Generator vs. AC question...Opinions wanted

[Acableguy06]

Originally Posted by tperk100

Also will probably convert both to tri fuel.

I do believe you will have to derate your genny's power on LP and especially on NG. Lp has less BTU's than gas and NG is less BTU's than LP. Less BTU's = less power. This may not apply to inverter generators you will want to look into it further. I know it does on regular generators.

[STG]

tperk - Yes, we were between larger generator and different AC, but I too called RVP products that makes the Airxcel Coleman AC that we have and talked to a guy that explained the same to me of multiply by 2.5 and the max amps would be around 33 initially with compresser and fan. When questioned specifically he did confirm that this model is WITHOUT capacitors allowing the starting amps to run for a minute instead of a second thus causing the trip. I explained I have a Honda 3000 and he said it will run it and that I should not think about another AC, just add the capacitor a $20 fix + labor if having it done. I asked about warranty and he said that this mod wouldn't affect it. His comment was, " don't hold me too it because I work for this company, but I wish we had never made these without capacitors". I assume he has talked to other frustrated people since the usual generator talk centers around BTU and "these generators should run most 13,500 BTU", (EXCEPT THESE MODELS WITHOUT CAPACITORS Since there has been talk about this being Coleman and calling them out, I found it interesting that he explained that the changes have been made at the OEM's request ie. Jayco, Forest River so that they could produce quicker. Anyway my options of a new generator at $3000, new AC at $1000, or a capacitor at $150 has made our decision for us. Since I don't plan to do this myself, the service department has called RVP products and the specific part has been ordered. Of note it does not require any additional wiring or harness and should be a simple install to bring those starting amps down to a second that the generator can handle. If you decide to parrellel your 2000 and still have issue, then this mod would do the trick I'm sure. I suppose we have learned any RV purchases in the future to ask about capacitors on the specific model to know whether start up amps are a second or a minute!

[tperk100]

Tracey,

I also learned form the Yamaha rep that if start up current is higher than the max gen rating, REGARDLESS of whether it is demanded for one minute or less than one second, then the generator will be overloaded. Even if it seems to work it will be hard on the gen and/or the compressor and fan motors. Therefore it seems to me that, even with the capacitor, we will need at least a 4000 gen.

It will also make a large beneficial difference to install a mod (if such a mod is available) that starts the fan and the compressor motors sequentially as opposed to simultaneously. This will actually reduce starting amperage by about 6 amps. Your 3000 might even work with this mod.....without being overloaded.

[TURBS]

Remind me to not buy a camper with a Coleman mach.

[wneise]

Originally Posted by f1100turbo

Remind me to not buy a camper with a Coleman mach.

If you get the Dometic with the digital thermostat, don't plan on doing the power on make timer mod to delay the startup of the fan. The fan and compressor are controlled by a 3 wire digital signal from the thermostat to the controller, not the typical 6 wire you find in most thermostats. The only wiring to the fan from that controller is low medium and high at the rated amperage which is greater than the 1 amp limit of the timer for each setting.

[garbonz]

If you have an inverter, could it be rigged to augment the generator power to get the AC up and running. Just asking an interesting question.

[wneise]

Originally Posted by garbonz

If you have an inverter, could it be rigged to augment the generator power to get the AC up and running. Just asking an interesting question.

Unless it is a grid tie inverter, absolutely not. Both sources need to be in phase with each other and only grid ties can sense the power phase before introducing its own AC. Not to mention both have to be pure sine wave sources.
A better idea may be to have the genny plugged into a battery tender that doesn't overtax the genny and then a battery bank and ultra beefy inverter to your AC system on the other side.

[Herk7769]

Originally Posted by tperk100

It just occurred to me that the last time we used the RV we hooked up to a 20 amp household circuit with a breaker that was NOT an HVAC type. The AC seemed to run well, and we had some power to spare.

Given all of what we have discussed here, how could this possibly be??

Just for the fun of it I ran the microwave at the same time. As expected it tripped the house's breaker.

House (and RV) circuit breakers are "slow blow" and even though the drawn amps exceed the rating, they do not "trip open" until the bimetallic switch heats enough from the over current to bend open.

The inverter protection in most generators will trip on overload instantly.

[bend302]

Herk: Just a comment. While I like your Despicable Me Avatar, my favorite was the flight gear.

Now, I have been reading this post with interest because when we returned from a trip one day last Summer, we were tired and just pulled the Georgetown into the storage and plugged in the electric to keep the refer running so we could get some sleep and clean things out tomorrow.

However, when I plugged into the 120 VAC 20A supply my rear A/C started right up. Later I discovered that I had also failed to turn off the WH. Just lucky, I guess.

Bill

[Herk7769]

Originally Posted by bend302

Herk: Just a comment. While I like your Despicable Me Avatar, my favorite was the flight gear.

Now, I have been reading this post with interest because when we returned from a trip one day last Summer, we were tired and just pulled the Georgetown into the storage and plugged in the electric to keep the refer running so we could get some sleep and clean things out tomorrow.

However, when I plugged into the 120 VAC 20A supply my rear A/C started right up. Later I discovered that I had also failed to turn off the WH. Just lucky, I guess.

Bill

Or...

1) The water heater element is bad
2) The breaker is bad (stuck closed)
3) The breaker has a high tolerance for over voltage.

My camper (since I monitor incoming AC amps) can easily pull 28 amps starting (for a few seconds) and not blow the 20 amp breaker protecting my 12/2 w/Ground run to the RV wall socket.

PS (I liked the little guys - all engineers of one kind or another)

[STG]

tperk100,

Good news! Service department couldn't get RVP techs to give them a part # for a start up capacitor since our model was designed without. They were referred to the engineer that designs the units. Service manager said in all I his career it was the nicest engineer from a part company. The engineer understood our situation and actually sent the part free of charge. We only needed the startup capacitor as the other capacitors, housing, and wiring are on the unit. It has been installed and we now have start up at 14amps (I am sure higher for a second), but the first minute is 14 amps and then we back down to 11amps. Successful trip to the woods this weekend with the generator! Now to move on and figure out a few other things such as the air hide a bed sofa, not sure we are pulling it out right .

[tperk100]

Tracey,

Great news! Do yo think you could get or give me some contact info to help me do the same thing?

Thanks