I have not closed up my unit as yet . Or tried to operate it .
I have not replaced the indoor blower as yet .
Im now considering replacing the 2 relays also .
I will get the info off the start kit in the day time for you
Here is what I have at present , note item 43 of RVP
Journey Cat: Thanks for posting the AirXcel Part# 8333A9021 instructions that clearly they consider this part a "Hard Start Kit."
Can you measure the Capacitance and let us know that value?
These Start Capacitors do not seem to list their uF values, but I did find one RV Distributor's who sells the AirXcel Part# 8333A9021 and in the website description they show the capacitance is supposed to measure between 88uF - 108uF. So if you can verify this that would be great!
NOTES:
* The P.T.C.R. is a thermistor and operates like a dropout-switch, so maybe the capacitance value is not that important?
* It would appear all 65xx Series Basement ACs (2-ton) come with the same start capacitor, but they may have a different Compressor Run Capacitor -- depending on the compressor type. (This may either be a 35uF matched to a Tecumseh compressor or a 45uF matched to a Panasonic or Matsushita compressor.)
* The original Compressor Start Capacitor that came in 65xx Series Basement AC was Part#1497-086, but at some point that number changed to Part# 8333A9021. ...What I cannot say is if they changed the capacitance or not?
* The original #1497-086 part also came with a P.T.C.R. So after reading your AirXcel Part# 8333A9021 installation instructions it would appear they are generic. I.e., they are written to cover the UPGRADE to a start capacitor in a roof top AC that may or may not have come with this type of part.
* As to why they dubbed this a "Hard Start Kit" I would have to say it implies they boosted-up the capacitance value, but that's just a guess. To verify this we would also need to measure the capacitance for a new Part#1497-086 start capacitor.
* I am curious to know if they called Part#1497-086 a "Start Capacitor" or a "Hard Start Capacitor?"
As we wind down this subject -- to better understand how our ACs startup -- and what we can do to extend compressor life:
* It would appear AirXcel already recommends using a Hard Start Kit (Part# 8333A9021) for all types of roof top and basement AC. And it's now obvious to me that our basement AC types already come with a Hard Start Kit.
* These start capacitors are there to increase the start-up torque, applied to the compressor, and then the Start-up Capacitor drops out of the circuit after the start windings in the compressor heats up... in milliseconds.
OTHER QUESTIONS
So how is it that one part can work in both roof top ACs (~13,000 BTU) and basement ACs (2-ton) type systems?
==> I would think that's because your roof top AC has just one compressor vs. our basement AC that has two. (I think this is right?) If this is not right, then we definitely need to know the capacitance value of that AirXcel Part# 8333A9021?
Once we find out what the capacitance value is to this AirXcel Part# 8333A9021, then we can compare that to other Hard Start Kits in the market. ...But you may ask, "Why is this important?"
Here's my assumption: This is just a guess, but I think if you are having some compressor START PROBLEMS, then you might be able to eak out a few more years of operation by going to a slightly larger Hard Start Kit. ...And maybe this is why we see people installing a SPP6 type part? ...Either that or they are installing these things because they read about other owners doing this with success, but I also now think it's a gamble. Why?
I'm going to say it's a gamble, because a stronger Hard Start Kits may also shorten the life of your compressor. (TBD) ...But at least we have a cheap option to keep our ACs running; and practically anyone can install these easily!
So what's all that talk about using a 5-2-1 Hard Start Kit?
==> I'm guessing this is there we (or me) have overlapped home AC repairs with RV AC repairs. And while it appears most heating and air conditioning professional prefer the 5-2-1 Hard Start Kit over using a SPP6 type Hard Start Kit -- these upgrades are probably too strong for our ~13,000 BTU compressors. ...Who can say until we find out the capacitance of the AirXcel Hard Start Part #8333A9021?
...On the other hand, a 5-2-1 looks like a better design (vs SPP6) and a 5-2-1 is not very expensive also.
...So I think its possible to use one of these 5-2-1 in place of a SPP6 type Hard Start Kit, but why would you care since our RV ACs do not run that much -- compared to a house AC unit that is. So go cheap.
Overhaul References:
* Be sure to read this link to Bill Elsenpeter's, "A Complete Coleman-Mach 6535 Overhaul" which is EXCELLANT. Thank you Bill!
Coleman Mach 6535-471 Wiring Diagrams - With Color Edits
Here are few schematics I edited so you can follow the 6535 wiring more easily by color codes.
I also included a picture of a IEEE Relay Numbering Guide so you can more easily track where all the wires go to the compressor relay #1 and #2 and why.
I trust these diagrams will help you in the event the time comes for you to service your basement AC.
Note: The 9 wires from the Thermostat connects to the circuit board -- and those On/Off calls are sent to the compressor relay that turns the compressor on/off. So a relay is just a switch.
However, in the main schematic you will see Relay #1 is wired slightly different than Relay #2. This forces the #1 compressor to come on first; and then after a time delay, the second compressor will come on -- unless the Intelletec EMS/PMS drops the power to the #2 compressor due to shore power constraints. I.e., 20A/30A/50A source.
Anyway, I plan to replace my relays this season after 10+ years of operation and I'm guessing there are a number of you who have never performed a PM to your Coleman Mach AC?
Note: Pricing is cheaper from electrical supply companies. So shop in advance of your repair and you can save a lot of money on parts.
Also, you need to verify all the part numbers for your AC model, but most part numbers seem to be interchangeable. Here's a link so you can find your Coleman RVP air conditioner model and parts:
Good luck to us all when the time comes to overhaul these things, but I think if you are armed with this information, all you need now is an $180 lift table you can get at Harbor Freight, because this 2-ton AC box weighs 200lbs.
==> Can anyone verify you do NOT need a lift table if you have a couple guys to help you lift it... or move it out so you can undo the lid with the AC resting on some supports? ...I have seen pictures of two 5-gallon bucket turned upside down with a board across the top, but I don't know how those owners slid the AC out of the frame-hangers?
I admit that, at first, I thought you were over-thinking a relatively simple project, but you've uncovered quite a bit of valuable information. I'm bookmarking this for future reference.
__________________
Bob C
2002 Itasca Suncruiser 35U
Workhorse Chassis
As promised , ill add more to the mix by posting all that is in my 6537-671 unit .
I am also on the fence about the term Hard Start .
Pictures they say are worth a thousand words .
There is no other information on the top part of the blower start Cap other than the # 1808 , in comparison to the original one .
But as you stated the number on that cap is 1427-086 . Values are the same on both caps.
Also included are full instructions for the start Cap . Which only shows installation only on roof top units .
Let me know if im missing anything .
I am taking my time to learn all this also . And will also replace both the compressor run Caps which are 45's , and both relays .
By doing so , I believe I will be covering all bases .
I'll also keep my fingers crossed for security !
Bob C: Yes... I was getting frustrated and confused, but then I traced the wiring diagram and it all started making sense. Then I got more committed to figuring this system out.
Plus AirXcel did not do me/us any favors showing a roof top AC diagram and giving generic instructions... where they target the roof top AC users.
AC MAINTENANCE
I would guess these Basement AC are the most neglected "system" in our RV, because you just have to take one look at the mess of wires and then decide to take it to the shop.
Consequently, not much definitive information has been written; and by just reading this tread you can see how confusing everything has been.
Now that the cat is out of the bag, I think it's really quite easy to do a PM service on your basement AC. This will help your AC run better and keep you from spending big bucks if your compressor fails just because you did not know how to easily replace your run capacitors. Or you did not think to inspect your start capacitor for melt down.
Anyway, with your help, Heating Man's comments, and Journey Cat's thread that got me thinking.
Here's some more info I was able to clarify:
The Model 6535 in 2004 only came in a 6535-671 series with a Panasonic Compressor.
...but 2005+ coaches came with two types of compressors and this second series is called a 6535-871. And that's why some people have 35uF to go with their Tecumseh compressor while us Panasonic / Matsushita compressor users take a 45uF Run Capacitor.
Like this:
6535-671 (1450-2229 Panasonic Compressor) takes a 45uF (370V or 440V) run capacitor
6535-871 (1450-2149 Tecumseh Compressor) takes a 30uF (370V or 440V) run capacitor
NEW TOPIC
Now that we know these Hard Start Capacitors spec at 88uF - 108uF one could think about using another type of P.T.C.R. Hard Start Device... with one exception:
What I have learned is that these P.T.C.R. devices are supposed to open at 75% of the maximum compressor power/speed. That said, even if you find another Hard Start Kit, like the SPP6 first mentioned in this thread -- that does mean the P.T.C.R (Thermistor) is those devices will open at the same ohms (heat point of the compressor start winding).
On the flipside, we do know is that people are using these other Hard Start Kit brands with or without knowing if they are hurting or helping to extend the live of the compressor. (Typically roof top owners.)
That said, until someone compares the AirXcel #8333A9021 to a SPP6 device... and provides us with some detailed electrical measurements for comparison, I have to highly recommend to only buy the AirXcel Hard Start Kit.
As for home AC repair: We know house professional AC people are using these SPP6 and/or 5-2-1 Hard Start Kits in those systems; however, their goal is to both extend the life of their larger house compressors -- and save money off their electric bill. ...And now that I have learned a thing or two about Hard Start Kits, I would suggest to most house AC users that they might want to invest in 5-2-1 Hard Start Kit or spend $200 or so and get a Soft Start Device!
...But us RVers really don't care about the cost of electricity, because our electric bill is already paid for in our park fees. So installing a Soft Start Device in an RV is cost prohibitive, and while I would say a 5-2-1 might be a better Hard Start Device for a home AC system, it is overkill for an RV. I.e., just keep using the AirXcel until we know of another substitute as described above. (Game Over.)
I'm hesitant to post more information, but I really think these pictures will help everyone understand how these Basement ACs work. I know I learned a lot creating them!
NOTE:
* I can't guarantee I figured everything out, so please double-check my work.
Help or caution on relays !
In mine its a Potter & Brumfield T92P7D22-12 . When I search that # I come up with several different styles .
Some have 8 terminals . I HAVE ONLY 6 Which most I see do also.
Made either in China as my original is or Mexico
There seems to be another name above P,B which is ETE .
Mine are labeled 25A 380V - The others are 20A 400V
Are there any opinions on the two differences ? Before I place an order ?
As it seems that also buying direct from Coleman they show 20A also . As we know details are vaugue on several A/C items
Journey Cat: Since you are replacing your old relays with new ones, might I ask you to open it up and look at the point wear... and then tell us how much use you think your AC has? (No doubt this will be a destructive test, but you can keep the other old relay as a back-up or for use on another project.)
I also think you posted pictures of your Start Capacitor (P.T.C.R) relay melted... so it will be interesting to see if your relays are in bad shape too?
This device can be removed from the Compressor Start Capacitor and replaced, but here's what I discovered:
* The PTCR (aka Motor Starter) is patented.
* Atwood sells this part. See picture blow. Atwood called just the Motor Starter
by Part #WSX7, which replaces WSX-5ACM.
* Dometic also offer this part, but most often you buy the P.T.C.R. (WSX7) with the Compressor Start Capacitor; and I see a number of RV Dealer who charge $45 each. (And replacing two is $90+... Ouch!)
* The cost of the PTCR (WX7) alone is in the $20 range... and that if you can find just the WX7 sale. (See picture below.)
IMO, if your capacitors are old (and they show wear) then you should probably replace both the PTCR (Motor Starter) and the Compressor Start Capacitor at the same time.
Together these parts are sold as a "Hard Start Kit" under the Part #8333A9021; and the average price is in the $30-$40 range. (2x = $$)
I suppose if you know your capacitors are relatively new, and just your PTCR burned up at a park that has really low voltage, then maybe you can get away with just buying the WX7 at $20 each, but chances are you can't find one fast enough and it's hot outside when you need to replace these.
Next subject...
How do you properly size a Hard Start Kit?
Good question? ...IDK.
Journey Cat just bought a Compressor Start Capacitor, with the PTCR (Motor Starter) on top, but his label shows a "1808" printed on the PTCR.
Why this is the case I do not know? I'm sure it is okay, but I have to say we really do NOT know what is inside these relays? ...And since someone owns the patent I'm guessing this "1808" is a knock off. (TBD)
I don't think it's a big deal, but as mention in previous posts: IMO, based on my research only and not field work, you really can't (or should not) just take a SSP6 Hard Start Kit off the shelf and use it in your air conditioner -- if you can't both verify the capacitance (which we can do easily enough) -- AND MORE IMPORTANTLY, know the thermistor type used to build the PTCR device is compatible. WHY?
...Because as mentioned earlier, that thermistor is trying to sense (by measuring the heat of the compressor start winding) when it is time to open the circuit. And the the goal is to open this circuit when the compressor reaches ~75% of it's top speed.
...So if you buy a SPP6, even one that measures 88-108uF, you still don't know when that PTCR (thermistor) is going to open the circuit!!!
...So using a SPP6 might be okay; and maybe even better than using the AirXcel Hard Start Kit; but it can also leave you worse off. We just don't know?
What would be nice to know from a Heating & Cooling Professional is this: How do you properly size a Hard Start Kit?
Journey Cat... This relay has the brand name manufacture and the same part number. (Potter & Brumfield T92P7D22-12)
I think the confusion is the 12V ad shows a picture of a 24V Relay.
I think you just need to specify the "-12" for 12V applications when you order. I.e., a 24V Relay would be a "-24". I think?
Let me know what you find out. I need to order 2 myself.
Note: The Product Code Key below says this is a "T92" type relay; and the Contact Arrangement is "7" ...which I find interesting. ...But since you know your old relay part number is correct, I guess "7" is also correct even though there is room for 8 contacts. My guess is your old relay is not populated with a 8 male connection pins. Is it?
Also, please let us know where you find the lowest prices when you get a chance. Thanks!
Journey Cat: Can you let us know if there is a "bleed-off" resister on top of your Compressor Start Capacitor (88-108uF)?
I'm not sure if there is one there or not? The Colman schematic says there should be one, but I'm wondering if that is true?
This picture is another capacitor with the resistor I'm asking about. This capacitor is not for RV use. It's just an example.
=== /// ===
And the other thing I am curious about is if you can measure your Compressor Ohms using the wires in the electrical box area? ...Or do you have to measure it at the compressor, which can only be done with the AC removed from the frame?
I found an obscure reference as to what you should expect the resistance of the Run and Start Winding should be:
* The C-to-R ohm reading should measure 0.63 ohms, (+/-5%).
* The C-to-S should equal 4.42 ohms , (+/-5%).
Note: It's possible these values are switched.
Note: Whatever resistance you measure at the electrical box, assuming your compressor is within factor spec, then you will have a reference point for any future AC-Compressor diagnosis in the future.
==> The compressor schematic in the above posts will help you identify the right wires in the electrical box to identify the right wire color that lead to the compressor.
Note: This may be a mute request if the compressor has some sort of protection device (Overload Device) that makes reading the ohms at the electrical box useless. So I hope I'm not wasting your time?
On the other hand, I think if you can get a good compressor ohm reading from the wires in the electrical box, then this information will be appreciate by all who want to know it is possible to check the condition of your compressor without removing the AC from the frame. ...And I think that will be pretty cool!
I called Newark . And the number provided was to India ! They say the parts are located in the USA But giving the unit number and the relay number .I was told they cant reference it .That combined with the language barrier .
Ill check the resistance once again . Although from previous reading of the run Cap was about 10 . And it does not have the resistor across the terminals .
i took a quick look at the link you provided and will admit i have not the patience to grasp all that info !
On another note the relay from China has 8 pin and 20 Amp where as mine is 6 pin and 25.A
This A/C project is greatly taxing my patience !
Well I rolled the dice on the relays No matter how I search for them . I come up with a varity of names weather i search for Potter & Brumfiels T92P7D22-12 or go by the RVP number 1460-1131 The only difference i see is that on the lower right side . Mine states 25A 380 V Every other search comes up with 20A , 400V
That being said I believe i cant go wrong with this deal
Journey Cat: I know what you mean. Just remember you started this! (ha ha)
As mentioned earlier, I found Journey Cat's thread first. There he was explaining everything what you need in order to service your basement AC after you remove it from the frame supports -- short of replacing the compressor. Thank you very much Journey Cat!
His work got me thinking about how these basement ACs work and what the components do.
That lead me to ask a lot of questions and make some false assumptions. So in an effort to get things right, let's not forget this is a forum where we will stumble from time to time, but with much dedication, I think we are getting close to a final conclusion.
I'm doing this so I can be armed with information in the event my AC needs an overhaul/Repair, because the thought of buying a new basement AC for $12,500 + installation is out of the question.
Moreover, I really would not want to ever own an RV with noisy roof top ACs again! And all the bad press about these basement ACs comes from the limited number of refrigeration mechanics who will work on one. ...But this does not mean they are flawed or poorly designed. I just means the more pain and unknowns a mechanic can insert into your mind set the more he can charge you.
Without a doubt, AC refrigeration is part science and part "art." Meaning the easy stuff you can measure, like capacitors, but the hard stuff comes when you have a leak, or you need to replace a compressor. So the goal it to avoid that! And the good news is that you can... if you know how to service your AC yourself.
Journey Cat: When you are done with your project and rested, we all would really appreciate a summary of your part costs and where you bought them. I know you have 95% of the information already assembled, but nowhere have I seen a complete summary in a spreadsheet.
No rush, mind you. I know you are "so-done" with this project, but if you think of all the money you are saving; and how much help you are providing to the rest of us... I know I appreciate your sojourn!
=== Back To Choosing The Right Compressor Relay ==
Journey Cat: Yes, I think you found good Tyco Electronics brand compressor relay on Ebay, at a great price, this is a direct replacement to your old Potter & Brumfield T92P7D22-12 relay.
I also think you are correct by staying with the part number you know to be accurate; and I would not worry about the difference in print on the side of the part that shows different current ratings at different voltages, because they all correlate.
...And thank you for your leg work. I will order a pair for my AC system.
Note: It's not uncommon to just "clip-off" relay pins that are not used, but when you can order a 6-pin T92 type relay for $25 (includes 2), then why bother ordering a 8 pin T92.
...Question for you: Does the female side of the relay socket have 8 or 6 pins?
More about testing your compressor while you have everything apart...
It would appear, for a reasonable sum of money, almost any RV owner can perform Preventative Maintenance (PM) on their basement AC -- that will hopefully prevent a premature failure of your compressor.
And speaking of compressors, here's a video on how you can check the health of your compressor:
...And yes this video shows the author testing a residential AC compressor, but the process is the same for RV basement AC compressors too!
For example, in my #6535 with a Panasonic type compressor, these are the ohm ratings for each winding as best I can tell. (I'm not absolutely sure, but I think these are correct; and your compressor if different than mine may have different resistance values.)
These values are at the compressor, but I see no reason why you can't take the ohm readings between the correct wires in your circuit box... when you have a good working system... and then you can keep these number as a reference for another date... and use them for comparisons and troubleshooting purposes in the event you think you might think you have a compressor problem. (This is a tip I can not confirm, but it sounds logical to me. So I hope it helps you in the future.)
Journey Cat: Can you take a picture of your Compressor Label so we know what type your system came with?
Does anyone know where we can buy R22, 115V Panasonic Compressors to replace Part #1450-2229?
What about Tecumseh Compressors with Part #1450-2149. Where can we find a replacement for these?
Comment: I found a reference from AZ Expert in one of his video where he used an "EasySeal" product to fix leaks in a Basement AC system, but I don't know much more about this product than what this video shows:
There is no female side plug to the relay .
They are individual wires , at least on my model .
Also here is the compressor .
And there is plenty of R22 for sale on EBay
Its now just a matter of time waiting for the parts , to hopefully see it operational once again . Fan blades & bearings included
Journey Cat: You are right. All these compressor relays have wires connected. I got confused with what people do with Bosch 5 pin relays when they only have a 4-pin female socket.
So now that we have the compressor relay subject covered, and you told us where to buy a set of two relays on Ebay for cheap, I found a new subject on another part that you should look into... since you have full exposure to the top of your compressor.
The Compressor Overload Circuit Protection (Part#1450-0081)
* Check your parts list. On mine #17 is the Overload Circuit that protects the compressor from overheating. Or at least it is supposed to.
* I'm guessing this thing works like a house dryer thermal cutoff switch. This means the spring loaded contact presses up against the head of the compressor and makes contact with the metal.
* The Overload must therefore be a normally closed switch that opens when the compressor gets to hot; and it's there as a safety device.
==> I don't think you need to change this part, but like a dryer thermal switch, they are known to go bad.
==> I can't find any information on the internet about these things (Part #1450-0081) and it's not listed on the AirXcel website. So I don't know that the Cutout Temperature is? ...I.e., the temperature the switch opens and protects the compressor from overload (high temperatures).
==> I might suggest you call AirXcel to find out if you can order one or not. And if not, or if you don't want to replace it, then you might inspect it to make sure the contact is clean.
Here's a video on how I discovered this part, and sure enough our basement AC come with an Overload Device. (Part 17 in my parts list, Part #1450-0081)
Compressor Overload Protector Testing! How it Works!
Note: On top of my 6535-671 with a Panasonic Compressor, my OVERLOAD Circuit Part Number is #1450-0081. This Overload Protector attaches to the compressor and shuts off the compressor if the compressor motor draws too much current. I think this is a normally closed P.T.C.R. switch.
And below are some pictures of a rotary compressor head taken from the video with an Overload Circuit type that looks a lot like the on on top of our Panasonic compressors. ...But again, if these parts don't fail that often, you might just clean you old switches and "call it good" as the AZ Expert likes to say in his videos. On the other hand if you can find a second source for cheap, then please let us know what the cross reference part number is after you talk with AirXcel.
Linear Mode
