #1 secret to these small generators lasting: change the oil!

I think 250hrs is alot more time than alot of these generators will see.

Is it? I'm not inclined to agree...

- If it's being used on a jobsite for 8-hour workdays, that's 1 month.

- If it's being used to keep a house (partially) lit during an outage, that's 10 days. (During Sandy, I was out for 2 weeks...)

 

[Radix2]

Here's why:

To simply "spin the can to make a sine wave" is simple.

But making a constant 60Hz sine wave requires a constant-RPM on the engine, so speed control of the engine MUST be held constant, irrespective of changes in the electrical load. Engine control like that is very hard & requires expensive engineering & componentry, which these cheepie units don't have. Lacking these controls makes a power output that will vary in frequency, and that's bad...so they go the inverter route. The inverter's resultant waveform *****, but at least it's consistent.

(I'm in the power generation business)

You've kinda glided right past the main benefit of inverter generators.

Most gens operate at a fraction of their rated load - the inverter can slow the engine and match the load resulting in quieter efficient operation. The non-inverter must stay at the noisy frantic 3600RPM speed all the time. The inverter still needs good or better throttle control to match power - which is trickier than the flywheel governor 3600rpm gens use.

You hit on the way it works, just sorta missed the value of that independence of speed that the inverters give...

 

[kctyphoon]

No, but be sure to change the oil every 100 hours...

That's the #1 secret to these small generators lasting: change the oil!



Is it? I'm not inclined to agree...

- If it's being used on a jobsite for 8-hour workdays, that's 1 month.

- If it's being used to keep a house (partially) lit during an outage, that's 10 days. (During Sandy, I was out for 2 weeks...)

And aside from sandy - when’s the last time that happened?. Its been what, 7 years? Have you lost power since? I haven’t for more than few minutes - if that..

 

[mark-NJ]

You've kinda glided right past the main benefit of inverter generators.

We're going to have to agree to disagree. IMO (discard as you see fit), I don't see the IGBT's chopped output waveform as a 'benefit' at all.

And aside from sandy - when’s the last time that happened?. Its been what, 7 years? Have you lost power since? I haven’t for more than few minutes - if that..

Very true; You have a fair point. I think the longest outage we've had since then was about 6 hours when a truck took down a pole. Besides, the gen under discussion isn't meant for home standby at all anyway, so my original point was off target.

Still, I don't feel like 250 hours isn't all that much. If you take it camping regularly, or maybe use it on a jobsite or some such, I think 250 hours could pass before you realize it.

Either way, the key to longevity on ANY of these little units (and most small residential units, too) is change the oil regularly!

 

[andypress]

For what it's worth.....Consumer Reports scored it very highly in their testing (86/100, only two points behind the Honda eu3000is) and called it a "Best Buy".

Delivered enough wattage to power our test appliances and handled very surges well. Provided especially clean power with consistently high voltage. Especially quiet from a distance of 23 feet, especially pleasing to neighbors if you'll run the generator overnight. Easy to start and transport, with some helpful features for starting and operating the generator.

 

[kctyphoon]

I think I've started and used my big generator ONCE since I've bought it. It's sits around just wasting space .

 

[crucible]

Now, if they come out of a 240v capable inverter generator.......

 

[mike93lx]

Now, if they come out of a 240v capable inverter generator.......

briggs and stratton makes/brands one that's pretty attractively priced: https://www.homedepot.com/p/Briggs-...h-Briggs-and-Stratton-Engine-030675/301871650

 

[crucible]

briggs and stratton makes/brands one that's pretty attractively priced: https://www.homedepot.com/p/Briggs-...h-Briggs-and-Stratton-Engine-030675/301871650

Thanks Mike-I appreciate it, but I was really inferring HF here (and a potential Honda-esque clone) and wasn't clear about that.

Edit: I was looking at that B&S and pulled up another inverter gen, the Champion https://www.homedepot.com/p/Champion-Power-Equipment-DH-Series-6-250-Watt-Gasoline-Powered-Recoil-Start-Open-Frame-Inverter-Generator-with-301-cc-Engine-100519/308252910

Open frame, but claims a 69dba running sound level.

I sure do like seeing more and more inverter options at higher wattage ratings!

 

[guy48065]

...
But making a constant 60Hz sine wave requires a constant-RPM on the engine, so speed control of the engine MUST be held constant...

(I'm in the power generation business)

Then you're the right guy to answer this: What NEEDS precise and stable mains frequency? My AC synchronous clock and belt-drive turntable might run at a slightly wrong speed but I can't think of anything else where it matters much. All my electronics have DC power supplies, all my appliances are rated 50/60Hz (non-critical).

 

[Hiball]

Then you're the right guy to answer this: What NEEDS precise and stable mains frequency? My AC synchronous clock and belt-drive turntable might run at a slightly wrong speed but I can't think of anything else where it matters much. All my electronics have DC power supplies, all my appliances are rated 50/60Hz (non-critical).

The circuit board in today’s Newer heating cooling systems tend to dislike unstable power, it was a $500 dollar lesson for a coworker.

 

[garandman]

Thanks Mike-I appreciate it, but I was really inferring HF here (and a potential Honda-esque clone) and wasn't clear about that.

Edit: I was looking at that B&S and pulled up another inverter gen, the Champion https://www.homedepot.com/p/Champion-Power-Equipment-DH-Series-6-250-Watt-Gasoline-Powered-Recoil-Start-Open-Frame-Inverter-Generator-with-301-cc-Engine-100519/308252910

After Hurricane Sandy I did a risk assessment. Boston seldom loses power, and we have gas heat, stove and clothes drier. But if we got a storm like Sandy, or even more likely a winter Northeaster with heavy snow, because we live near the harbor we’d be subject to flooding and other problems. So I had the house wired with a transfer switch. Almost everyone affected by Sandy ran out of fuel at some point, so we wanted an inverter, along with greatly increasing the amount of fuel we stored.

We bought the B&S Q6500. Honda and Yamaha also make large inverters with 240V, but they are much more expensive and much heavier. The 128 lb Q6500 has Manual start, but is easy to store and move. The Yamaha EF6300 is $4,000 and 200 lbs dry. The fuel injected Honda EU7000 is $4,500 and 260 lbs.

Thought I posted a video on YouTube comparing it to a Honda EU2000i. They are both much quieter than conventional generators. We ran it for five hours and it used considerably less fuel than Spec.

 

[theoldwizard1]

These inverter gennys are complicated. I don't see how generating AC, rectify to DC, chop into HF square wave, convert to LF sine wave is more reliable and efficient than simply spinning some coils near magnets to generate a "natural" sine wave. I believe they exist because they're cheaper to build than old-school stator generators--not because they do anything better or longer.

The main reason they exist, is that portable generators see a wide range of loads. With all of that "fancy electronics" the engine can be throttled down for less noise and more importantly less fuel.

Most of the old fashioned, "natural" sine wave generator relied strictly on engine speed (mechanical governor) to control output voltage and frequency. Change the load, the engine would bog momentarily and you would have a wild swing in voltage and frequency. Not the best for some items !

As for "durability", the electronics have proved themselves.


Segue - While I do have a background in electronics, I have been retired for over 10 years. I have a "sickness" where I will "deep dive" a topic until I have a thorough understanding of it. I have not settled the "sickness" when it comes to IPTV !

 

[theoldwizard1]

Now, if they come out of a 240v capable inverter generator.......

Honda has one. $$$$ !

Easy, make 240VAC as I previously described and run it into a 240V - 240V/120V split transformer.

 

[theoldwizard1]

After Hurricane Sandy I did a risk assessment. Boston seldom loses power, and we have gas heat, stove and clothes drier. But if we got a storm like Sandy, or even more likely a winter Northeaster with heavy snow, because we live near the harbor we’d be subject to flooding and other problems.

IMHO, if you have no 240V appliances (including well pump and sump pump) with careful "management" of your loads, the average house could easily run on a 3000W (peak) generator, probably less. If you lived in the South, you could even run 1 small window A/C and keep a bedroom cool.

 

[theoldwizard1]

The circuit board in today’s Newer heating cooling systems tend to dislike unstable power, it was a $500 dollar lesson for a coworker.

I have heard the same thing and I don't understand why ? There are a couple of AC motors that don't care that much about voltage and frequency. The controls are all DC, so unless they are using really crappy AC to DC power supplies it should not be an issue.

(Most modern AC to DC power supplies are designed to operate from 100VAC to 250VAC and from 50Hz to 60Hz, +/- 10%)

 

[crucible]

Really? The EU2000i won’t run the AC in most zrV’s and the EU3000iS is pretty heavy.

The dial tone for RV AC: https://www.yamahamotorsports.com/generator/models/ef2400ishc

I'm not an RV'er, but I've had this one for the better part of eight years now, with little real use (bought after a week's worth of no power, of course it hasn't really been needed).

It can run needed utility loads and a small window a/c unit (or my previous home's gas furnace) quietly and efficiently, but you'll pay for it of course. (I have a duel fuel propane kit I haven't gotten around to installing, and have a marine gas tank waiting around to make a gravity extended fuel tank....eventually.) Had I been shopping now for similar capability, I'd likely get the Predator.

My new house has 240v well pump and other water treatment loadings; the most inexpensive thing likely is getting a smaller 240v generator and hardwire it to a load center for the water pump and treatment loads and keeping the 2400ishc for the rest.

 

[theoldwizard1]

My new house has 240v well pump and other water treatment loadings;

Depending on the HP of that equipment, you can try wiring a 240-120 transformer backward (yes, that is safe) ...

OR

... buy a 12VDC to 240VAC inverter. The "rest of the world" use 240VAC and 50Hz so these are common (I am sure you can buy an inverter generator that would make 240VAC @ 60Hz), and I am pretty certain that 50Hz vs 60Hz will not damage a typical AC motor, especially on a pump that only see a few minutes of usage every once in awhile.

 

[crucible]

Honda has one. $$$$ !

Easy, make 240VAC as I previously described and run it into a 240V - 240V/120V split transformer.

Yeap, only winning the lottery will get me one of those larger Honda's or Yamaha's! I suppose I can equally dream about a whole house backup generator while I'm at it-in for a penny, in for a pound.

 

[crucible]

Depending on the HP of that equipment, you can try wiring a 240-120 transformer backward (yes, that is safe) ...

OR

... buy a 12VDC to 240VAC inverter. The "rest of the world" use 240VAC and 50Hz so these are common (I am sure you can buy an inverter generator that would make 240VAC @ 60Hz), and I am pretty certain that 50Hz vs 60Hz will not damage a typical AC motor, especially on a pump that only see a few minutes of usage every once in awhile.

Thanks. As much as I like this stuff myself (I work in data center facilities-power, comm, etc.), I have to go a much easier route for my wife and daughters at home case I'm not around and work around's like this can't and won't be worked by them.

You may be on to something though re the "rest of the world" and 240v inverter generators!

 

[Rc_Guy]

My Honda 6500 inverter has 240v plug.

 

[guy48065]

I have heard the same thing and I don't understand why ? There are a couple of AC motors that don't care that much about voltage and frequency. The controls are all DC, so unless they are using really crappy AC to DC power supplies it should not be an issue.

(Most modern AC to DC power supplies are designed to operate from 100VAC to 250VAC and from 50Hz to 60Hz, +/- 10%)

You're an analytical man who's avoided the KoolAid table.

I've also heard that example of how "unclean" AC power can damage sensitive electronics. ONLY that one example and I'm wondering if it's urban legend to sell new generators (another "format change" every few years--sound familiar?), or if newer high-tech HVAC controls are really that crappy that they can't tolerate anything but a pure & smooth sinewave.

It would be far cheaper to wire in a filter to that furnace power and keep your current generator.

 

[thool]

For the past couple power outages, we simply cycled our generator. It's a Troy-Bilt around 6500 watts and it powers 6 15-A circuits via a manual transfer box. We run it for an hour to get the house warm, get the power vent gas water heater happy, keep the fridges rocking cold, and getting the sump pump low. After it cools off, it goes in the garage overnight. IIRC, I got up at 6am after the last outage and got the house squared away again within an hour.

Besides being heavy even on wheels, the only other hassle is trying to keep enough fresh E0 gas on hand. I strive for 10 gallons, treated with Stabil, rotated every few months.

Reminds me: I have to put together a laminated usage guide for my wife, so if there is an outage and I'm away, she'll know what to do and not do!

 

[Alpine4x4]

Ran mine for the first time this weekend to start break in. Ran for one hour and changed oil as recommended on a few of the RV forums. Oil had metal shaving as to be expected. I didnt load it up too hard, draw was only 6-8 amps max. Couldnt tell when appliances were added or subtracted, it ran just as smooth and quiet unloaded as loaded with that small of a load. Will be swapping the plug to NGK just as a preventative measure. It will go to work Thursday night and run all weekend powering our camper and on-board boat battery charger.

 

[garandman]

Thank you for the detailed response.

These inverter gennys are complicated. I don't see how generating AC, rectify to DC, chop into HF square wave, convert to LF sine wave is more reliable and efficient than simply spinning some coils near magnets to generate a "natural" sine wave. I believe they exist because they're cheaper to build than old-school stator generators--not because they do anything better or longer.

Construction generators run at 3,600 rpm all the time to generate the proper voltage. They typically use a lot more fuel.

Inverters can generate 120/240 regardless of engine speed. They can use much less fuel at low Load. No benefit, and maybe a disadvantage at full load, but for variable loads they use less fuel.

They cost substantially more. Horses for courses.

https://powerequipment.honda.com/generators/models/eu3000is

https://powerequipment.honda.com/generators/models/eb3000c

 

[Bretny]

No, but be sure to change the oil every 100 hours...

That's the #1 secret to these small generators lasting: change the oil!



Is it? I'm not inclined to agree...

- If it's being used on a jobsite for 8-hour workdays, that's 1 month.

- If it's being used to keep a house (partially) lit during an outage, that's 10 days. (During Sandy, I was out for 2 weeks...)

No ones talking about a job site generator, only home backup. Also not many people are going to hsve the gas even for a inverter generator to run 2 weeks. Of corse Sandy was a freak event, but it could happen again.

Most all of the generators i see forsale that have a hour meter have well under 200hrs. I think alot of people buy them for an outage then stuff them back in the shed, in a few years they sell them.

 

[X1 Mike]

I bought a Predator in early March and have used it for a total of 4 race weekends so far. I race Hare Scrambles in Florida and the pits/campsite is generally in a cow pasture so I have 4 weekends where the generator has run non stop from Friday night till Sunday afternoon. Not the biggest sample size but not a single hiccup so far.


Somebody get me some Kool-Aid.

 

[Rc_Guy]

No ones talking about a job site generator, only home backup. Also not many people are going to hsve the gas even for a inverter generator to run 2 weeks. Of corse Sandy was a freak event, but it could happen again.

Most all of the generators i see forsale that have a hour meter have well under 200hrs. I think alot of people buy them for an outage then stuff them back in the shed, in a few years they sell them.

I looked at my quiet Honda 6500 yesterday, I have 2096 hours on it.

 

[Xpectation]

I have both 2 each Champion 2000 watt inverter generators (the ones that can stack on top of each other at the 4 corners) 73536i - I think I paid $399 each. I bought them in 2012 or 2013, and have right around 2000 hours on each one. (close guess). Each has seen 8-10 hours a day for several weeks at a time and never failed. Oil consumption is "not bad" - I think I add oil about every 25-30 hours or so.
Surge capacity stinks in "eco" mode. They just do NOT throttle up fast at all, and the "overload" trips way, way, way too easily. I always thought they were pretty good for what they are.... but, "they ain't NO Honda!!!"

I hate having to leave them at "full speed" but sometimes I have no choice - because they just won't "come up out of ECO mode" very easily.

I have one Honda eu2000i... I had two, but one got stolen.

I also have 2 each Predator 2000 inverters. They are currently running 8-10 hours a day, 5-6 days a week. Oil consumption is nil. They start easily and parallel together easily. They also will parallel easily with any other inverter generator that I have tried (Champion, Sportsman, Black Max, Honda and other Predators).
These are as close to a Honda as you can get. Noise level is *almost* as good, fuel consumption is maybe a little better, and "surge capacity" is excellent. I think I paid $439 each with a coupon back in February. Each one already has over 1000 hours on them. Oil gets changed about every 2-3 weeks (depends on weather) and about 150 hours. They can be a little cold-blooded for the first ten minutes.
BUT - when warmed up and running, they "come up out of ECO mode" very easily when a big load hits - they will even run some pretty big A/C units (it might take a second or two of struggling before they get there, but they don't "overload" at the drop of a hat, either)

There are some other very good Chinese inverter generators (the white Pulsar ones come to mind) and Costco has a "Yamaha powered" generic one for about $489 (?) or so.

A lot of this is anecdotal, but take it for what it is worth.