I made the basement A/C extractable...

[Jim_HiTek]

Excellent mod.

I don't weld so mod's to the RV frame to allow sliding the AC out won't work for me but I appreciate fine workmanship displayed above.

What I did though was to lube and cover the 2 large lowering bolts, drop the frame using those and then a lever helps extract the AC onto a simple platform of two 5 gallon buckets under a 12" wide 2" board, 4 feet long. Nice and stable and the perfect height to set the AC on.

Since mine lasted 19 years before needing maintenance, I thought I'd be safe from having to do it again after I installed a brand new Coleman last summer. Oh how wrong I was as the new Coleman has failed already. Three year warranty, but still a hassle. Your mod would have come in handy for sure.

I do have a question...and I'm not a HVAC tech...is there really a reason to insulate all those tubes? What advantage is there to doing that? Thanks.

 

[Tony65]

Excellent mod.

I don't weld so mod's to the RV frame to allow sliding the AC out won't work for me but I appreciate fine workmanship displayed above.

What I did though was to lube and cover the 2 large lowering bolts, drop the frame using those and then a lever helps extract the AC onto a simple platform of two 5 gallon buckets under a 12" wide 2" board, 4 feet long. Nice and stable and the perfect height to set the AC on.

Since mine lasted 19 years before needing maintenance, I thought I'd be safe from having to do it again after I installed a brand new Coleman last summer. Oh how wrong I was as the new Coleman has failed already. Three year warranty, but still a hassle. Your mod would have come in handy for sure.

I do have a question...and I'm not a HVAC tech...is there really a reason to insulate all those tubes? What advantage is there to doing that? Thanks.

Hi! The reason seems obvious to me.

The refrigerant passes through those pipes at very low temperatures and it is best that it remains as cold as possible until it reaches the radiator. Thermal insulation in all air conditioning systems is essential, also for energy saving.

I'm so surprised that Coleman-Mach didn't do this in the factory, and this for what? Save a few dollars? What does it mean? Make me spend 10/20 dollars more but do a job well done!

One question: have you ever used the Supco SPP4E? Can you tell me how to install it in a Coleman-Mach 6535-871?

It is not clear to me whether the 6535-871 is a PSC or CSIR unit.

By the way... Your blog was very useful to me in doing maintenance work. Congratulations for the beautiful contribution you have given everyone.

 

[Jim_HiTek]

Hi! The reason seems obvious to me.

The refrigerant passes through those pipes at very low temperatures and it is best that it remains as cold as possible until it reaches the radiator. Thermal insulation in all air conditioning systems is essential, also for energy saving.

I'm so surprised that Coleman-Mach didn't do this in the factory, and this for what? Save a few dollars? What does it mean? Make me spend 10/20 dollars more but do a job well done!

One question: have you ever used the Supco SPP4E? Can you tell me how to install it in a Coleman-Mach 6535-871?

It is not clear to me whether the 6535-871 is a PSC or CSIR unit.

By the way... Your blog was very useful to me in doing maintenance work. Congratulations for the beautiful contribution you have given everyone.

I didn't use the Supco as that part is basically generic with lots of manufacturers so I went with the low priced model as it's easily accessible for maintenance...and wouldn't need to be changed very often. I believe this is the one I used: Cap...

My thought was that the engineers were well aware of thermal needs of the system so I decided not to add insulation trusting in their judgement. Having worked at Hyster for years in engineering I have a trust of engineers in other fields. But I'm aware that sometimes that's a misplaced trust.

I don't know if your discontinued model is a PSC or CSIR unit but there is this from Google:

"CSIR have more starting torque and are cheaper, CSCR run smoother, less pulsating torque and slightly better efficiency. PSC are cheaper yet and no moving parts, but have less starting torque, so are mostly used for centrifugal pumps and fans where that's not needed. Feb 15, 2024"

I'm a bit confused about my parts list because I thought I bought 'slow start' capacitors for the compressors but googleing the part values take me to 'hard start' caps. I'll have to look into that. Could I have made a mistake telling people that the Coleman's come with soft start???? Because that's what I thought I bought.

Thanks for the kind words. I try to make my articles as complete and concise as possible but errors do creep in.

 

[RayIN]

JimHytek the RVP basement compressors(made by ColemanMach) come with hard-start PTCR on the start caps.

 

[Jim_HiTek]

Well, I'm not sure Coleman makes any compressors...this is in several of their models:

6 - Panasonic Compressor(s)
7 - Sanyo Compressor(s)
8 - Tecumseh Compressor(s)

My old Coleman was an -871 so Tecumseh.
My new Coleman is a -611 so a Panasonic.

Thx for the other info.

 

[RayIN]

Well, I'm not sure Coleman makes any compressors...this is in several of their models:

6 - Panasonic Compressor(s)
7 - Sanyo Compressor(s)
8 - Tecumseh Compressor(s)

My old Coleman was an -871 so Tecumseh.
My new Coleman is a -611 so a Panasonic.

Thx for the other info.

Good catch Jim. That was confusing language, I meant the entire unit is made by Coleman Mach. BTW, I think the Panasonic compressors are better.

 

[Tony65]

JimHytek the RVP basement compressors(made by ColemanMach) come with hard-start PTCR on the start caps.

OK, but my doubt is another, my Coleman-Mach it's a PSC unit or CSIR?

The distinction is fundamental to understand how the Supco SPP4E should be installed.

 

[Tony65]

I didn't use the Supco as that part is basically generic with lots of manufacturers so I went with the low priced model as it's easily accessible for maintenance...and wouldn't need to be changed very often. I believe this is the one I used: Cap...

My thought was that the engineers were well aware of thermal needs of the system so I decided not to add insulation trusting in their judgement. Having worked at Hyster for years in engineering I have a trust of engineers in other fields. But I'm aware that sometimes that's a misplaced trust.

I don't know if your discontinued model is a PSC or CSIR unit but there is this from Google:

"CSIR have more starting torque and are cheaper, CSCR run smoother, less pulsating torque and slightly better efficiency. PSC are cheaper yet and no moving parts, but have less starting torque, so are mostly used for centrifugal pumps and fans where that's not needed. Feb 15, 2024"

I'm a bit confused about my parts list because I thought I bought 'slow start' capacitors for the compressors but googleing the part values take me to 'hard start' caps. I'll have to look into that. Could I have made a mistake telling people that the Coleman's come with soft start???? Because that's what I thought I bought.

Thanks for the kind words. I try to make my articles as complete and concise as possible but errors do creep in.

Listen, the work of people like you is invaluable, manufacturers' manuals are often poorly written and incomprehensible, while blogs like yours explain everything in detail. Many people can understand things better thanks to people like you.

I myself thought about doing maintenance on my air conditioner only after reading your guide, otherwise I wouldn't even have any idea where to start.

Speaking of air conditioner maintenance... Now that I saw what was inside after 24 years I was scared... Dust, mould, rust and who knows how many other things... All stuff that ends up in our lungs every time we Let's turn on an old air conditioner. We must consider ourselves lucky if we have not contracted diseases such as "legionellosis" or pneumonia.

I am of the opinion that taking out the air conditioner at least once a year and giving it a clean and a good disinfection is a guarantee of health and well-being. That's why I'm glad I put it on the sliding rails.

I was also thinking of installing a small ultraviolet lamp inside, so that when you turn it on the ultraviolets keep it disinfected.

 

[Jim_HiTek]

Sorry, Tony65, I'm not conversant about those designations. When I installed the new start/motor caps, I just transferred the wires from the old to the new in the same orientation. Since they are AC devices, polarity wasn't a concern, just the voltage and capacitance. I had copied the capacitance value and voltage off of each cap leaving them in place, then googled those designations. All of those caps are standard motor start or run caps and readily available from numerous vendors. I didn't dig deeper into what they're designated as (the PSC or CSIR) because it wasn't necessary as the replacements I ordered were called "direct replacement" or similar or actually called out for a Coleman Mach 2-ton AC. And later I found the p/n's for those caps in an Airxcel drawing as a back check.

Here's a link to a bunch of drawings for the various motor/compressor/cap combos: What is the full form of CSIR...

@Ray,IN: As far as the -611 designation goes, the '6' does stand for Panasonic and is called an 'Efficiency' compressor. In my tests, those compressors ran on reduced current. I believe it was 6 amp LOWER then the Tecumseh compressors for each one. And I think it was 24 amp for the both of them to be running, which means if most everything else in the RV was off, the Power Center might allow the 2nd compress to run. Going by memory though, YMMV.

 

[Jim_HiTek]

Listen, the work of people like you is invaluable, manufacturers' manuals are often poorly written and incomprehensible, while blogs like yours explain everything in detail. Many people can understand things better thanks to people like you.

I myself thought about doing maintenance on my air conditioner only after reading your guide, otherwise I wouldn't even have any idea where to start.

Speaking of air conditioner maintenance... Now that I saw what was inside after 24 years I was scared... Dust, mould, rust and who knows how many other things... All stuff that ends up in our lungs every time we Let's turn on an old air conditioner. We must consider ourselves lucky if we have not contracted diseases such as "legionellosis" or pneumonia.

I am of the opinion that taking out the air conditioner at least once a year and giving it a clean and a good disinfection is a guarantee of health and well-being. That's why I'm glad I put it on the sliding rails.

I was also thinking of installing a small ultraviolet lamp inside, so that when you turn it on the ultraviolets keep it disinfected.

Thank you! Nice of you to say. And your work on that tray setup is top notch.

Of course, factory workers might not always do a good job but when I pulled out my 19 year old Coleman, there was little in the way of mold, none actually, or even dirt inside the "Inside Air" cavity. A bit of rust on the floor which I treated. Not much dust and zero debris in the plastic duct work that sucks air from inside, cools it and then sends it up the formed duct work, even though the connection on the side of the AC unit had partially failed insulating foam tape. I did have some rust on the outside of the AC too, treated that. And removed and discarded the duck bill drain device that wasn't pliable any longer so it would drain better.

If you checked the pictures of my RV's duct work, here at Misc Heating and Cooling (scroll down as it's under the article about installing temporary window ACs), you'll see how clean my duct work is. But I change my filter every quarter and I don't think the PO used the RV other than as a snow bird transportation, living in S&B places when they arrived.

Of course it would all depend on the type of humidity you spend most of your time in. Like the desert SW would be much dryer and less prone to mold than Florida.

Anyway, thanks for you thoughts! I didn't see any mold in mine so really didn't consider it.

 

[Duner-WO]

......
Next step: replacing lead-acid batteries with LiFePO4 batteries.

Tony, you are one ambitious (and clever) guy/engineer! I'm jealous I wasn't part of this hi IQ discussion last month. But I have a hard time visualizing driving that big rig in Europe. And where do you camp that big rig? Two years ago my wife and I were on a pilgrimage in France, Spain, and Portugal. Nearly all of the tour was in a new 45 ft Mercedes bus. The expressways were very nice easy going, but in the villages, towns and cities sometimes the going was chilling and I was impressed with the skill of the driver.

Regarding lithium batteries: Last fall I installed a Battle Born system with a Victron 3k Multiplus II inverter/charger. What a sweet piece of design and functionality compared to the 2K Dimensions. I see it on Amazon for just $1114 here in USA. I bought a pair of Battle Born 270 Ah batteries. But I see the Epoch 460ah battery for a lot less money and both have 10 yr warranty.

Back to topic:
Two years ago the start/run cap for the ODBM went out while on a short July trip to Phoenix (as in HOT). When I got home, I pulled the unit to replace the cap, and while I had the unit out I noticed the amp draw was up around 26 or 27 amps .... about 3-5 amps too high. After about 20-30 minutes I noticed the IDBM was running very hot. I replaced that start/run cap, no change. So I searched for a replacement motor and could only find ones for $600-700 and not available. So I made a decision to replace it with a readily available Fasco motor, same form, fit and function, but with a shorter shaft that wouldn't use the pillow bearing. Installed the new motor and dang, the amp draw was still too high and running hot.

What I found, blew my mind. If I imposed just a little back pressure at the outlet of the cold air, the amp draw dropped to normal the the motor ran cool.
This seemed so counterintuitive and shows how little I remember from my college days on induction motors. Hopefully someone here can explain the theory behind this phenomena. Well after 2 years the stubby shaft motor is still running fine. I couldn't go back and use the original motor, because I had to destroy the shaft to get the frozen squirrel cage off (Murphy's 1st law).

I made a 3000 mile trip to see the total eclipse this past April in the Texas Hill Country. Then north of Houston it got a little warm and a lot humid. My basement A/C was struggling to keep up with only 88 deg outside. One side is frosting up, the other is not. So I think one side needs recharging. Back to pulling the unit and getting a mobile repair guy out. Oh what fun.

Happy Trails,
Bill

 

[Jim_HiTek]

UPDATE:

I've pulled my 1 year old Coleman Mach and found that they are still using those 100 year old design pillow block bearings with fiber packing that's supposed to be oiled once per year though you'll not find instructions to do that in the Coleman Maintenance manual. It only states this: "In fact, the only maintenance that must be taken care of on a regular basis is the cleaning or replacement of the units return air filters."

What I've found is that either the bearing manufacturer or Airxcel neglected to put any oil into the shaft bearings...there's an oiler tube with spring operated lid on them, and it was dry on my new ODBM. The bearing ran dry, began to drag, that caused the motor to slow and eventually (it appears, still testing) burn the motor coils due to stalling. Why they're not using ball bearing pillow block bearings is answered by the retail price...for the plain oiler type bearings, ~$12 in single quantities. And $35 for ball bearing types.

I was able to oil the motor bushings on my 19 yo Mach which helped get several more years of service from the motors but this new Mach doesn't have oiling tubes on the motor shafts. I haven't discovered if those bearings are ball bearing or not yet but I doubt it.

 

[Tony65]

Eh... I would like to be an aerospace engineer... When I was a child, in the 60s we were convinced that our future would be in space. Then the politicians and bankers with their wars and their business stole our future.

So I'm content with being a radio amateur who fiddles a bit with electricity.

Actually driving in Europe is not always easy and I assure you that several times I found myself in a cold sweat carrying my 38 footer around, even in small Italian towns.

However, you can also see some beautiful places and when you get there you forget the effort you put in to get there.

Unfortunately we and our RVs are victims of the neoliberalism that prevails today: maximum profit, minimum cost. This policy is ruining our lives.

But - I say - if I'm willing to spend $200,000 to buy an RV, let me spend $500 more but do the job the way it needs to be done. For example, use stainless steel where possible. I won't go broke on $500 but I'll waste a huge amount of time and money repairing a rust damaged windshield.

However, now I am attaching photos of some places I have visited, so that you will want to come with your RV to Europe.

By the way, the photos of the beaches you see are real, open to everyone for free and - above all - you don't have to worry about sharks and other beasts that don't exist here.




In order from top to bottom:

Little sardinian town. My RV is bigger than many houses...
Orvieto town.
Viterbo town, Palace of the Popes.
Spoleto town.
Livorno harbour, the biggest ferry in the world. Slightly smaller than the Titanic, it sails the Italy-Sardinia route.
Lourdes, France.
Dolomiti Mountain, Italy.
Avila town, Spain.
The Pink beach, Sardinia, Italy.
A beach in north Sardinia, miles and miles of clear and hot water... No sharks or other problems...