3000W Chinese Gensets Info.

[professor95]

professor95 wrote:
EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here.

In the eight year run of this thread we have amassed almost 10,000 postings and surpassed a million views. This creates somewhat of a dilemma for anyone who has just discovered the forum.

Since the amount of information is virtually overwhelming, I suggest you set your preferences for this thread to read "newest first" and then begin to page backwards.

What you will find in these pages is a wealth of info on virtually any make or model of Chinese manufactured synchronous (non-inverter) generator in the 3,000 watt performance class. Info will include how to rewire series coils to parallel to obtain maximum wattage from a single 120 volt outlet. Tips on further reducing sound levels, how to care for these generators, which ones are "RV ready" and provide the best overall performance for the dollar invested. Which companies NOT to deal with, where the best prices are, how to safely wire the generator into a home or RV, how to check your RV for electrical faults, sources for generator accessories, which 20/30 adapters are safe to use and which are not. How to convert a gasoline generator to propane or NG. This is only the beginning. The forum has a life of its own with the focus sub-topic switching frequently. Still, the main topic of utilizing the amazing, inexpensive Chinese gensets is always there. The amount of creativity and innovation presented in these pages is indicative of the talents shared in the diverse backgrounds of the folks who make up our combined RV community.

Many of the original brands and models of Chinese gensets mentioned in the introduction and early pages of the thread have since disappeared. New EPA and CARB emissions requirements, company bonds assuring the emissions warranty will be honored even if the company goes out of business, and fierce competition in the industry have changed the playing field. Champion Power Equipment has become the apparent "trophy team" providing an ever expanding retail outlet, an ample parts supply, a strong warranty and excellent customer service. CPE has continued to improve their product and now offers a new model (#46538) with exclusive convenience, safety and performance features aimed at the RV market. Big names like Cummins/Onan, Honda and Generac all now have Chinese built open frame synchronous gensets available. Ironically, the prices often found on these gensets has not significantly changed during the past eight years - even with the devaluation of the American Dollar and new EPA/CARB requirements.

I also encourage you to use the search function and even the advanced search options to find information. Key works such as "rewiring", "PowerPro", "Champion", "Onan Homesite", "Duropower", "ETQ", "Jiung Dong or JD", "Tractor Supply", "Costco", "Lowe's" and "Home Depot" are all examples of keywords that will give you specific information on different models being sold by retailers today.

Or, you can fill your glass with your favorite beverage (keep more close by - maybe some munchies as well :D, sit back at your computer, tell your wife (or significant other) that you will see her in the morning and spend the next 10 or so hours reading through the postings.

No one on the forum gets mad if you ask a question that is a repeat. Please do not hesitate to post to the forum. All questions are considered important and those active on the forum will do their best to respond with a valid answer.

Also note we are not out to knock the Honda, Yamaha, Kipor or other brands of high end digital gensets. We recognize the quality of these products and their suitability for quite, efficient RV use. But, there is a flood of reliable, inexpensive and comparatively lower cost gensets coming out of China that are excellent alternative choices for the RVer wanting power to run an air conditioner, microwave, etc. without excessive noise or breaking the budget.

Oh, one last thing. The folks on this forum are true gentlemen. We do not flame one another or the product discussed - period. Ugly contributors usually have their comments and remarks ignored by our masses. It is not a forum to start arguments to obtain a clear win. We do disagree on many issues, but we have all agreed to do that in a respectable manner.

We now have the introduction of more and more inverter gensets. There is a rather extensive thread named "The Official Unofficial Champion 2000i Generator" on this forum. Today, I added info on the new Champion 3100i inverter genset. Discussion on this product may get moved to its own thread at a later date.

Many have looked upon this thread with distain saying Chinese is cheap and doomed to failure. I remember saying exactly the same thing about Japanese products a few decades back. But, over the past eight years the track record for Chinese built generators has shown otherwise.

Please, join us in a fascinating journey down the Chinese built genset road of knowledge.

This is the question I posted that got it all started back in March 2005.......

Randy

For a little over a month now, I have been somewhat intrigued by the availability of a 3000 watt, 6.5 HP generator at Pep Boys and Northern Tool for under $300.00. The engine on this generator looks identical to a Honda 6.5 HP OHV engine. Knowing that the Chinese have become very adept at “cloning” reputable technologies from other manufacturers, I was not surprised at the similarities. Neither store could give me any information on the generator nor did they have a “running” display model.

I have done a little research. This is what I have discovered:

Many of these generators are imported by ELIM International (www.eliminternational.com) out of Buffalo, New York from Jiung Manufacturing in China. (The unit at Northern is identical but carries the JIUNG name.)

The engines are indeed a Chinese knockoff of the popular 6.5 HP 196cc Honda Engine. “Supposedly” Honda has licensed the engine technology to the Chinese manufacturer of the product.

The Chinese company that makes the ELM3000 generators is a rather large, diverse, long-standing company with a reputation for “above average quality” Chinese made products (Jiung Manufacturing). There are many more Chinese companies making almost identical gensets.

The generators at PepBoys do have a six month limited warranty. But, it is only on the engine (not the generator) and requires paying for shipping to and from Buffalo. Probably not a very practical thing to do if you have warranty issues.

ELIM does supply replacement parts (a PDF parts manual is available on the ELIM web site). No prices are given for replacement parts nor is there an “availability listing”.

The generator head itself is a brushless design. The only really significant wear parts in the generator are the bearings – most likely universally available.

The published dB rating is 67 at 23 feet. This is “reasonably” quite for a generator of this size as most comparabl.... The 67 dB rating is the same as Honda gives their 3000 watt CycloInverter with a “look alike” eng...

[professor95]

tvman44 wrote:

By breakout box you are referring to one of these transfer switches that connects as a sub-panel right?

No - sorry if that statement was confusing.

A "Break Out Box" as I referenced would be something you would make up from devices purchased from an electrical supply or home store like Lowe's. For example, a 30 amp TT male plug, a length of 10-3 SJ or SJO cord, a 4" square plastic or metal handi-box and two 20 amp duplex outlets that would provide four plug-ins for standard plugs on extension cords. This type of break out box would allow the highest amount of current the generator can provide (25 amps)for starting higher current 120 VAC devices.

[MrRchitty]

A transfer switch would disconnect all three wires from the street and connect all three wires from the generator to your panel. (I realize that you have four from the 240v plug, two hots, 1 common and 1 ground) If the common and ground bar are tied in your breaker box, mine use the same bus bar, then, yes, your generator's common (neutral) will no longer will be floating. I am not an electrician and have learned most of my stuff from a couple of co-workers who are electricians, however they can not tell me much about generators. That is where the professor comes in.

[bill_h]

mrekim wrote:


Yea that's why the 46514 is attractive. I'm sure that I can run the things I need in 220 mode, but I'm not positive that I can start them.

Yeah, me too. My 46514 connects to my 3/4 hp well pump right at the controller during outages. This short cord cuts voltage losses. I plug the pump into the 120/240 volt receptacle on the generator. I wait a minute for the generator to stabilize, and then open the yard hydrant (and maybe bleed off some pressure) so the pump starts against a minimal load, then flip the outlet selector switch to the 4 prong twist lock receptacle.

As soon as the pump is started, I shut off the yard hydrant and let the pump fill the tank/accumulator.

When that is done, I move the voltage switch on the gen to 120 to power the house. This uses a longer cord, but the current draw is low, so we are OK. During this time, the tank/accumulator supplies the house with water for quite a while.

If we run out of water before the power comes back on, I repeat the process. The house has no power while the tank/accumulator is being filled, but that is not long.

So far, so good.

[tvman44]

mrekim wrote:

professor95 wrote:

But, please keep in mind that if you were to try and use the unit with a transfer switch for home back-up in 220 mode you would have only 15 amps MAX for each of two branch circuits.

Yea that's why the 46514 is attractive. I'm sure that I can run the things I need in 220 mode, but I'm not positive that I can start them. I'm going to start with properly sized extension cords for emergency use and once I know what works, I can add a transfer switch.

professor95 wrote:

The 46514 is better suited for backup operation by connecting to a breakout box via the single 30 amp 120 VAC outlet or splitting the 220 volt outlet via a different style breakout box into two 15 amp circuits.

By breakout box you are referring to one of these transfer switches that connects as a sub-panel right?


I have one other question to ask. Hopefully it's relevant enough in this thread....

All the emergency items (sump, refrigerator, lights, etc.) can be powered by removing the plug from the wall and the device being powered is isolated from the house circuits. Since I'm going to hold off on the transfer switch for the time being, I needed to add a plug to my direct connected 120V heater blower motor. I added an outlet connection to enable this. On thing I noticed is that, even with the blower motor disconnected, there's still continuity on the round ground plug for the blower to the newly installed metal outlet box.
Even with a transfer switch the ground from the electrical system is still connected to everything in your house, in other words the transfer switch does not open the ground, just the hot wires
At first, this alarmed me. After thinking about it, I decided that the 220V AC unit was another source of ground for the blower unit since there's a metal connection between the two (copper coolant pipes).

This also means that when the generator is plugged in to the heater blower, its green wire ground is connected to the house wiring and therefore it's also bonded to the common wire via the main breaker panel.

Does this impact how the generator is configured when used for emergency backup and would it be different depending on whether it's connected to the blower motor?

[mrekim]

professor95 wrote:

But, please keep in mind that if you were to try and use the unit with a transfer switch for home back-up in 220 mode you would have only 15 amps MAX for each of two branch circuits.

Yea that's why the 46514 is attractive. I'm sure that I can run the things I need in 220 mode, but I'm not positive that I can start them. I'm going to start with properly sized extension cords for emergency use and once I know what works, I can add a transfer switch.

professor95 wrote:

The 46514 is better suited for backup operation by connecting to a breakout box via the single 30 amp 120 VAC outlet or splitting the 220 volt outlet via a different style breakout box into two 15 amp circuits.

By breakout box you are referring to one of these transfer switches that connects as a sub-panel right?


I have one other question to ask. Hopefully it's relevant enough in this thread....

All the emergency items (sump, refrigerator, lights, etc.) can be powered by removing the plug from the wall and the device being powered is isolated from the house circuits. Since I'm going to hold off on the transfer switch for the time being, I needed to add a plug to my direct connected 120V heater blower motor. I added an outlet connection to enable this. On thing I noticed is that, even with the blower motor disconnected, there's still continuity on the round ground plug for the blower to the newly installed metal outlet box.

At first, this alarmed me. After thinking about it, I decided that the 220V AC unit was another source of ground for the blower unit since there's a metal connection between the two (copper coolant pipes).

This also means that when the generator is plugged in to the heater blower, its green wire ground is connected to the house wiring and therefore it's also bonded to the common wire via the main breaker panel.

Does this impact how the generator is configured when used for emergency backup and would it be different depending on whether it's connected to the blower motor?

[MrRchitty]

bill h wrote:

MrRchitty wrote:
This allowed enough start power from the generator to start and run the well pump.

TThis thing bogs significantly for about 1/2 a second and once the pump is up and running, it is no longer an issue.

What size is your pump and how deep is the well?

I don't know what size the pump is, even though, at different times during my residence here, I've had it out. It runs on a 15 amp 220 volt circuit breaker. It's about 135 feet. However, the water level is about 10 feet down from the cap. So, it actually is not pumping against the height of the water, more so than the friction of the water flowing in the line.

If I am over explaining, I apologize, but water weighs a little less than 5 psi when in a column per 10 feet. It is a rough figure we use when pumping hose lines with a fire truck. We have to acommodate friction loss, required pressure at the nozzle tip and factor in elevation. We do 5 psi per 10 foot floor.

So, if my well has water in it and is about 10 feet from the top, the water pushes down on the pump and up the line to the current height. My pump therefore must overcome the 10 feet above water level and friction loss.

Edited for content, received an alarm during response to this post.

[bill_h]

MrRchitty wrote:
This allowed enough start power from the generator to start and run the well pump.

TThis thing bogs significantly for about 1/2 a second and once the pump is up and running, it is no longer an issue.

What size is your pump and how deep is the well?

[bill_h]

professor95 wrote:

The advertised level is 68 dB, but the true level will range from 65 to 74 depending on load and which side you are facing.

I got 72 dbA @ 7 meters with a (silent) resistance heater putting a 42% load on it on soft dusty dirt in a totally silent environment. Exhaust side, but since the muffler is pretty good, I wouldn't expect much difference from another direction. Most of the noise seems to be clatter.

Every other Champion I measured read either the same or louder, probably due to AC noise and reflection.

[MrRchitty]

Professor,

When using the 46514 in the 220volt mode and you build a box with two 15 amp circuits, each supplied by a seperate winding, I noticed in the wiring diagram of this generator on CPE's site that the AVR samples a portion of one of the windings. So... if you use one of the 15 amp circuits where the AVR is not sampling from, the voltage on the leg would fall when loaded. The other leg stays at or around 124 volts. If you use the other circuit where the AVR samples from the winding, the voltage on that leg stays at or around 124 volts when loaded, however, the unused leg voltage increases when there is no load on it.

I have read something about this, here in the recent past.

How to get 220 volts from a 120 volt Champion 3500 / 4000 Watt generator, model number 46515.

I have the 46515 which is a 120 volt only model with a 30 amp 3 prong along with the RV connector and a single 20 amp receptacle. During Irene, I took the cover off the generator head and removed the 4 wires coming from each of the windings. Originally, it was 2 blacks on the first nut and 2 dark reds on the second nut, thus parallel allowing me to get the full 3500 watts on the twist lock or RV connection. I removed the wires from the block and I metered each pair (dark red and black is one pair, and a dark red and black for the other pair) to determine which pair belonged to what winding... I reattached the wires to the wiring block in the following order 1 black on first nut, 1 dark red and 1 black on second nut and 1 dark red on the third nut. See my picture below.



The 14-2 romex was attached at the far ends of the block as pictured to give me 220 volts to the well pump.

Just before attaching the two wires to go to the panel on the generator for 120 volts, I did another test. As indicated above, I found that only one of the windings is sampled by the AVR. I attached the red and white wires as indicated by my picture to two of the nuts and put a small load on it and took voltage readings. This is where I saw the voltage fall off, but the other winding remained at 124 volts. I then switched the red and white going to the panel to the other two nuts and ran the same test. With the small load, the voltage to my generator panel remained at 124 volts, however, the other leg increased to 140 volts. This would give me use of the generator panel to supply 110 volts to small stuff, ie, 1 refridgerator, a couple of the mini flourescent lights, etc. This allowed enough start power from the generator to start and run the well pump.

This is where I say that if you want to know the absolute minimum sized generator you can buy to run a few things at home... if you have a 220 volt well pump, 3500/4000 generator is it. This thing bogs significantly for about 1/2 a second and once the pump is up and running, it is no longer an issue.

****Safety note: when metering the field wires from the generator, I did this with the generator off and used an Ohm meter. Preferably one that beeps when you have continuity. If you don't know what you are doing, please don't attempt. If you attempt to wire the red and white wires going to the panel to nuts 1 and 3 to get 220 volts to the panel, when you start the generator, the moment it sees about 160 volts it shuts off due to the overvoltage protection circuit. I am not going to admit that I was trying to get 220 volts to the panel on my generator and attempt to wire to my well pump with the 3 prong adapter and then leave this behind and hope my DW does not plug anything else into it... No.

[MrRchitty]

Professor95 wrote:
During our recent power outage from Isabel, I used my inverter generator to connect to my APC 1000 UPS, which is connected to my digital home entertainment (TV) system, because the UPS would not work with the signal from the synchronous generator. The UPS interpreted the "noise" and distortion of the synchronous unit as a power interruption.

Nice article. Did you mean "Irene" ?

[professor95]

mrekim wrote:

I might be willing to give up the 240VAC if there was good gain in AC signal quality.

The 46514 is one of the "main line" workhorse units for CPE in the 3000 watt class. There are thousands of them out there doing a great job.

The needs you listed do make it appear that the 46514 would do the job for you. But, please keep in mind that if you were to try and use the unit with a transfer switch for home back-up in 220 mode you would have only 15 amps MAX for each of two branch circuits. If a branch circuit of 15 amps, rather than the often needed 20, would power your equipment it might be OK. Professionally (as an EE and Master Electrician) I would not advise interfacing a 3500 to a residential SEP. The cost and power limitations are not compatible unless you have a small cabin in the woods. The 46514 is better suited for backup operation by connecting to a breakout box via the single 30 amp 120 VAC outlet or splitting the 220 volt outlet via a different style breakout box into two 15 amp circuits. As you know, there is only one 15 amp North American style outlet and circuit on the 46514 so using it exclusively only provides 1/2 of the available 120 VAC power.

Your parts listing was interesting. I have never taken the initiative to compare them as you did.

The 40008 I own and tested is now obsolete. UltraFab was the only distributor for this model. It was either the first or one of the first 120 VAC only models. When I first tested my 40008 my observation was that it had lower distortion than the models that switched the windings from series to parallel with a switch. In truth, my measurements of THD varied greatly depending not only on the apparent load but the power factor of the device being powered. The greater the load, the greater the distortion. The lower the PF% of the load device, the greater the distortion.

Actually, harmonic distortion of the AC sine wave from this class of generator rarely is an issue for RV and home appliances. At the higher THD levels some gas furnace controls and UPS systems rejected their signal. Certain brands of microwave ovens also developed less power and "cheap" non-ballast fluorescent shop lights flickered at higher THD. Other than that, refrigerators, pumps, TV sets, fans, and lights operated without problems.

During our recent power outage from Isabel, I used my inverter generator to connect to my APC 1000 UPS, which is connected to my digital home entertainment (TV) system, because the UPS would not work with the signal from the synchronous generator. The UPS interpreted the "noise" and distortion of the synchronous unit as a power interruption.

The world of Chinese synchronous generators is complex and well populated. Earlier, I encountered some models with really cheaply made alternators and regulators. I now believe the majority of those are no longer marketed in the USA. The EPA pretty much did away with the cheap models when it implemented the $5 million emissions performance bond a couple of years ago. I am now under the impression that most all of the available Chinese synchronous generators in the 3,000 watt class are pretty much the same as far as the quality of the AC signal.

All of the 3,000 watt class Chinese synchronous generators are going to have pretty much the same exhaust and mechanical noise level unless they have some sort of sound canceling added. The advertised level is 68 dB, but the true level will range from 65 to 74 depending on load and which side you are facing.

[mrekim]

professor95 wrote:


CPE is giving THD numbers higher than what I have measured on my unit. Interesting - it usually works the other way.

I might be willing to give up the 240VAC if there was good gain in AC signal quality.

I was able to find a thread where you tested a 4008 and found the waveform to be quite good. Have you tested other models? I looked and did not see anything other than the 4008 waveform and some examples of other mfg (I think) waveforms.


I'm looking at the 46514. If that machine is known to be noisy (or has any other issues) I'll go for another - even just 120V if I have to.

At this point, I don't need elec start so I don't want to pay up for that unless I'm getting something else and the elec start is just an "extra".

Given that the only units that have the load delay/shedding are the remote start ones, and that feature only applies when using the remote, I'm willing to forgo it and come up with another means of ensuring the generator is not started or shut off while load is applied.

I was hoping to gleen something from the parts listings between to 4008 and the 46514. It looks like an older 4008 and the 46514 are close, but I don't know what that -2.5 suffix is on the stator assy. I'm guessing that the new 4008 parts numbers are related to the load delay/shedding since most of the other 3500/4000KW units seem to still have the "old" part numbers.


4008 - Elec Start, 120V, 3500/4000W
New #................Old#................Desc
ST168FD-120-0004.....ST168FD-1152031.....AVR
ST168FD-120-0001.....ST02FD-1152035......Brush Assembly
ST168FD-120-0008.....ST02FD-1152020......Stator Assembly
ST168F-2-100-0001G...ST168F-2-1000000G...6.5 HP Generator Engine

46514 - Pull Start, 120/240V, 120 Only switch, 3500/4000W
ST168FD-1152031.......AVR
ST02FD-1152035........Brush Assembly
ST02FD-1152020-2.5....Stator Assembly
ST168FD-2-01000000G...Engine

46515 Pull Start, 120V, 3500/4000W
ST168FD-1152031.......AVR
ST02FD-1152035........Brush Assembly
ST02FD-1152020-2.5....Stator Assembly
ST168FD-2-01000000G...Engine

I added this since you referenced it and thought it would be interesting to see if any parts crossed over.
46538 Elect Start(remote) 120V, 3000/3500W
AVRO2-00000000.........AVR
ST02FD-02100009........Brush Assembly
ST02FD-02120000-2.5....Stator Assembly
ST168FDE-2-GC2.........Engine

professor95 wrote:

Why do you need 240 VAC? About the only item you can use it for in the USA is a small (1/2HP) shallow well pump. If that is your goal and the noise level is not of greater issue the new 41533 is a a 46538 on steroids. It has a 50 amp RV plug and all the safety features. It makes a great home back up unit when coupled with a transfer switch.

A home backup with transfer switch is the goal. I could probably do what I need with 120V but there wold be less work more flexibility with 220.

41533 is too big for me. I can run my essentials: sump(700W), gas heat blower(875W) and refrigerator(65W) on the 3.5K unit.

[professor95]

mrekim wrote:


Is there any way to tell which models have the load delay/shedding and/or the Volt Guard?

I'm looking for a 120/240 unit in the 3500 watt range (rated) with a 120/240 switch and haven't been able to see from the manual or parts list any reference to Volt Guard.

I also recall reading that some units have a better THD rating than others. Is there some place where I can look this up?

To the best of my knowledge, Champion is the only Chinese manufacturer including the volt guard in their synchronous generators. An aftermarket volt guard unit named the "KillAVolt" is available from SuperGen Products. It plugs into one of the 120 volt outlets and provides over voltage protection for all outlets. You also keep access to the outlet used since the KillAVolt has a pass thru socket. I have one and they do work.

Again, to the best of my knowledge, the CPE46538 with remote electric start is the only Chinese synchronous genny with the load activation delay and load shed before shut down. Ironically, the features of the 46538 were the direct result of what was unanimously asked for by folks that frequented this forum thread. Without our input I doubt it would have ever been offered.

CPE is giving THD numbers higher than what I have measured on my unit. Interesting - it usually works the other way.

Why do you need 240 VAC? About the only item you can use it for in the USA is a small (1/2HP) shallow well pump. If that is your goal and the noise level is not of greater issue the new 41533 is a a 46538 on steroids. It has a 50 amp RV plug and all the safety features. It makes a great home back up unit when coupled with a transfer switch.

Yes, the CPE42412 is a "brush-less" unit - also known as a short shunt self exciting field generator. I know of no one that has worn out a brush set on an AVR equipped generator. But, I do keep a set in my spare parts box - just in case. IMHO, the 42512 is an amazing little workhorse of a genny.

[mrekim]

professor95 wrote:

Shutting down with a load of course causes a voltage drop. As voltage drops current will rise (remember watts = volts x amps) and the AVR does it's best to compensate by increasing voltage/current to the armature. This can cause heating in the P/N junction of the bi-polar transistors of the comparator circuit which "may" lead to failure.

Running generators of this type does involve risks. This is why CPE designed the newest synchronous generator with load delay/shedding circuitry which helps to keep this from happening. Also why they have added the Volt Guard to some models.

Is there any way to tell which models have the load delay/shedding and/or the Volt Guard?

I'm looking for a 120/240 unit in the 3500 watt range (rated) with a 120/240 switch and haven't been able to see from the manual or parts list any reference to Volt Guard.

I also recall reading that some units have a better THD rating than others. Is there some place where I can look this up?

Champion's response to the THD question was:

Our open frame synchronous generators have approximately 4% THD below 25% load. At 80% load, THD increases to about 11-13%.

I got some Volt Guard info from Champion.

Every Champion Power Equipment brush style generator produced after October of 2010 ships with our Voltguard technology. You can determine the manufacturing date of any Champion generator by the first digits of the serial number with correspond to year and month of manufacture.

Our 1200W generators are brushless.

More info from Champion with respect to load delay/shedding:

Our remote start units have this feature. It is tied to the remote signal. If you start the generator from the electric start or from the recoil, this feature is NOT activated.

[professor95]

eljefino wrote:


So here's a question that I didn't see answered in the first 170 pages I read, what is the purported advantage of AVR? If my load suddenly lessens, the engine speeds up... if it cuts alternator load to keep from over-volting what's left, that only causes the engine to speed up even faster. Is that the point? To get the governor to correct the engine speed faster? A more precise feedback loop?

Capacitors are frequently used in short shunt self exciting Chinese synchronous generators for one major reason - they are cheap!

Unfortunately, the capacitor used as a regulator can allow for wide swings in voltage for different loads. They also depend upon a diode across the capacitor going into avalanche about half way through a rising or falling AC cycle to "clip" the field current. This dip is often interpreted by the load device as a change in voltage polarity (zero crossing detectors) that can make performance erratic. For example, clocks may run at 2x speed in microwave ovens and some older ferro-resonate converter/chargers will not function. We will also find a significantly higher level of harmonic distortion of the AC sine wave in capacitor regulated synchronous gnerators.

That said, most every appliance in an RV - with the exception of some microwave ovens and really old converter/chargers, operate safely and functionally from a capacitor regulated generator.

The AVR, or Automatic Voltage Regulator, provides a more precise voltage regulation by quickly varying the voltage to the exciter winding as load changes. It is somewhat independent of engine speed. AVR controlled generators also show less THD and appear to operate microwave ovens in RVs with fewer problems.

None of this applies to "inverter" generators which create their own waveform and regulation from 3 phase alternators with totally electronic control modules.