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Foretravel Motorhome Forums => Foretravel Discussions => Topic started by: Old phart phred on September 19, 2017, 10:08:35 pm

Title: New a/c unit
Post by: Old phart phred on September 19, 2017, 10:08:35 pm
New Coleman mach 3 power saver arrived today to replace my original 89 unit in the front that died. I bought Coleman to help protect my city of Wichita, and my property values, as the factory is only a couple of miles from my house. I will report back once I get it installed. I will drive the coach to work and have a forklift to get units transferred. Is one hour enough time to swap the roof unit only? Just 4 bolts and wiring swap, and new gasket.
Title: Re: New a/c unit
Post by: DavidS on September 20, 2017, 01:02:08 am
Depends on how fast you work. 1 to 1.5 by yourself .. have all the tools ready ^.^d  .. eagerly awaiting the tests
Title: Re: New a/c unit
Post by: Old phart phred on September 20, 2017, 02:15:43 am
My goal was to be able to run down the road with the dash a/c running, and one rooftop unit off the alternator via the inverter.
Title: Re: New a/c unit
Post by: nitehawk on September 20, 2017, 07:24:41 am
Inside ceiling control panel won't match the old '89. How do I know? Previous owner replaced with the Mach 3 (or 2?) and because the vinyl center strip on the ceiling didn't make it to the panel, they added a white blank outlet cover.
Not real pretty but does the job,and I haven't found anything to replace it. Maybe a piece of vinyl cut out of the inside of one of the cabinets?
Title: Re: New a/c unit
Post by: wolfe10 on September 20, 2017, 09:02:20 am
My goal was to be able to run down the road with the dash a/c running, and one rooftop unit off the alternator via the inverter.

What size alternator and wiring from there to battery and what isolator are you using?

What is amp draw @ 12 VDC to run the roof A/C?
Title: Re: New a/c unit
Post by: jcus on September 20, 2017, 09:23:52 am
You will need a least a 2500 watt inverter, a pretty big battery bank and at least a 200 amp alternator, none of which came standard with your coach to run a roof ac while travelling.
Title: Re: New a/c unit
Post by: Old phart phred on September 20, 2017, 10:04:25 am
Power saver 1075 watts standard conditions, 1320 watts desert so about 125 amps of 12v. Have not bought alternator or invertor yet. Looking at a 3kw multi stage inverter that only draws 0.55 amps when idle. And maybe a Delco 28si alternator. New Isolater is rated for 200 amps continuous. Cable is a mix and up for further review.
Title: Re: New a/c unit
Post by: craneman on September 20, 2017, 09:03:53 pm
What 3K inverter only uses .55 amps at idle?
Title: Re: New a/c unit
Post by: Old phart phred on September 20, 2017, 09:17:32 pm
Samlex and cotek, I believe I spelled them correctly but that info is at work. Multistage or stacked maybe is how they achieve it or lie idk. Bay marine has samlex I believe, they may know. Cotek is a spitting image of samlex unit and specs appear identical, for about $200 less. Still looking cause I can buy a good bit of propane, for that kind of money, just can't brag about it. Modern well cooled alternator may be a no brainier.
Title: Re: New a/c unit
Post by: jcus on September 20, 2017, 10:30:20 pm
Samlex and cotek, I believe I spelled them correctly but that info is at work. Multistage or stacked maybe is how they achieve it or lie idk. Bay marine has samlex I believe, they may know. Cotek is a spitting image of samlex unit and specs appear identical, for about $200 less. Still looking cause I can buy a good bit of propane, for that kind of money, just can't brag about it. Modern well cooled alternator may be a no brainier.
Do not think it is possible. .55 watts is barely one small led on the display. 55 watts is more realistic.
Title: Re: New a/c unit
Post by: Tim Fiedler on September 20, 2017, 10:39:13 pm
Prisoners 3000 best in class @ 17 amps
Title: Re: New a/c unit
Post by: Old phart phred on September 20, 2017, 11:38:37 pm
May be new tech or maybe lies involved, I really can't say for sure. Maybe they are indeed stacked and activate as required. there are lots of Cascade systems out there that function the same way.
Title: Re: New a/c unit
Post by: Dwayne on September 21, 2017, 03:07:13 pm
I have the Mach 3 power saver.  I hate the new refrigerant.  It doesn't seem to remove enough moisture from the air so while cool it is a sticky cool rather than a dry cool. 
Title: Re: New a/c unit
Post by: lgshoup on September 21, 2017, 04:05:49 pm
Refrigerant type would have nothing to with the moisture removal as long as the unit reaches the desired coolness. Cold is cold. Maybe not on long enough or often enough. I'd check out the thermostat to see that it's turning on and off when sensing the house temp.
Title: Re: New a/c unit
Post by: Old phart phred on September 21, 2017, 05:08:53 pm
Depending on how they achieve the efficiency, the amount of coil surface below dew point temperature effects the moisture removal. Running the fan on low will lower these temps
Title: Re: New a/c unit
Post by: Caflashbob on September 21, 2017, 06:29:59 pm
There used to be dedicated 110 volt alternator systems available, 4000 watt.  Separate alternator.

Some rememberance of constant speed?  Alternator and a inverter? box?

Lots of power generated driven through a belt.

Try fabco
Title: Re: New a/c unit
Post by: Old phart phred on September 24, 2017, 12:23:02 am
Finished intall today, used exotic Chinese Luan with custom 5.2 mm edge trim to match Corian countertop motif. About .013 coach bucks.
Title: Re: New a/c unit
Post by: nitehawk on September 24, 2017, 07:44:06 am
I take it the new unit has a smaller footprint than the old one? Center vinyl doesn't reach the new inside control unit? Nice solution to the problem.
Did you find the yellow foam/glue holding the vinyl up has deteriorated and is now nothing but sticky crumbs?
The adhesive & foam had gotten so bad that the vinyl was hanging down in our coach. I had to remove the center strip, remove a million staples, vacuum out the headliner, wipe out what I could, spray adhesive up in there, then pull the vinyl towards the center of the coach and restaple everything. Got new snaps with the upholstered cover buttons from FOT and added another row front to back between the cabinets and the center strip. Took the center strip apart, cleaned it up, glued on new 1/2" thick foam (made sure the screw holes on the vinyl lined up with the holes in the luan board) and then put the center, now padded, cover back up in place. WHEW!!
Title: Re: New a/c unit
Post by: Old phart phred on September 24, 2017, 08:56:07 am
New ceiling unit left a 4" gap on the aft end, and a couple of inches on each side of discolored headliner. Yes my headliner has sags and needs replaced.
Title: Re: New a/c unit
Post by: Old phart phred on September 24, 2017, 04:52:02 pm
Refrigerant type would have nothing to with the moisture removal as long as the unit reaches the desired coolness. Cold is cold. Maybe not on long enough or often enough. I'd check out the thermostat to see that it's turning on and off when sensing the house temp.
My sensor was in a terrible location with cold air leaking from supply to return plenum directly on to the sensor wire and short cycling the unit. Working to seal those leaks up with duct tape. When I was on the roof I also duct taped all of the evaporator housing joints. If I would of had some spare armaflex I would have did the suction piping that is in the 120* airstream. Unit is noisy with turbulent supply air system to ceiling grille, compressor noise is not dominant. Control knobs in my ored are at 72" above the floor, so a head banger for some.