Installing Soft Start in Dometic AC

[ReagentGrade]

Please don't PM your photos. I want to see them too!

[Parker]

Originally Posted by ReagentGrade

Please don't PM your photos. I want to see them too!

Okay. I'll be happy to post everything tomorrow.

[Parker]

Okay, here goes with the EasyStart installation. Before doing anything, I disconnected AC power. Next, I removed the four large-headed screws around the perimeter of the upper cover and set the cover aside on the roof. Everything else is done from the curb side.

The top photo is the junction box where everything happens. Note the schematic on the cover, which is extremely helpful. I had to do some judicious cutting of the foam material to get the cover off. Inside is the run capacitor on the right, a start capacitor in the bottom, and a gizmo on the left called a Positive Temperature Control Relay that's part of the original start circuit. Both of these are removed. Also, there was a screw sticking into the work space on the left side that I removed. On the bottom is a view after all connections are made. I took more photos just to help keep track of things along the way.

Just some observations...the EasyStart instructions are clear enough after a little study and time required to identify which wires are involved. Hint: the compressor is on the driver's side. It's the cylindrical component about the size of a loaf of bread. A group of three wires, red, white, and blue in my case, crosses over to it. The blue one is the one that's tee'd into from the EasyStart. That's the bolted connection in the photo. I would like to have had a three-way crimp connector for this, but couldn't find one. Otherwise, it's just a matter of going step-by-step and reassembling in reverse order.

The instructions call for starting the air conditioner on a standard (non-generator) circuit five times before connecting to a generator. This allows the EasyStart to "learn" the starting characteristics of the AC. When I first connected to the generator, I had eco mode off, started with the AC fan on low, and had the battery switch off to avoid charging loads. After a few compressor cycles, I switched to eco mode and kept adding loads until the fan was on high and I had a moderate charging load into the battery. Not once did the generator stumble.

I'm not really a big fan of generators, but sometimes they make a difference for us whether or not we're willing to try a warm weather spot with no hookups. At least now it looks like we can get by with a reasonably small generator that will even run in eco mode.

Any questions, please ask!

Parker

[Jubal]

Parker
Thank you for sharing. Very well done !
Which 364 model variant did you use ?
https://www.microair.net/products/ea...nt=30176048267

[gyuill]

I have been looking at the electronic devices to help run an AC unit on a small generator. Not the hard start capacitor but the "Smart Start" by Dometic and the "Easy Start " by Microair.
In my search I came across a discussion on the fiberglass forum of the Microair 364 and the mention of a discount code of "CASITA" for $50 off the listed price of $299. I went to the MIcroair site and ordered the 364 model and got $40 off with that code.
I am not pushing this product and don't know if it is any better than the Dometic product.
I did have a Casita at one time!
Graham

[Parker]

I did exactly the same thing, with the same rationalization!

[rbryan4]

If the online reviews are any indication, the MicroAir is much better than the Dometic smart start kit.

By the way, you can also get the board only without the umbilical wires and the enclosure for substantially less. You'd just have to run your own wire, making it a little more complex install.

[Parker]

I have been extremely impressed with mine, and it wasn't that hard to install.

[cpaharley2008]

I read somewhere that the units with the soft start installed operate more quietly while on 120V plugged in? In other words, disregarding the generator option, if installed the on/off cycles are not as noisy? Anyone else aware of this side benefit?

[Parker]

That's interesting. I don't have enough experience with it yet to comment on overall noise level (which I wouldn't expect to change) but the compressor does come up gradually which seems to alleviate some of the noise at that point. Maybe the gradual increase in load gives some illusion of overall noise reduction.

[cpaharley2008]

Yes, something about the "thunk" at start up is not as loud??

[Parker]

Yep. No more thunk.

[gyuill]

I did what Parked did and the results were great. With the standard AC on my 2012 19' the 2000 watt Briggs and Stratton would overload every time. The AC was pulling 9 amps after startup on standard power. After installing the Easy Start the generator would very smoothly start the AC every time. ( I had the breaker off for the battery charger) With the AC running I turned the battery charger breaker on and the surge tripped the generator. I then stared the battery charger first and then turned the AC on and it worked fine.

Graham

[Parker]

Hey Graham, you're keeping me up too late! I'm not surprised that the extra load from the charging could trip the generator. I think the plan has to be to be sure the battery is topped up (charge current back down to maintenance level) after starting the generator, then cranking up the air conditioner. Congratulations on your installation!

Parker

[gyuill]

Thank you for the photos and description of your install, it made things easier. The batteries were topped up when I turned the converter breaker on and the generator was able to handle the converter being turned on without the AC running. I think the converter initial inrush current was too much for the generator with the AC running. Guess we need an Easy Start for the converter too.

[Parker]

Hmm. Interesting. Our AC runs 13-14 amps and still handles the converter being on at a maintenance charge level, but it well could be an inrush event that's tripping your generator as you suggest. I assume that after you have your converter on and charging at a reasonable level, you can start up your AC and have both going simultaneously. That's the case here at least. I was really happy to see it would handle this combined load while running in eco mode and then accelerate up as the load required.

[Kent]

No more hard thunk!

Honda 2000 runs AC without issue.

Money well spent.

[padlin]

Gotta get me a carport and step ladder like yours, nice job.

[Parker]

Well done!

[elongest]

My H2Ki would run my A/C around sea level with no real issues( Not in ECO mode). I made a recent trip in the mountains in 90 deg. + temps. The Honda struggled quite a bit. After that trip it was order a H2.2Ki or order the Easy Start kit. I just ordered the Easy Start kit. I hope it also gets rid of the clunk. Parker thanks for the greats posts on the install.
Eddie