ROOF A/C from 12 VOLT through INVERTER

[sajohnson]

Originally Posted by Mr. B

I absolutely agree with Sajohnson, and as I mentioned before I’m always idling with no limits when it’s very hot outside, in order to run the vehicle’s A/C. And since it is always around 90 degrees outside while idling, my engine temperature never drops below 80.

PS: Saj, apparently you are well-educated not only with Koni shock absorbers )))... Yes, this is me - Yaroslav ))

Hey Yaroslav,

Don't make the mistake of assuming I know what I'm talking about.

In all seriousness, I try very hard to post accurate information, but while I'm a technician, my knowledge is generalized.

It's always best to get a 2nd (and 3rd) opinion.

BTW -- did you mean to say your engine temp never drops below 180*F?

[sajohnson]

Originally Posted by Tobbun

So those of us in Hot Texas don’t really need to worry about idle? Is there a recommendation on engine temp that the high idle or trucker stick is trying to keep the engine at?
It is amazing how quick the temp rises inside the cabin once the air goes off at pitstops.

Near as I've been able to tell from all the reading and research I've done, the primary concern is that the engine coolant temp remain in the normal range.

IIRC, when just cruising with no load, the ScanGauge in our rig shows about 190*F (188-192). I've seen it as high as 220*F after a long climb.

We have the Espar engine coolant heater. FWIW, I believe it shuts off when the coolant temp reaches 185*F and turns back on at 167*F. That's something I read, not something I measured, but it seems about right.

I found this. It is for the previous diesel engine in the T1N chassis, but I do not believe it has changed. I know the 250*F upper limit is the same:

"The OEM scaling is 35F for the divisions. 180F is marked. 250F is marked. The mid mark is 215F. 1/2 way between the 180F and the unlabeled 215F is 197.5 (180 + 17.5) or 200F. 195F thermostat as designed."

https://sprinter-source.com/forum/sh...ad.php?t=47965

I'd say at least 180*F, with 190-200*F being better.

[Mr. B]

Originally Posted by sajohnson

Hey Yaroslav,

Don't make the mistake of assuming I know what I'm talking about.

In all seriousness, I try very hard to post accurate information, but while I'm a technician, my knowledge is generalized.

It's always best to get a 2nd (and 3rd) opinion.

BTW -- did you mean to say your engine temp never drops below 180*F?

When hot I am idling for unlimited time to run the vehicles A/C.
And yes, I meant 80 degrees Celsius because my data is set up for it. (though you’re correct it’s about 180 Fahrenheit).

[Mr. B]

Originally Posted by wachuko

Correct. Only air filter.

Thanks buddy. Btw where’re you in Orlando? Let’s meet some day.

[sajohnson]

Originally Posted by Mr. B

When hot I am idling for unlimited time to run the vehicles A/C.
And yes, I meant 80 degrees Celsius because my data is set up for it. (though you’re correct it’s about 180 Fahrenheit).

You should be in good shape, especially since you take long trips fairly often. The more highway driving the better.

Just curious, what do you use to measure the engine temp?

FYI -- years ago, before we bought our View, I asked 2 Sprinter shop managers if there were any guidelines regarding idling. They both said no. Both said that many of their clients were contractors who sometimes idled their Sprinter vans all day long while on the job. Many of them had hundreds of thousands of miles on their vans and had no problems related to idling. They both seemed surprised by the question and said it had never come up before.

One of them, the shop manager at Sun Motors in Mechanicsburg, PA (home of "SprinterFest East") was curious enough that he asked MB USA. The people at MB USA did not know(!) so they supposedly asked MB Germany.

The answer that came back was:

* Up to 1 hour without the "high idle kit"
* 1-1/2 to 2 hours with the high idle kit

I have to wonder if someone didn't just pull that out of their ear, because:

1) It was verbal only, nothing in writing. I've never seen anything in writing -- and MB is anal about everything: fuel quality (% biodiesel); oil -- type and MB approval, etc.
2) It was (supposedly) relayed from MB Germany to MB USA, and then to the shop manager. The message may not have been conveyed accurately.
3) It seems highly unlikely that customers would pay $1,800 for the high idle kit if it only increases the idle time by 1/2 hour to an hour.
4) There was no mention of engine temp or ambient temp -- and those are clearly huge factors.
5) It is all but pointless to give an idle time without any reference to temperature. They would have to assume the absolute worst possible scenario.
6) Sprinters are used as emergency vehicles and are routinely left idling for hours.

As I've said elsewhere, there is a HUGE difference between starting a Sprinter on a February morning in Fargo, ND when the temp is -30*F (-34*C ;-)) and then letting it idle for 2 hours at normal speed with no load, and pulling off of the Interstate on a 105*F day in Arizona and letting the engine idle for a couple hours in a rest area running the A/C.

Still, I figured I'd pass that info along.

[Vlamgat]

Originally Posted by J. Morgan

In theory you can run an 11,500 air conditioner from an inverter, and you can for a time, minutes, but in practice, even with a strong charging source, it’s just too much.

I’ve tried it,,,,, the inverter will go south and quick, I’m about sure that the high amp charging was WAY too inconsistent for the devise to survive. Save the money and frustration, make your generator better instead.

(I was running a 5,000 watt inverter that I purchased to run the air conditioner, and charging with 300 amp capacity alternators. )

I had the same experience. The other thing is that these ratings are for New, Factory a/c units. In the field there are variations and after a year or 2 the current demand for start up increases. My 11,500 Dometic and another Danhard started drawing 2900 watts at start and are now up to 3600 after 4 years. about 2 years ago a single Honda was insufficient to run either using a 3000/6000 watt inverter. So CAVEAT EMPTOR.

[sajohnson]

Originally Posted by Vlamgat

I had the same experience. The other thing is that these ratings are for New, Factory a/c units. In the field there are variations and after a year or 2 the current demand for start up increases. My 11,500 Dometic and another Danhard started drawing 2900 watts at start and are now up to 3600 after 4 years. about 2 years ago a single Honda was insufficient to run either using a 3000/6000 watt inverter. So CAVEAT EMPTOR.

That's interesting about the increasing start-up demand over time. I'd never heard that before.

So each of the A/C units began to take 2900W to start, and then each began to take 3600W? It's odd that they would be identical (being different brands).

You mentioned a Honda generator and a 3000/6000 watt inverter. Were you using the Honda to charge the batteries that were feeding the inverter?

[Mr. B]

“Just curious, what do you use to measure the engine temp?”

- Temperature of engine coolant. One time pressing of the left up arrow button on the steering wheel )))

[sajohnson]

Originally Posted by Mr. B

“Just curious, what do you use to measure the engine temp?”

- Temperature of engine coolant. One time pressing of the left up arrow button on the steering wheel )))

The early model (T1N) Sprinters have a dash gauge, but our 2008 NCV3 has no way to determine engine temp -- no gauge or readout. In fact, no fancy buttons on the steering wheel.

IDK if this is still the case but back then the Mercedes' "Cross Wind Assist" feature was not even an option on the cab-chassis.

Many owners of the earlier NCV3 use a ScanGauge II or similar OBD II device to measure engine coolant temp. The ScanGauge is nice because it can be programmed to display: coolant temp; trans fluid (ATF) temp; voltage; engine load; boost pressure; intake air temp, etc (any 4), as well as calculating instant and average mpg.

It is a neat little device, but not as useful on newer Sprinters -- although ATF temp is nice to know.

[Vlamgat]

The numbers are not exact but OOM and varied from Start sequence according to ambient. For example both would start at 80 ambient at 10 am after an all night recharge. However if the start was at 4 pm and 90 ambient, even after an all day temperature controlled charge, the inverter would get the a/c running drawing 2900 and even occasionally 3100 watts but the generator at high speed could not sustain it. When 2 Hondas are connected in parallel, both a/c units will run at draws that vary from 3100 down to 1800. The video install on the Micro Air site shows that actual momentary draws from a Dometic can hit 4200 watts. The Easy Start reduces this to 1400. I have one of these for my Dometic but my wiring is nothing like the instructions which means that I will have to the install with the help of their customer service which will need an open afternoon on a work day. Something I don't have for now.

As for the Danhard, it's now 12 years old and needs both Hondas. Easy Start has never been installed on these so I am stuck for now unless I replace it.

[Mr. B]

Hello Gentlemen
Decided to refresh the topic.
Do you think a small external Honda EU2200i gen will run our roof AC ?

[gmillerok1]

Originally Posted by Mr. B

Hello Gentlemen
Decided to refresh the topic.
Do you think a small external Honda EU2200i gen will run our roof AC ?

The rating for the Honda 2200i is 15 amps according to the specifications in the manual at page 74. The Dometic specs show it will draw 15.76 amps (and that's likely the maximum draw at the highest ambient temperatures, and is not the surge draw that is over 50 amps. So you would definitely need the Softstart kit to be able to use it.

In theory, sticking to the numbers, the answer is no.

But, it's a bit more complicated. Is the rating by Honda conservative as it's less than one amp more than the specified rating? Is the rating for the Dometic accurate? In the real world, the amount of amp draw is dependant on the ambient temperature. At max cooling it will draw likely the rated amperage of close to16 amps. In cooler weather, that may drop to 14, and if the fan is in low mode, even less.

Dometic recommends a 3.5kw rated genset, but the 2800 watt genset runs it without issue (but a Softstart is recommended).

About the only way to be absolutely sure is to try it and see. But if you want a definite yes or no without trying it based on the ratings, then no, it won't.

[Al and Missy]

Get an EasyStart. I have one and my eU2000i runs my 15,000 BTU on it. Typical soft starts are just a different starting capacitor. The EasyStart is a microprocessor controlled unit that learns your compressor's characteristics and starts it slowly after it starts the fan. It also detects over current and undervoltage, and maybe some other stuff and shuts off to protect your AC unit.

Use the blue search box at the top of the page and search EasyStart.

Al

[gmillerok1]

Originally Posted by Al and Missy

Get an EasyStart. I have one and my eU2000i runs my 15,000 BTU on it. Typical soft starts are just a different starting capacitor. The EasyStart is a microprocessor controlled unit that learns your compressor's characteristics and starts it slowly after it starts the fan. It also detects over current and undervoltage, and maybe some other stuff and shuts off to protect your AC unit.

Use the blue search box at the top of the page and search EasyStart.

Al

I had meant to refer to the Easystart, but I was too late to edit it. Yes, that is definitely the one to get.

[Mcrid]

Originally Posted by gmillerok1

T but the 2800 watt genset runs it without issue (

.

According the Cummins Onan Spec sheet. The LP Genset is only 2500 Watts with a continuous 20.8 Amps and a 21 Amp breaker.

[gmillerok1]

Originally Posted by Mcrider

.

According the Cummins Onan Spec sheet. The LP Genset is only 2500 Watts with a continuous 20.8 Amps and a 21 Amp breaker.

Correct. I stand corrected.

[Mr. B]

Thank you everyone replied, I will search it.
Happy New Year ��

[Mr. B]

Just reviewed the suggested topics, and Honda 2200 gen with EasyStart 364 should do my 1300BTU AC on overnight parking.

However, this is another thing of using it I would like to discuss with you guys.

Since the stock propane Onan genset is well designed in the system of power distribution, I wish to leave it as is for the factory designed purposes, and to have a portable Honda just for a no-noise overnight cooling.

Can I simply put a Honda genset on the ground and put it temporarily into the RV shore power inlet? Would it work when I park overnight? If yes, then would a permanently installed EasyStart interferes with the stock system when I use the factory installed Onan genset?

[GMFL]

Yes, the Honda can power you unit through the shore umbilical. The easy start 364 will not effect any of the Normal operation other than decrease the amps required to start the unit.

[LewK]

I installed the easy start and converted a Honda 2200 to propane. I use the standard shore power cord and an extended propane line connected from the exterior propane port to the Honda which is placed behind a front wheel and secured with a bicycle lock.
With the gen set running, windows and doors closed you can barely hear the Honda inside.
So far this has worked perfectly for overnight stops with a/c, and fridge running