Generac plus Yamaha

For my toy hauler, I have a 96W solar array that maintains(barely)my 2 Trojan 105s during the day if I don't use anything more than my laptop powered by a 300W inverter.

I recently ordered a Yamaha EF2000iS generator to take the load off and charge the 105s during the evening/night so I don't bother my neighbors running my Generac 4500W Primepact 50LP and also save on propane.

The Generac 12V output is rated at 45A and I have seen it charging at 30+ amps when the batteries are low. The Magnetek 7300 inverter input is rated at 120V 775W, which is ~6.5A. The Yamaha AC output is: Rated 13.3, Maximum 16.7 amps @ 120V, so it should charge the batteries the same.

The Yamaha will be connected to my shore cable. What would happen if I fired up the Generac at the same time the Yamaha was running. My friend with a motor home has a Honda 2000 and says if he needs to, he starts his motor home generator with the Honda running without any problems. Wouldn't that be the same as being plugged in at an RV park and starting the generator? Is there some automatic switch to handle this?

Thanks,

It's Just Me.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha

    The Honda euX000i family is designed to share the AC output between two gensets (plug two eu2000i together on the AC output and start one, then the start the second, and they will share the output load).

    I don't believe that any other genset is designed to do this--so you will just end up popping circuit breakers (or worse) if you try to share outputs with any other genset.

    I would guess that you can share a single eu2000i with another source (generator or shore power)--but it is not recommended and probably not safe.

    If you are talking about running a genset to power the converter and another genset to power the rest of the AC loads--that can be done--but the AC circuits/loads need to be separate (can probably share a common neutral bond/ground).

    Otherwise, I am not quite sure what you are asking to do? There are AC transfer switches (manual and automatic) where the AC loads are switched from AC main to AC genset if mains fail. But you cannot "share" the AC power with two AC sources (other than with the Honda euX000i family).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    The Yamaha has: TwinTech™ capability - Hook up two EF2000iS’s for 3600 watts of maximum power.

    What I'm asking is if I have the Yamaha hooked up to my shore power cable and start the genset, would there be a problem?

    Same as if I was hooked up to shore power and started my genset.
  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha
    Just Me wrote: »
    The Yamaha has: TwinTech™ capability - Hook up two EF2000iS’s for 3600 watts of maximum power.
    Yes, you are correct--I forgot Yamaha had some models with this capability too.
    What I'm asking is if I have the Yamaha hooked up to my shore power cable and start the genset, would there be a problem?
    Depending on the AC loads--you may want to start the generator(s) first and warm up a bit before connecting/turning on the loads. A cold generator may stall if hit with heavy loads while coming up to speed. And if the load is large enough to require two gensets in parallel--you would have to start both before turning on/connecting the heavy load (if that is what you are asking).
    Same as if I was hooked up to shore power and started my genset.

    That is the statement/question I don't understand. Do you want to run shore power and the genset(s) at the same time? Power separate or the same load (i.e., share shore power + Yamaha share genset(s) to power one AC load)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Right now, I could go out and connect my trailer shore power cable to my house AC with an extension cord AND start my Generac genset with no problem.

    Would that be any different than having the Yamaha hooked up to my shore power cable and starting my built in Generac genset.

    Not talking about loads. Would there be a phase problem?
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    Re: Generac plus Yamaha

    Just to make sure but you suggesting instead of plugging the shore power lead in to the grid or an outlet you want to plug in to the generator and the Generac is built in to the trailer?

    If so that’s no problem. The trailer will only use one source of power, either the internal generator, in your case the generac, or the external power from the grid or your external yahama genset. It likely has a built in transfer switch and if the grid or shore power is present it will just use that and ignore the genset.

    Do you have a built in battery charger that comes on automatically when connected to shore power? If so that will run from the shore power plugged in to the Yamaha genset but keep in mind this is another load on the 2000w genset.

    Also if you have larger loads the 2000w will likely only run one at a time and to start larger loads you may have to turn off the quiet mode or variable speed option so the load has full power upon motor startup, you may be able to switch back once the load is running assuming it won't cycle on and off.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Got it figured out. I have nothing to gain by running the Generac and the Yamaha at the same time. The shore power plug has to be plugged into the trailer receptacle for the Generac to do anything AC wise. It does charge a max of 2A DC when not plugged in.

    So, if I was running the Yamaha and wanted to run the AC unit, it wouldn't pull the load. I would have to disconnect the Yamaha and plug the shore power plug into the receptacle.

    I don't know what my friends motor home has, but I'm pretty sure he said if he needed to run more than the Honda could handle, he would fire up his Onan genset. I'll have to ask him again. I'm almost sure there would be a phase problem it they were both connected to the same load. That's why I started this thread.

    I know the Yamaha and Honda both have special cords to run in parallel. Must be something the way the cords connect with banana connectors to match the phase.

    Thanks for the replies. I shoulda tested this first, but trusted what my friend said.

    The reason for getting the Yamaha is to charge my batteries with the built-in inverter quietly and without using propane.
  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha

    In general, you cannot connect various AC sources (generators, inverters, AC mains) together without lots of fireworks.

    There are some special cases:
    1. Some inverters have special cables/modes where they can phase syncronize
    2. Some small gensets (some Honda/Yamaha for example) have the ability to share the loads between two gensets of identical models.
    The Honda (and probably the Yamaha too) have a special power sharing mode inside their Inverter sections. The cabling is not "special" other than they add an extra circuit breaker to protect the load/genset pairs. The sharing circuitry is internal to the genset design.

    You can probably share one Honda or One Yamaha "power sharing model" with a standard genset (start the Honda/Yamaha second). However, I am not sure how well they will share (wrong voltage set points and possible frequency stability issues with non-inverter Main Genset).

    And there are safety issues. The "paired" gensets are the same rated output current. If you have one large genset and one small genset, it is possible to over load the wiring on the smaller genset and cause a fire/failure.

    The above two reasons are why I would not bother to try and power share between your Internal Propane Genset and your Yamaha power sharing model--but you are correct--Power sharing may actually work to some degree with the Yamaha/Honda genset+RV genset.

    Otherwise, just plug the load / shore plug into your Yamaha and use the gasoline instead.

    Probably the above is just as clear as mud. This is just my guesses based on my engineering experience--not with actual testing of any discussed units.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    I'm not even going to try to make a cord to run them both. Don't want to smoke the Yammie or have fireworks.

    Talked to my friend. He has some type of automatic switch where he doesn't have to plug the shore plug into a receptacle like I do.

    Thanks for the replied, just curious about what he told me.
  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha

    That sounds like an automatic transfer switch...

    In the simplest form, that is just a DPDT relay. The AC Mains powers the relay. This connects the loads to the AC Mains. When the AC Mains fail, the relay opens and connects the genset output to the AC loads instead (or the opposite).

    You can read about one model here.
    The ITS-30R is sometimes used as a ‘lock-out’ switch to prevent specific loads from being operated from designated supplies. Example: preventing a battery charger or air conditioner from running from an inverter, yet operating from generator or powercord.

    Of course, there are manual transfer switches and very sophisticated automatic transfer switches (generator warm up / cool down / weekly cycling / etc.). Lots to choose from.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Another friend had an older motor home that he had to manually switch it from AC to genset.

    That transfer switch would be perfect, except I don't have room in my shore cable compartment to mount it, and it would be too hard to wire the trailer to put it inside. Thanks for the link.

    I'll look for some manual ones and maybe even build my own from ckt breakers or check what HD has.

    From another forum:

    Square D part # QO2DTI Transfer Switch, about 8 bucks at the supply house. And yes, it is break-before-make.

    http://code-elec.com/content/00/01/53/48/38/userimages/DSC04782a.JPG

    That's what I need. That would fit in a small box.

    How do these Honda/Yamaha gensets stand up to the rain? Are they weather proof or do they need to be kept completely dry?
  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha

    You can also get simple 120 VAC double pole relays (no enclosures--good idea to transfer both the neutral and hot leads--some devices like MSW inverter do not share grounded neutrals very well with ground DC battery buses).

    The Honda (at least the one I have) is pretty well a plastic shell that would protect against rail/wind--However I would arrange a cover. You probably would pull water in through the fuel tank vent in the cap and the AC outlets and switches would not last very long if they got multiple soakings.

    I would assume that the above would apply to most portable generators as they cannot spare the weight/size for weather proofing of their vulnerable components.

    You can buy or even build your own generator tent for bad weather conditions.

    Probably a cable lock would be a good idea too...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Generac plus Yamaha

    One thing that might get you is the Yamaha inverter is floating neutral. It is because of the inverter/generator H-bridge output design.

    I am still a bit confused on what you use for AC power when not on shore connection. I assume the Generac RV gen has both AC and DC outputs and you have to run the Generac for AC when standlone. (ie. you don't have a 12vdc to 120vac inverter which hasn't been mentioned, and batteries run 12 vdc lighting)
  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha

    I think the issue is Propane for the RV genset and gasoline for the Yamaha portable set...

    Propane is also used for cooking and heating--and may be more of a pain to keep tanked up at times vs just hauling a 5 gallon can of gasoline to the local pump.

    Also, if the Yamaha is significantly smaller (6kW RV set vs 3kW Yamaha)--the smaller genset is probably much more fuel/cost efficient vs the larger genst when running normal (smaller) loads (i.e,, no A/C needed in winter).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Explain the floating neutral please.

    Your are correct. This is in a 33' 5th wheel toy hauler that I use at the dunes where there is no hook-up. I use the Generac for AC and DC to charge the two Trojan T105 batteries. I do have a 300W inverter to run my TV and laptop. The only time I run the genset is for the microwave and to charge the batteries, and occasionally the AC unit.

    The Generac is propane and noisy. That is why I bought the Yamaha. I was at the dunes for 10 days for Xmas/New Years and ran out of propane. I have no intention of trying to use the Yamaha to run the AC unit.
    I am still a bit confused on what you use for AC power when not on shore connection. I assume the Generac RV gen has both AC and DC outputs and you have to run the Generac for AC when standlone. (ie. you don't have a 12vdc to 120vac inverter which hasn't been mentioned, and batteries run 12 vdc lighting)
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha
    BB. wrote: »
    I think the issue is Propane for the RV genset and gasoline for the Yamaha portable set...

    Propane is also used for cooking and heating--and may be more of a pain to keep tanked up at times vs just hauling a 5 gallon can of gasoline to the local pump.

    Also, if the Yamaha is significantly smaller (6kW RV set vs 3kW Yamaha)--the smaller genset is probably much more fuel/cost efficient vs the larger genst when running normal (smaller) loads (i.e,, no A/C needed in winter).

    -Bill

    There is no issue with the propane vs gasoline. The issue is having to watch how much I run the genset to charge the batteries and heater vs how much propane I carry.

    I have to remove and have the two 7 gal propane tanks filled before each trip. I have a V8 powered sandrail and carry over 30 gal of gas in the back of my truck, so there is always plenty for the Yammie.

    The RV genset it 4.5KW and the Yamaha is 2KW max, 1.6KW rated. It's not a cost issue at all. I'm not rich, but I do like to camp hassle free as much as possible, and not annoying the neighbors and not having to worry about propane is my goal. A lot of other guys use the Honda and love it. You can barely hear them running.
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    I have 5 sewing machines.(don't ask) and can sew up canvas, naugahyde, etc for a cover. Have to make sure it gets enough air to keep from over-heating. I can always shut it off and either run off batteries or the Generac.

    Just looking at the generator, it won't like the rain. Will see what the manual says.

    Disclaimer: This may be against code and is for educational purposes only. (Is there code for a 5th wheel trailer?)

    What about two DPST ckt breakers mounted like this and wire up in a box. [IMG]http://members.cox.net/mcb56/Ckt Breaker.jpg[/IMG]

    I tested them and they definitely break before make. I think the grounds could be common.
  • hillbillyhillbilly Solar Expert Posts: 334 ✭✭
    Re: Generac plus Yamaha

    So I'm still a tad confused, and just to further confuse things... did you say that you are using the 12V receptacle from your generator to charge the batteries? It wasn't entirely clear to me.
  • BB.BB. Super Moderators, Administrators Posts: 29,514 admin
    Re: Generac plus Yamaha

    I intended to imply that the issue was you had more gasoline than propane for your trips... And a small genset driving small loads was more fuel efficient (less fuel to transport).

    The common neutral issue...

    A normal home has the center tap of a 240 VAC transformer grounded at the pole at your home electrical panel. There are good safety reasons to do this--if there are any shorts to grounded metal, it would pop the circuit breaker and be "safe".

    Also, it ensures that there are no "floating voltages". For example, if the A power lead of a center tapped transformer was grounded accidently in a floating neutral system--the neutral lead would be at 120 VAC and the B lead would be at 240 VAC with respect to ground (instead of a maximum of 120 VAC to ground for a standard 120/240 VAC split phase home system).

    The off-grid issue is that 1) Typical MSW inverters when the "neutral" output is grounded and the Battery negative terminal is grounded--it creates a dead short between the DC - and the AC "neutral"--releasing the magic smoke.

    Not all MSW inverter have this issue (bigger more expensive with internal transformer units have isolated outputs and can be OK to neutral bond--see instruction manual for details). And Most TSW type Inverters have isolated outputs so a common DC ground and AC ground does not cause any issue.

    For gensets--there are two issues again... One is the Inverter type Genset (honda/Yamaha/etc. inverter series types). There could be an issue with ground referenced neutral outputs--but I am not sure--My Honda eu2000i manual is very unclear about the issue (says talk to your electrician about it--if I recall correctly). I don't know if the generator frame and earth ground are referenced to the Generator Neutral or not (I run my genset ungrounded to avoid ground loop issues--but that is not to code).

    The other issue is that electrical connections get really complex. And it is possible that a neutral earth connection from the genset can accidentally carry DC battery bank return currents. A genset may have 15-30 amps of current... A DC battery bank can have 300 amps of current. And if there is a DC/AC ground loop/path--it is possible to get 300 amps of DC current through your genset's grounding, neutral, or even some DC through the windings. This can overheat can cause the wiring/control cirucuits to fail (and there are no fuses/breakers in ground paths to prevent over current on ground/neutral leads and DC current through the windings can saturate the field pieces causing everything to overheat).

    I have to go now--but that I the Grounded Neutral questions that always come up and have no simple answer (the simplist answer is single point grounding. Have the ground from the generator run to the ground point and run a single DC battery ground to the same common point. Do not run several grounds from the genset and/or battery bank to multiple points where you can get stray currents flowing).

    With 12 VDC -- you have many automotive devices which assume the metal chassis is ground--so you end up with DC ground current flow--which is why one AC ground only so that you don't get parallel current flows.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    The shore power cord has to plug into a female receptacle in the compartment where the cord is stored to get the AC from the genset to the inverter.

    I will use the supplied adapter that I use at home for AC to go to the extension cord that goes to the Yamaha.
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    BB, I'm going to do what everybody else does: Plug an extension cord in the the generator and plug that into the shore power cord.

    Thanks for the explanation, I got most of it. I always have my VOM with me and can check if there is any current flow from the ground of Y to the ground of the trailer.
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha
    hillbilly wrote: »
    So I'm still a tad confused, and just to further confuse things... did you say that you are using the 12V receptacle from your generator to charge the batteries? It wasn't entirely clear to me.

    Caught cha... The Generac puts out 2A max to charge the batteries, but when the Generac's AC output is connected to the shore cord through the receptacle, the inverter puts out 45A max to charge the batteries and power any AC appliance.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Generac plus Yamaha

    I thought that Genrac DC output amperage strange too but just assumed the RV gen version had higher 12v charger capability.

    The less then 3kW inverter/generators do not have a groundable neutral (the wider AC prong). If you take an AC voltmeter you will read about 60 vac from either plug side to ground prong or metal case of generator.

    Your shore plug, RV generator, and/or charger may have the neutral side of A.C. grounded to chassis of RV.

    The actual two prongs of A.C. output from inverter/generator are floating except for filter caps that go from either hot/neutral prong to gen chassis/ground.

    You may damage the inverter in the generator if you hard tie the ground prong to the neutral prong on the generator. The potential damage is caused by the capacitance of the stator windings to the chassis.

    With your RV on rubber wheels and generator on wet ground you might get a tingle stepping off the RV if the RV chassis neutral is tied to its chassis.
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Per the Generac manual and name plate, 2A max 12V DC output, and that is what I see on my Bogart panel. That would suck if your inverter went out in the middle of a long weekend. Bye-bye batteries.

    So, what you are saying is that I should not ground the Yamaha generator ground to the trailer/Generac ground. I should use a non-polarized extension cord. Correct?

    I'm thinking that Yamaha would incorporate the ability and/or protection to allow for a three prong extension cord to be plugged into the EF2000iS and then to a three prong adapter on the shore cable. I'll know more when I get it and read the "rules". Nobody had complained of getting zapped running their Honda 2000s.

    I ordered it Tuesday, 1/5/10 from DHC Supplies and they sent me an email that said: "We will make every effort to ship your order either the same or next business day (Excluding Yamaha Generators)". I called and they said Yamaha generators are shipped directly from the warehouse in Wash St. and they take at least two days to process an invoice, so I have no idea when I will get it. Next dune trip is next Wednesday or Thursday. This may require a phone call.

    Here is a pic of the control panel of the EF200iS. Looks like it has a three prong receptacle.

    http://www.yamaha-motor.com/outdoor/products/modelimagelib/626/13/1/0/image.aspx
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Generac plus Yamaha
    Just Me wrote: »
    Per the Generac manual and name plate, 2A max 12V DC output, and that is what I see on my Bogart panel. That would suck if your inverter went out in the middle of a long weekend. Bye-bye batteries.

    Another consideration is that the battery charging output of most of the small inverter generators (and possibly your Generac as well) is unregulated. It will charge a battery - but it's not a great way to do it. The best way is probably to just run the trailer from the 120v of the generator, and let the built-in 120v-12v converter/charger (which your trailer almost certainly has) handle the battery charging.

    So, what you are saying is that I should not ground the Yamaha generator ground to the trailer/Generac ground. I should use a non-polarized extension cord. Correct?

    I'm thinking that Yamaha would incorporate the ability and/or protection to allow for a three prong extension cord to be plugged into the EF2000iS and then to a three prong adapter on the shore cable. I'll know more when I get it and read the "rules". Nobody had complained of getting zapped running their Honda 2000s.

    Using a 3-prong grounded extension cord won't be an issue unless both generators are running at the same time AND one of them has a problem.
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Just as a test, I ran the Generac without the shore plug plugged into the receptacle and it was only a 2A charge. Normally, it is plugged into the receptacle and the inverter output is up to 45A DC regulated charge to the batteries.

    There is no way, unless I jerry rig a cable that both the Yama and the Generac would be inputing the inverter at the same time. The AC from the Generac goes to the receptacle and if the shore cable is not plugged in, the inverter doesn't get anything.

    Unless I need to run the AC unit, the Yama will provide enough power to the inverter to charge the batteries and run everything else without bothering the neighbors when I stay up till 3-4 am. Yea, bright lights at night so I can see my keyboard. :D

    As a side note, what wide angle LED 1156 lamps are available at a reasonable price. I really only need one for behind my couch when using the laptop. Last time I checked, one was about $15 with almost as much for shipping.
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: Generac plus Yamaha
    Just Me wrote: »

    So, what you are saying is that I should not ground the Yamaha generator ground to the trailer/Generac ground. I should use a non-polarized extension cord. Correct?

    I'm thinking that Yamaha would incorporate the ability and/or protection to allow for a three prong extension cord to be plugged into the EF2000iS and then to a three prong adapter on the shore cable. I'll know more when I get it and read the "rules". Nobody had complained of getting zapped running their Honda 2000s.

    Just check with an ohmmeter on your RV that neutral (white wire ) is not connected to RV chassis ground and you will be fine. With the RV generator and charger you need to check with the ohmmeter that one of them is not grounding the neutral.

    To use an inverter/gen, like these, the system should have a floating neutral. This is not the case for house wiring as the neutral is grounded at the breaker box.

    A 240/120 v inverter/generator can be neutral grounded. The only one I know of is the larger Honda EU6500i.

    I have a Yamaha EF3000i inverter/gen connected into my house system but I use an isolation transformer to keep the inv/gen neutral floating.
  • Just MeJust Me Solar Expert Posts: 48
    Re: Generac plus Yamaha

    Just checked. It's not grounded.

    Thanks for the reply.

    Yami should be here Tuesday. :D
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