Generator for 15000 BTU a/c

[ruffian]

In either "Trailer Life" or "Motorhome Life" or "RV's", there was an article regarding using a 3 kw gas generator to run his AC unit plus charger. The test was done in AZ. Hot desert. The article claimed the generator did a fine job. There were two different generators involved in the test and both performed well.

Sorry I can't be more specific about the issue but I just bought the magazines a couple days ago so they are the current issues.

Read the article if you can. It should answer your questions.

Keith

[Libero]

Ray.IN

That bolly genset looks to be a great unit. I don't have a need for an external generator, but if I did, the Bolly would be on the top of my list to investigate.

The documentation says super quiet. Have you compared to the noise a honda of the same size makes?

Thanks

[TEAMTJ]

I have a 2012 Wild Cargo with a 15k and 13.5k a/cs. We didn't get the installed genny option and instead use our Honda 3000is to run one a/c at a time. We have had no problems with the load of running one a/c with our 3000is.

[Groovy]

We have a Yamaha 2400i gas generator and it runs our 15000 BTU a/c unit just fine. We used it probably 10-12 times last year to run our air conditioner, using it for 4-8 hours each time.

Sometimes we have to finesse the a/c a little to get the generator to accept the big power spike when the a/c first turns on. That is, we turn on the fan only first and then turn on the a/c. But most of the time the a/c comes right on without a hitch.

Once it's running it purrs along just fine as long for hours...

We've been extremely happy with this generator. It starts first time every time, even after sitting unused as long as 20 months.

[Ray,IN]

Originally Posted by Libero

Ray.IN

That bolly genset looks to be a great unit. I don't have a need for an external generator, but if I did, the Bolly would be on the top of my list to investigate.

The documentation says super quiet. Have you compared to the noise a honda of the same size makes?

Thanks

Compare the specs for both gensets for db level. Mine is very quiet, We have had it running underneath the RR corner of the 5er (cabled to the RR stabilizing jack so it doesn't walk away) while boondocking and can't hear it above the range vent fan. I kinda wish it would break, so I would have an excuse to buy the electric-remote start model.
However, for the price of those used Honda 2000's, and you are close enough to IL to drive to pick them up, that's what I'd buy. Still might myself.
BTW, Any stand-alone genset must be open to the air, not operated in a confined space.

[Libero]

thanks - my built in 4kw onan is very quiet and it is air cooled - my 7,5kw onan was liquid cooled and it was super quiet alao.

i Have a 22kva (17kw) liquid cooled propane unit for my S&B backup. have it in a sound proofed room in my RV garage and it is not quiet when inside the room. Cannot even hear it when in my house so unless I see the gen light on, I would not know if I was on main or bu power.

17KW is overkill for home but I got a great deal on it and it runs with a light load most of the time.

[gonfercoffee]

Speaking of Super Quiet....my Robyn 5500 makes a racket and gets the job done sort of..... We use it every couple years when nobody's around.

Last time we used the generator I noticed that the a/c would work but not much else. I figured that the fridge and microwave were fussy for exact voltage, so i ran all the other appliances on propane for the duration. Didn't seem to harm anything in the long term, but it's been bugging me. Thought Libero might have a clue for me.

How do you determine if the 220v circuit is out of balance? I'm wondering if my wiring is loaded on the white wire side (neutral?) and my generator is loaded on the black wire side. Sorry if I've butchered the terms! i made a jumper cord to plug into the Excel shore power cable, so maybe i've got something crossed?

[Libero]

Originally Posted by gonfercoffee

Speaking of Super Quiet....my Robyn 5500 makes a racket and gets the job done sort of..... We use it every couple years when nobody's around.

Last time we used the generator I noticed that the a/c would work but not much else. I figured that the fridge and microwave were fussy for exact voltage, so i ran all the other appliances on propane for the duration. Didn't seem to harm anything in the long term, but it's been bugging me. Thought Libero might have a clue for me.

How do you determine if the 220v circuit is out of balance? I'm wondering if my wiring is loaded on the white wire side (neutral?) and my generator is loaded on the black wire side. Sorry if I've butchered the terms! i made a jumper cord to plug into the Excel shore power cable, so maybe i've got something crossed?

I assume your 5.5KW gen is 240v when you refer to balanced load.

If one is using a 220vac generator ( likely is 240 v with 2 120v legs). There would be 4 output wires on the 240v plug. . White would be common. Black would be L1 and likely Red as L2. 240 volts would be measured across L1 and L2.

White would be common. So if you measure between L1 and white you would be measuring one side of the 240v circuit which would measure 120v. The other side (AKA leg) would be between L2 and White and it should measure 120v also.

The forth wire would likely be green. Ground.

If you drew current from one leg at a disproportionate amount to the other leg, the generator might have a problem with this and internal generaror faults could result.

I have never seen an RV operating on 240v as taking the power from L1 and L2.

How have you wired power from your gen to your RV? A diagram would help.

On a 5500 watt 240 v Gen, only half the wattage would be available from each leg. But this would be the Max load for that leg.

If you have a kill-a-watt meter you can plug into each leg of the circuit you will see if there is a load imbalance.
120v gennys for RV,s don't have this problem.

I suspect you are only using one leg of the 240v cct and your AC plus Converter and your Microwave will cause problems.

Hope this helps.

[Libero]

I also suspect the 5500 W gen is the max rating. Not the RUN rating. - but I am not familiar with your generator - run power would likely be at least 10% less likely about 4900 W.

It may have 120v output plugs and a 240v plug. But if you are only using a black and white wire I suspect you are using 1 of the power legs onky.

Is it possible to select 120v only in your generator?

[gonfercoffee]

Libero, thanks for all the good info!! I have a project that i have to finish up in the shop this am, after i've got that wrapped I'll shoot some pix and make you a schematic of my wiring job. Again, thanks for the comeback!
Steve

[gonfercoffee]

Libero...took me awhile, but I got it done.

I checked all the wires from both ends of the 50A shore power plug, and as you said, L1 and L2 produced 240v when jumped together; 120v when jumped to the common wire. Question: is the common also known as "the neutral"? I got 120v from L1 and L2 when jumped to ground.

I started the generator and found the same condition at LI and L2 and the common at the end of my home built 4 wire 35A to 50A plug "adapter" I made up. I couldn't get 120v jumping either L1 or L2 and the ground though.

I have a cycle meter I use to set the rpm on my tractor generator. At no load the meter reads in the green zone. Too cold to get the a/c compressor to start, I think??

My AmProbe would be too bulky to use inside the trailer's shore power load center.... What's a kill-a-watt meter?

Speaking of the load center, would the location of the 220v breakers be an easy way to check for a potential imbalance? Ie: too many on one side?

I added photos of my noisy old robyn gen set.

Mucho thanks in advance for helping out with this slightly nagging problem.
Steve

[Libero]

Originally Posted by gonfercoffee

Libero...took me awhile, but I got it done.

I checked all the wires from both ends of the 50A shore power plug, and as you said, L1 and L2 produced 240v when jumped together; 120v when jumped to the common wire. Question: is the common also known as "the neutral"? I got 120v from L1 and L2 when jumped to ground.

Answer:

Neutral and common are synonymous terms for this purpose. Neutral is normally a white wire and is is the center tap of the transformer serving that power source. Or in the case of a 240v generator with 120v legs. the center tap of the stator fields. When you say "jumped together", i understand you to mean measuring the voltage between those points and not "jumpering" or joining.

In general there should not be a potential difference (AKA voltage) measured between neutral and ground. Ground does not come from the utility provider. This is derived from a rod in the ground or other locally established ground point with sole purpose of maintaining safety.

End of comment on this point.

I started the generator and found the same condition at LI and L2 and the common at the end of my home built 4 wire 35A to 50A plug "adapter" I made up. I couldn't get 120v jumping either L1 or L2 and the ground though.

Answer:

Hmmm don't understand the " 4 wire 35A to 50A plug adapter". What is this? A diagram would help here.

I asume your trailer wired for 50A input?

Is your generator grounded?

Need to address this further. Could not see much from the pictures because they were dark. But I fould a manual for the Robin RGX 5500 and upon looking at the manual. There are 3 output recepticles:

1 - u ground duplex GFI protected @ 120v 20a
1 - twist Lock single 120v @ 30A
1 - twist Lock Single 120/240 20A

Which outlet are you using?

End of comment on this area


I have a cycle meter I use to set the rpm on my tractor generator. At no load the meter reads in the green zone. Too cold to get the a/c compressor to start, I think??

Answer:

Would not worry about the frequency if you have the USA UL certified unit. It should be 60hz.

My AmProbe would be too bulky to use inside the trailer's shore power load center.... What's a kill-a-watt meter?

Answer:
I suspect your "AmProbe" is an induction loop to pick up current for your ammeter. End of comment here

A Kill-A-Watt is a brand name tester that you can plug into any u-ground ac recepticle and it is in lone with the load and it will measure.Watts. Voltage, current and frequency. Cheap and handy to have to measure circuit load. End of comment here.

Speaking of the load center, would the location of the 220v breakers be an easy way to check for a potential imbalance? Ie: too many on one side?

Answer:

Yes you could pick up the current for each leg at the 2 ea 20A breakers but if you taking power from the 120/240v receptical, you would only get 20A per leg. But best to know which plug you are using and your wiring configuration before we go further with that.

I added photos of my noisy old robyn gen set.

Comment got them

Mucho thanks in advance for helping out with this slightly nagging problem.
Steve

Might be best to send me a PM with your tel and we can discuss. And if you have Skype we could use that also with video if you have a good data connection.

As I am certain you are aware it is VERY important to get the electrical right for safety reasons.

Love to be able to help. Hope I can help you solve this.

[Libero]

Oops made a typo - kill-a-watt in "in line" with load.

If you are getting power from the 240v twist receptical, you will only get 20A per leg from the gen vs the 50A per leg from a campground receptical. Your AC would be on one leg and possibly something else, Your Microwave, converter and some outlets will likely be on another leg. You could test this by turning off each 20A breaker on the gen, one at a time, and see what is working in the coach and what is not in each case. This will tell you what you are using from each leg in terms of load. This woukd only apply if you are using the 240v outlet of course.

How many BTU is your AC and does it have a heater coil?

If you are using the 120v 30A twist receptical, as you would in a conversion to 30A outlet from a 50A cable. Then you could draw a total of 30A. No load balancing required here because the stator field connections are effectively run in a parallel mode so equal current will be drawn.

So I need to know how you have it wired and what gen output you are using. Your comment about the home made 35A adapter cable made me wonder.

The ground wire in the Gen plugs is not bonded to neurtal in the generator according to the Gen schematic - this is why you did not measure any voltage between L1. or L2 and ground from your genny. The circuit is between neutral and L1 and L2 respectively. Your RV will be wired so there is never an internal circuit between L1 and L2. Just will not show up on the panel as such.

We should talk. Please PM me.

Best regards - we will get to the answer.

[gonfercoffee]

We are in the middle of what looks to be a nasty sleet storm, so I'm in the shop tinkering with my Case 830 that runs the PTO generator. If the power goes out we'll run the whole shebang with my 12KV IH Electrol. Both those units date from the 60's or earlier, now that I recollect...

I want to get you a photo/schematic of the "adapter" cable I made.
Now that I think of it I've been plugging it into the 220v outlet on the generator. My home made "adapter" connects the 220v outlet on the Robin to the 50amp plug on the end of the Excel's shore power cable.

50amp recepticle on the side of the trailer.
gen set wasn't grounded

I'll pm you later with a photo and phone number.

Steve