Running A/C on inverter while driving

[Tarjas]

I am considering upgrading my Xantrex Freedom X 1200w to a 2000w so the microwave can be used without starting the generator.

l would also like to be able to run one of the 2 11000k btu ACs that my 29F has while driving during the Florida summer without running the generator if possible. Total power usage shouldn't be a problem as the AC only pulls an average of 8 amps AC - probably around 90 amps from the inverter. I have 240ah of lead acid batteries.

Anyone have any advice on this plan? Haven't been able to find much on the net but what I have found suggests the 90 amp load along (more at the alt with voltage drop) and engine/chassis electrical demand may be too much for an extended period.

Don't think I'll pay for the wattage increase just to run the microwave, guess I've talked myself into a circle here! Thank you for any comments!

[craigav]

The problem is that running the alternator at or close to 100% of its rated output will cause it to overheat and that will cause it to fail or simply not last very long. Most recommendations I have read indicate that an alternator shouldn't run much more than 60% of its rated output for any extended period of time.

[Grumpy]

Your going to need a "big inverter". due to the start surge.

[Mike-NM]

A 10,000 BTU Unit has surge wattage of 1800 watts and a running wattage of 1200 watts. A 12,000 BTU unit has surge wattage of 3950 watts and a running wattage of 3250 watts. DC: I = 3950 W / 110 V = 35.91 A

[mkassab]

Originally Posted by Tarjas

I am considering upgrading my Xantrex Freedom X 1200w to a 2000w so the microwave can be used without starting the generator.

l would also like to be able to run one of the 2 11000k btu ACs that my 29F has while driving during the Florida summer without running the generator if possible. Total power usage shouldn't be a problem as the AC only pulls an average of 8 amps AC - probably around 90 amps from the inverter. I have 240ah of lead acid batteries.

Anyone have any advice on this plan? Haven't been able to find much on the net but what I have found suggests the 90 amp load along (more at the alt with voltage drop) and engine/chassis electrical demand may be too much for an extended period.

Don't think I'll pay for the wattage increase just to run the microwave, guess I've talked myself into a circle here! Thank you for any comments!

Tarjas,

First, I suggest you read my thread where I have a lot more detail on how Inverter is wired in. Link: https://www.jaycoowners.com/forums/f...34g-81805.html

If you want to run all that you say, you'll need to wire in the inverter like I did... i.e., direct to the 120vAC circuit panel vs how Jayco has their inverter wired.

Honestly, in my opinion, it would be much easier and cheaper to just run your generator. And running the A/C on your current battery capacity.. well, let's say by the time the A/C started to get the coach cool, the battery will be dead. They sell electric surge reducers for the A/C and I'm installing one on each of my two A/C units for several reasons (which I'll document in my link when I install them in April) The Surge reducers I bought are https://www.microair.net/products/ea...nt=30176048267 There are other brands out there.

So, consider the big picture.... and future options like batteries, solar, multi inverters, etc.

Mark

[Allen_C]

Your battery capacity of 240Ah is only 120 at 50% SOC. If the air conditioner draws 90A continuous, that will only give you about 1hr and 20min of usage. Also, as stated above, the start-up amperage draw is much higher and a 2000w nominal inverter will not put out enough to start the AC, unless you install a Micro-Air or similar soft starter.

I've gone down this exact path but I also have a 400Ah Lifepo4 battery and solar on the roof. Generator usage is much more cost and power efficient!

[Tarjas]

Thank you all for the comments- my intent if I wasn’t clear was not to rely on the batteries for AC while stationary, intent was to run the AC while driving. I probably could get away with short stops with the 120AH I have available if needed.

The V8 F53 comes with a 210amp alternator, seemingly enough to run the 7-8amps 120vac the single 11k Mach 1 pulls (80-90 12v amps). Not too worried about start surge as the ACs have a built in start kit. I can easily run the 9 amp 1 AC and normal house load on 1 EU2000i (ecothrottle needs to be off when the AC starts). Xantrex 2000 claims 4000watts for 2 seconds so start surge “shouldn’t” be an issue.

After doing some more research I think I’d would be pushing the alternator too hard by pulling close to 100 amps (or however much it could give me) on top of engine loads, AC blower, lights/etc. Sudden alternator failure wouldn’t be worth the small advantage of not running the Onan. (The 4K onan is about .5gph running the AC).

Eventually I will likely upgrade to lifepo4 so I could get a dc-dc charger to limit the load on the inverter but the cost of the 2k inverter and charger doesn't make a lot of sense right now. I just picked up 4 100w solar panels and a Victron 100/30 MPPT though here in Florida it will be almost next year before I can really use them unless I can make it up to the mountains this year (too hot to not have ACs going!)

I do have a 36v 60AH LIFEPO4 that I use for my trolling motor on my boat- too bad I can't find a way to cost effectively use it on my RV!

[Tarjas]

Originally Posted by Mike-NM

A 10,000 BTU Unit has surge wattage of 1800 watts and a running wattage of 1200 watts. A 12,000 BTU unit has surge wattage of 3950 watts and a running wattage of 3250 watts. DC: I = 3950 W / 110 V = 35.91 A

11k BTU Mach 1 PS 1080watts (9 amps) normal conditions (11 amps desert). Pleased with these units as it makes mooch docking very easy - can run 1 of the ACs and fridge off host 15amp connection. Also don't have to parallel my EU2000s to provide power and cooling while working on projects/etc at the storage lot.

Power management system can be set to 15, 20, or 30 amp service to load shed and keep host's breakers from popping in the middle of the night. Would like the 6500 extra btu of the 50amp variant when the RV is first powered up and hot but the chassis AC is strong enough to make up for it when cooling things down. No issues at all once things cool down.

[Tarjas]

Originally Posted by mkassab

Tarjas,

First, I suggest you read my thread where I have a lot more detail on how Inverter is wired in. Link: https://www.jaycoowners.com/forums/f...34g-81805.html

If you want to run all that you say, you'll need to wire in the inverter like I did... i.e., direct to the 120vAC circuit panel vs how Jayco has their inverter wired.

Honestly, in my opinion, it would be much easier and cheaper to just run your generator. And running the A/C on your current battery capacity.. well, let's say by the time the A/C started to get the coach cool, the battery will be dead. They sell electric surge reducers for the A/C and I'm installing one on each of my two A/C units for several reasons (which I'll document in my link when I install them in April) The Surge reducers I bought are https://www.microair.net/products/ea...nt=30176048267 There are other brands out there.

So, consider the big picture.... and future options like batteries, solar, multi inverters, etc.

Mark

Thanks Mark. Your thread is very informative and I certainly will use it as a resource! As I’ve done more research it does look like just running the gen is the easiest/most cost effective answer.

[Foretm]

Originally Posted by Tarjas

11k BTU Mach 1 PS 1080watts (9 amps) normal conditions (11 amps desert). Pleased with these units as it makes mooch docking very easy - can run 1 of the ACs and fridge off host 15amp connection.

x2, love the 11K BTU powersavers and energy management system. Seems to have been done away with on the Entegra Vision line, but Jayco still uses it on the Allante line. Makes finding a campsite at some state parks easier too... alot of them in florida are still 30amp....

[craigav]

Hi Tarjas, I wasn't aware that the F53's had a 210 amp alternator, the E450's have 130 amp (if I remember correctly). In any case, with a strong enough inverter and perhaps a microair easy start kit, and assuming yours would only draw ~90amps, then add the in-dash A/C running perhaps 15 amps, and the daytime driving lights at ~10 amps, perhaps a few other acc's ~5 amps, total would be around 120 amps and from a 210 amp alternator that would be less than 60% of the alternators maximum capability. A 120 amp draw should work just fine with a 210 amp alt being at ~< 60% of its maximum output rating. One point to share is if I was to do this, I would wait until the coach and chassis batteries were back up to their fully charged voltage prior to turning on the A/C eliminating most of the battery charge amps current from being pulled from the alt at the same time.

On the other hand, using the onboard generator is what I do and most others do, simple to use and is already in place. Running the generator and my A/C (15k btu) costs me roughly 1~1.5 mpg. It is also a convenient way to keep the A/C running when stopping at rest areas and for similar stops. ~CA

[Tarjas]

Decided that I am going to leave everything as is. I do want to wire the fridge circuit to the inverter so I can run it on AC going down the road vice propane. Any advice on how to accomplish Mark? I haven’t pulled panel to look at how by the breaker box is fed but surely it can’t be that difficult.

[mkassab]

Originally Posted by Tarjas

Decided that I am going to leave everything as is. I do want to wire the fridge circuit to the inverter so I can run it on AC going down the road vice propane. Any advice on how to accomplish Mark? I haven’t pulled panel to look at how by the breaker box is fed but surely it can’t be that difficult.

You can do it, but think twice. Not sure the Inverter will run the A/C... i.e., not enough amps with A/C surge.... but it's easy to test. Just turn your refrig off at the refrig, i.e., no power draw. Also, if you do this, the refrig/tv/etc will only run when connected to shore power or generator.

Your inverter feeds 120vAC pwr to refrig, TVs, 120v receptacles by beds, table, sofa, etc.

Turn off master power switch off. Turn off the circuit breaker to the inverter and the A/C unit.

Now you can do the following as a test:
1. For a temporary test, remove hot wire from the A/C circuit breaker. This is the hot 120vAC that feeds power to the A/C unit. Also remove the A/C ground and neutral white wire from the power panel.
Now, Run a 12ga (14 ga wire ok if a 15amp circuit) wire from the 120v "Out" on the inverter and the other end to the A/C hot /neutral/ground wire removed from the A/C circuit breaker/pwr panel. Wire nut the two together. It's OK to leave the Refrig wire connected to the Output of the Inverter for this test since you have the Refrig off. Your A/C is now powered by the inverter circuit vs the A/C circuit. Make sure the amp rating of the A/C circuit breaker is the same or less than the inverter circuit breaker. Turn the master circuit back on.

If the inverter operates the A/C OK and the batteries and engine alternator can keep up and running for long periods and you want to make this temp test to perm.... do the following.

You can keep the inverter connected to the A/C wire from the test above, but to be legal/in code, add an electric box and cover so the wire nuts are inside. Then, you could take the original 120vAC wires from the inverter and connect it to the same connections that the A/C was connected to I.e., hot/neutral/ground. Again, only if the circuit breakers are the same amp rating.

Mark

[Tarjas]

Mark- fridge is gas absorption, no issues with surge. No problem with the 1200w Freedom - tested with extension cord plugged into one of my inverter powered outlets connected to fridge power cord (it has a standard 110 plug in and a power outlet behind the outside fridge access panel. ,)

My fridge is not on the "rail" the comes from the inverter, it always gets its 120v from shore power and reverts to 12v/gas when that is not available. I think the inverter is upstream of the breaker box where some of the breakers are fed from shore power and some are fed from the inverter/shorepower.

I just brought the RV to the house so I'll pull the panels out of the bed and see if I can figure it out. Essentially I am trying to set it up the same way RVs like yours are with the residential fridges.

[mkassab]

Originally Posted by Tarjas

Mark- fridge is gas absorption, no issues with surge. No problem with the 1200w Freedom - tested with extension cord plugged into one of my inverter powered outlets connected to fridge power cord (it has a standard 110 plug in and a power outlet behind the outside fridge access panel. ,)

My fridge is not on the "rail" the comes from the inverter, it always gets its 120v from shore power and reverts to 12v/gas when that is not available. I think the inverter is upstream of the breaker box where some of the breakers are fed from shore power and some are fed from the inverter/shorepower.

I just brought the RV to the house so I'll pull the panels out of the bed and see if I can figure it out. Essentially I am trying to set it up the same way RVs like yours are with the residential fridges.

OK, now I'm confused on your goals/purpose to change really is. I'll send you a PM with my phone number as I think a discussion would be better than many emails/posts.

Mark

[JesseS]

I have a 2500 watt inverter, wired via a 30amp plug in the shore power compartment. While driving I plug the shore power cord into it, thus giving me 'whole house' 110 power. Also added a 'soft start' kit to my 1500 btu A/C unit although I don't anticipate running the ac off of the inverter, but a test shows it will run fine with a running load of about 120 amps. I wired it this way for two reasons, one I can use any 110 device I need to, and with a 30 amp coach I don't have a split panel to worry about, makes it simple. I can run the fridge on 110 while driving (pulls 28 amps) or let the Instapot slow cook dinner while we travel (my DW loves this option). One thing I do use it for is recharging the electric bike batteries while driving to the next destination. With 400 AH of LiFePo4 batteries we have plenty of power for out needs. My generator is 5 years old now and only has 40 hours on it, we don't need it much

[Allen_C]

Originally Posted by JesseS

I have a 2500 watt inverter, wired via a 30amp plug in the shore power compartment. While driving I plug the shore power cord into it, thus giving me 'whole house' 110 power. Also added a 'soft start' kit to my 1500 btu A/C unit although I don't anticipate running the ac off of the inverter, but a test shows it will run fine with a running load of about 120 amps. I wired it this way for two reasons, one I can use any 110 device I need to, and with a 30 amp coach I don't have a split panel to worry about, makes it simple. I can run the fridge on 110 while driving (pulls 28 amps) or let the Instapot slow cook dinner while we travel (my DW loves this option). One thing I do use it for is recharging the electric bike batteries while driving to the next destination. With 400 AH of LiFePo4 batteries we have plenty of power for out needs. My generator is 5 years old now and only has 40 hours on it, we don't need it much

Your setup is almost identical to ours! Except we have a 2000w pure since wave inverter. I also have about 600w of solar on the roof!

[JesseS]

Originally Posted by Allen_C

Your setup is almost identical to ours! Except we have a 2000w pure since wave inverter. I also have about 600w of solar on the roof!

I was going to put in a 3KW inverter but the PSW 2500 seems to handle everything just fine. I have 4X200 watt panels on fixed mounts, makes up for not tilting them. With a 40 amp solar controller I am back to 100% SOC by noon in most cases while boondocking. I do have a flexible soft case 240 watt folding panel for when parked in the shade, has a 100' cord and plugs directly into a pigtail on the controller input. I wired my panels in parallel to avoid loss of power if one panel is shaded. All in all very happy with my setup, been using it for years without issue.

[Tarjas]

Originally Posted by JesseS

I have a 2500 watt inverter, wired via a 30amp plug in the shore power compartment. While driving I plug the shore power cord into it, thus giving me 'whole house' 110 power. Also added a 'soft start' kit to my 1500 btu A/C unit although I don't anticipate running the ac off of the inverter, but a test shows it will run fine with a running load of about 120 amps. I wired it this way for two reasons, one I can use any 110 device I need to, and with a 30 amp coach I don't have a split panel to worry about, makes it simple. I can run the fridge on 110 while driving (pulls 28 amps) or let the Instapot slow cook dinner while we travel (my DW loves this option). One thing I do use it for is recharging the electric bike batteries while driving to the next destination. With 400 AH of LiFePo4 batteries we have plenty of power for out needs. My generator is 5 years old now and only has 40 hours on it, we don't need it much

Did you add a relay for your converter or do you have separate battery banks and leave it on? I have run an extension cord from my inverter hot outlets to my 30 amp plug. Inverter wasn't happy when the convertor was on...

[JesseS]

Originally Posted by Tarjas

Did you add a relay for your converter or do you have separate battery banks and leave it on? I have run an extension cord from my inverter hot outlets to my 30 amp plug. Inverter wasn't happy when the convertor was on...

No wonder your inverter wasn't happy, your converter was trying to replace the power the inverter was using, won't work, viscous cycle ending in dead batteries. I installed a 110v 30amp normally closed relay on the converter socket, and powered it from the inverter. So when I power the inverter it automatically cuts power to the converter, and restores it when the inverter is turned off. This way I don't have to remember to turn off the breaker for the converter prior to using the inverter.