How DO YOU ADD A 5-2-1 Hard Start Kit To Your COLEMAN-Mach (2-Ton) Basement AC?

[imnprsd]

In my earlier post I learned what a "Hard Start Kit" is and how it is used. To summarize briefly, all Basement AC come with a Hard Start Kit (HSK) and most roof top AC also come with one. However, the roof top AC has a smaller compressor and therefore a roof top AC uses a smaller Start Capacitor vs. the 2-Ton Basement AC used in may RVs from 1996~2010. (After 2010 only Roof Top AC were used.)

So what is a Hard Start Kit and why do you need one?

Here's my answer:

* In RV terms a HSK consists of a start capacitor and WSX7 Motor Starter, which is a PTCR-thermal type switch. In residential terms a HSK consists of a start capacitor and a 5-2-1 relay.

* A hard start kit is used to help to start your compressor for split seconds, then it the PTCR drops the start capacitor of the circuit. (I will not explain why, but this is the desired effect.)

* You also should know, that prior to the compressor reaching 75% full speed, the compressor coils behave like a heater. And the start winding not only has more ohms vs. the run winding, it also has thinner gauge wire. Therefore, your start winding is typically more susceptible to heat-fatigue and failure over time. And if at any time the PTCR fails you could damage your compressor.

* Luckily, the PTCR does not fail that often, but it is susceptible to melting-down when you use your AC in RV parks with low voltage. However, it is a very reliable, and cheep device. ...But is it the best device for the job?

WHAT IS THE DESIRED AFFECT?

* First let me say, the run capacitor is specified by the compressor manufacture and you should only use the right micro-farad run capacitor matched to the compressor. In the case of a my 6535-671 Basement AC this is a 45uF run capacitor, but some other models that came with Tecumseh compressor they call for a 35uF capacitor. (Just be sure the use the one matched to your compressor.)

* The compressor manufacture does NOT specify the type or size of a HSK. But if you look at your OEM start capacitor you will know. ...But what about the relay?

* What about the relay? How do they create a time-delay so the start capacitor remains "in the circuit" for a estimated period of time... and then the relay trips to take the start capacitor "out of the circuit?"

* Answer: All RV manufactures install a a small, cheaper start capacitor; and all RV manufacture use a cheaper WSX7 Motor Starter (PTCR) to put the start capacitor "in" the circuit... until it heats up, and the the PTCR takes the start capacitor "out" of the circuit at an estimated 75% of full power.

* But all this is just PTCR is doing is acting like a time-delayed switch, which is a crude estimate at best. (...but proven reliable, nevertheless.)

REVIEW

The RV industry is smart. They build reliable products for a cheap as possible. Ergo, our Basement ACs and most roof top AC will last 10+ years without any maintenance or they could fail in 5 years.

Owners, don't think of doing Preventative Maintenance (PM) on their ACs, but they should. And it's so easy and cheap do to! So why haven't you heard about this subject until now? ...Good question? ...And now that you have, when are you going to PM your AC?

The problem is that these electrolytic capacitors typically leak and are not within spec after 5 years. (My estimate.) So the first thing you should do if you have never checked your run and start capacitors is to properly check them and replace if necessary. This will do wonders to extend the life of your compressor and avoid huge repair cost. Plus these capacitors only cost ~$10 each so the parts cost is cheap! What you lack is the knowledge on how to replace your AC run and start capacitors! ...But it's easy! Anyone with half a brain can do it.

* SAFETY PRECAUTION: Be sure to short the top of your capacitor (between pins) before pulling any wires and watch a YouTube video on how to do this. (Piece of cake.)

SO WHAT IS A 5-2-1 HARD START KIT AND WHY SHOULD I UPGRADE?

* As stated above, your coach manufacture builds a quality product, but unfortunately for owners they sometimes care more about profit margins over building the best product they can. And I'm thinking if that was their goal, they would have used a 5-2-1 relay instead of a WSX7 Motor Starter (PTCR).

* A 5-2-1 is a relay. The 5-2-1 represents the pin numbers on the relay so you know how to hook it up. The 5-2-1 replaces the WSX7 Motor Starter (PTCR-Switch) in an RV application; and in residential AC it is standard equipment.

In fact, when residential ACs undergo a repair, the tech, often uses 2-wire Supco SPP6 (with PTCR) to diagnose the system; and then they typically only leave this cheap device installed for only as long as it takes to get OEM parts replaced. I.e., the 5-2-1 is always preferred to the PTCR device.

* Here's the challenge: In order to use a 5-2-1 relay you are supposed to know the right "Pickup Voltage" for the Back-EMF of the compressor.

* The problem RV Basement AC owners have is that the Panasonic compressor manufacture (and AirXcel-Coleman) does not provide technical support. So we don't know what the "Pickup Voltage" is.

* Replacing the start capacitor is no problem. We do know what type of start capacitor to use since it's marked on the outside case. And in most cases, the OEM start capacitor for a 2-ton Basement AC is 88-108uF.

* However, my research suggests that you can use a 135-162uF Start Capacitor in place of your OEM 88-108uF start capacitor and when you do you should not only get a faster and smoother start-up... as evidenced by listening to your compressor start... this upgrade should extend the life of your compressor, because those start coils in your compressor will not get a hot... if the PTCR or the 5-2-1 is "tuned" to take the start capacitor "out" of the circuit when the compressor reaches 75% of full power. (TBD)

At this point you can refer to this thread for more details on how I arrived at this conclusion; and I would recommend you jump to the last few thread entries to skip over my learning curve in the beginning:

https://www.winnieowners.com/forums/...de-359467.html

HOW TO "TUNE" YOUR 5-2-1 HARD START RELAY?

So now we need to talk about how to optimize the relay that takes the start capacitor "out of the circuit" after an unknown period of time.

This is currently being accomplished by a 22-ohm, WSX7, PTCR type, Motor Starter, but I wonder if using an adjustable 5-2-1 relay is a more efficient solution for the same amount of money or for just a few dollars more?

* 5-2-1 relays are supposed to me matched the the "Pick-up Voltage" specified by the compressor manufacture. However, as mentioned earlier, Panasonic/Matsushita will not answer my emails requesting this information. So what can we do?

ANSWER: Supco makes an adjustable ARP5 Relay that can be "adjusted" to match your compressor "Pick-up Voltage." ...And Supco recommends an adjustment between 180-190 on the trim-pot to achieve this. However, this is just another estimate.

HVAC TECHNICAL QUESTION: When you adjust the "Pick-up Voltage" on the APR5 (5-2-1 relay) between 180-190... can you discern the best setting by listening to the compressor start?

===> SO IS THERE ANYONE OUT THERE WHO HAS USED A SUPCO APR5 RELAY AND "TUNED" IT FOR OPTIMUM PERFORMANCE?

If so, please let us know how your experiences... pro or con... using one of these devices, because in theory, a "tuned" relay will drop out at ~75% maximum compressor power/rotation... and I would like to know from the HVAC professionals if they recommend using a APR5 over a Motor Starter (PTCR)?

Additionally, you owners in the desert states, who are finding your AC has trouble starting in 105+F weather, you would benefit from installing a 5-2-1 since it works on the principles of a coil switch and is not affected by outside temperature like a PTCR, WSX7 Motor Start is affected in hot weather.

Attached is a circuit diagram I created that shows how you wire a 5-2-1 relay to your Basement AC.

[imnprsd]

...One more thing:

CAN WE VERIFY THE BEST SETTING BY NOT ONLY HEARING THE DIFFERENCE (WHEN OUR COMPRESSOR STARTS)... CAN WE MEASURE THE DIFFERENCE BY CHOOSING THE BEST PICK-UP VOLTAGE SETTING BY MEASUREING "IN RUSH" CURRENT?

...Does a lower "in rush" current always signal a better setting?
...which in turn implies the correct Pick-up Voltage somewhere between 180-1909 on the Supco APR5 dial?

Last words: I don't care if I am overthinking this! It's fun and it's part experiment. I need the help of professionals who understand this stuff better than I do. So I thank you for sharing your experience if you have been using an APR5 and "tuning" it in the field for years on residential ACs. If you don't have this experience, then I humbly ask for your thoughts based on EXPERT knowledge.

Those of us who are willing to give it a shot, we need your feedback too!

[lenore]

Just a side note, most home air conditioners do not have the hard start 5-2-1. The manufacturers took them out decades ago to save money on their end and also give a known failure of the start caps. Keeps the industry in money, but cost the consumer. my personal compressor was drawing 80amps on start up and struggling. After I added the compressor saver the amperage on start up dropped to 21 amps. Saved me from buying new air conditioner for awhile.

[imnprsd]

lenore: I'm glad you posted your comments, because your feedback helps to explain why I started this thread.

...But I'm not sure you are correct about most residential ACs no longer use a 5-2-1. IDK... so I will let other forum members with HVAC experience comment on that. You may be right? ...On the other hand I can't see a residential AC manufacture installing a $329 device to replace a $20 Hard Start Kit. And I certainly know RV manufactures do not.

My goal is to optimize my RV basement AC performance for the least amount of money.

You said you use a "compressor saver". By that do you mean you replaced your 5-2-1 Hard Start Kit (which consists of a start capacitor and a 5-2-1 relay, or your AC uses a start capacitor with a PTCR Motor Starter) and you replaced it with a "Soft Start Kit" or "Energy Saver" like this on on Amazon for $329?

https://www.amazon.com/SoftStartRV-N...0734634&sr=8-5

And just to be clear, you did this to your RV-AC, right? ...If so, do you have one or two ACs on your roof?

I have two compressors, so buying 2 of these things will cost $600-$650 and that's a lot of money to spend if it does little for me. I can say this because I have a 7500W generator and I have no trouble starting up my AC, but I am aware smaller RV owners with smaller compressors need to install these things to keep their generator from stalling out and to keep their circuit breakers from popping on hot days.

In any event, it sounds like you verified one of my concerns. That the "optimal" start-up conditions can be confirmed by measuring your "In Rush" current.

It's my understanding these solid-state "Energy Saver" or "Soft Start Devices" ask you to start your compressor several times so it can optimize settings, using proprietary algorithms, to achieve the lowest "in rush" start-up current. And everyone who uses these seems says they are great!

I just do NOT want to spent $600+ to install 2 of these things in my basement AC that is running very well with a run capacitor and a Hard Start Kit.

I also want to know, which is the point of this thread, can I/we adjust this Supco Adjustable 5-2-1 relay... called a APR5 for $20... to achieve similar start-up optimization results as these "Energy Savers" that cost $329 each? ...And if we cannot get close to the Energy Saver performance, can we adjust the APR5 to deliver better AC start-up performance vs. the Hard Start Kit that Colman-Mach uses?

...Essentially I am asking:

* Will installing a 5-2-1 in place of the Motor Start work better in our basement AC or roof top AC?

* And will using an adjustable 5-2-1 extend the live of our AC compressor?

If so, we are talking a $40 cost of building what I call a "Poor Man's Hard Start Kit" vs. $658 for two "Soft Start Devices" aka "Easy Start".

Here's a related question: I know these these Energy Saver devices replace both the start-up capacitor and relay (either a 5-2-1 relay or a PTCR Motor Starter), but I don't know if these Energy Saver Devices also replace the run capacitor? Do they? I.e., do these things also optimize the run capacitance in addition to optimizing compressor start-up?

[lenore]

No the kit which is a basic3-2-1 kit is installed parallel to the Start and run circuit. It does not replace the start cap. Works great by the way as the compressor was immediatly quieter. A bad Start cap can also cause this issue. I measured mine and it measured exactly the specs on the capacitor. The kit I installed cost a whopping $35 from Amazon. My local air conditioning company was going to charge me $800 for adding this kit, his mistake was informing me that he was going to add a compressor saver kit (5-2-1 ) Through talking to my old neighbor (HVAC guy) he said all air conditioners years ago had this device, they took it out to cut manufacturing cost. Than when only the start cap dies (because they are crap now that the real oil in them is no longer a environmental danger) your compressor struggles to start.

[deucehotrods]

Thanks for this great thread on the basement air subject. My 2005 Winnebago Adventurer 38R is still working great, but I'd love to learn more how to preserve and protect it in the future.

[imnprsd]

lenore: So you are not a HVAC expert? NP I'm not either. ...And your neighbor suggested you install a 3-N-1.

...And you have a 2020 RV with a roof top AC, is that correct? ...Not a 2-Ton Basement AC, which is the focus of this thread. ...but okay. You bring up another good point.

Here's what I know about 3-N-1 or 3-In-1 Hard Start Devices:

https://www.supplyhouse.com/Supco-RC...a014032f7e2042

Device Application Notes:

* 110 to 125VAC Solid-state Hard Start Relay, includes relay, overload, and start capacitor. Used refrigeration systems without run capacitors.

*Rated for 1/4 HP to 1/3 HP compressors. Maximum RLA 6 Amps.

* Replaces relay, overload and provides a boost for hard start and unbalanced systems

* Prevents low voltage starting problems

Here's 2 on amazon for $19:

https://www.amazon.com/RCO410-Hard-S...71&s=hi&sr=1-7

So last month when I talked to Supco they did not recommend using this solid state device in RV. I pressed them as to why and I did not get a good answer. He just said to stick with the SPP6 and that they have been getting a lot of good feedback from RV owners. This engineer also said they do not support the RV market.

Okay... Still, I have every reason to believe a 3-N-1 device will work, but the real question is for how long? ...And does the capacitor value degrade quickly or even fail over time? ...And just how well does a 3-N-1 interact with your compressor? ...Does it harm the compressor?

FACT: Techs typically use a 3-N-1 devices to diagnose an HVAC problem. This typically involves a warn compressor that does not starts or trips breakers when trying to start. And they carry one of these, just like they carry a APR5 (5-2-1) because a tech cannot carry all the right-sized components needed to service every job. So these Hard Start Kits are again a crude-fix. And I want to know how to "fine-tune" my basement AC start circuit. I don't want a crude fix even if it starts a compressor that would not start or pops circuit breakers or kills my generator because it's too small (I.e., can not handle the "in-rush" current during start-up.)

lenore: Are you saying you used a 3-N-1 without removing your run capacitor? ...And are you saying you did the work? ...And you modified your newer, 2020 RV-AC? ...If so, why do you think your AC was having problems within 1-year?

Again, I'm not sure where you are coming from, but it does sound like you are very happy with your "in rush" numbers dropping after installing that 3-N-1. But it also sounds like your RV-Roof Top-AC was having problems to begin with. Is that right? ...Or does your neighbor know Dometic (if that is the roof top ac you have) does a very poor job starting your compressor; and that using a 3-N-1 is a good and reliable upgrade that will not harm your compressor? IDK. I'm just asking so other roof top AC owners know what the tradeoffs are.

Note: Newer RV-Roof Top-AC are wired different than RVs that came with a Basement AC, but the principles are the same. Basically, you want to start-up the compressor with the help of a start capacitor (which adds starting torque for a momentary period of time) and then you want to keep the compressor running at optimal power after it starts.

However, when you over boost your compressor, or you have to keep it running with a Hard Start Kit like this 3-N-1, then I would like to know if you neighbor warned you that using one of these may only work for 1 month or 1 year or 3 years? ...You never can tell.

...I.e., you know this is a last ditch effort before you have to replace the compressor, right?

So as I said, raising this 3-N-1 subject is good. It tells people they may have a very inexpensive option to getting through their summer vacation with a WORKING AC. ...But you should know this fix or upgrade may mean you are probably running on "borrowed time!" (...Aren't we all? ...ha ha)

* And just because the Supco engineer poo-pooed the idea of using a 3-N-1 that doesn't mean I wouldn't try it if I was faced with a $2,000+ AC replacement. What have you go to lose?

So... back to the subject of this thread: Who can tell us if there are real benefits to using an Adjustable (APR5) 5-2-1 Relay, and can you "fine-tune" the relay, to reach the right "pick-up voltage" to match the compressors Back-EMF; and will using a slightly larger start capacitor also be beneficial?

I tend to think it's possible, but I will not have access to my RV until April/May 2021 to do some field testing. So who is willing to give it a go? And/or is there a PROFESSIONAL HVAC PERSON out there who knows what I am talking about and can either confrim or reject this proposal I dub a "Poor Man's Hard Start Kit."

...Or is the only real option to improving AC efficiency going to cost $329/compressor, or twice that cost for us Coleman-Mach (2-Ton) Basement AC owners, if we elect to install a "Soft Start Kit" (one for each compressor)? ...So with labor that's a $1,000 bill. So this subject maybe an $40 alternative. IDK. I'm trying to find out!

[Heating man]

I have been a heating and A/C tech for 40 years. Residential A/C units don't need hard start kits unless there are problems. with starting. Generally hard start kits are only needed with hard shut off expansion valve metering refrigerant devices. Most units now use scroll compressors and these equalize pressure quickly and if thermo expansion valves are used they bleed through so unit does not have to start under the load of differential pressure of high and low side. In residential A/C units no start components are needed if pressures are equalized. They do need run a capacitor to start but that is all. The compressors used in RV A/C units are mostly rotary compressors which are fast equalizing also. The only reason I can think of that an RV A/C needs start components is for low voltage starting.

[imnprsd]

Heating Man: Good to know your thoughts. Our RVs do have to overcome line pressures when starting, but I understand this is milliseconds in duration.

I also understand low voltage starts causes the WSX7-PTCR to melt after repeated starts. So this may suggest a 5-2-1 relay would be better suited to do the same job.

In addition, a PTCR device sometimes cause re-start problems when the OAT is above 105F. So this is another benefit to using a 5-2-1 relay.

...But no one uses these. Why? I'm guessing 1% do, but they have not answered the call on this forum.

That said, I would conclude there is no value to changing from a PTCR to a 5-2-1 relay unless you know you are operating your RV AC in hot-hot weather and/or you are always in a park that is known for low-voltage. ...But even then you would want to use a Hughes AutoFormer to help with that above all else, and that would address your low voltage problem.

Heating Man: Have you ever installed a APR5 adjustable 5-2-1 relay and can you "tune" it to match the Back EMF of the compressor?

...And by tuning, I mean have you ever compared the "in-rush" current at different settings?

...And can you hear a difference when the compressor starts from one setting to another?

I bring this up to learn if there is a "poor man's" approach to using a APR5 vs. spending $350/compressor for a Soft Start Device? ...And I ask this as an RV owner with a 2-ton Basement AC, not as an RV owner with Dometic AC on top of my roof; or as a Class C owner with a small generator that his having trouble starting my roof AC.

I merely want to know:

1) If I install a 5-2-1 relay, how do I set Back EMF when I can't get this setting from the Panasonic compressor manufacture?

2) Will it extend or shorten the life of my compressor?

3) And on a separate subject, do these Soft Start Devices optimize/change the run capacitance? ...I.e., if I install a Soft Start Device will the AC not only start faster and smoother... with less "in-rush" current; will it also run a lower amperage after the compressor starts -- using a Soft Start Device like this one on Amazon:

https://www.amazon.com/EasyStart-Mic...%2C289&sr=8-21

[peggwn]

imnprst - We do have basement air and I too am interested in using a 5-2-1 on each compressor because I cannot afford 2 Easy Starts.

Just for an FYI aside, we have a fairly new AC unit at our S&B and recently had a check-up. All was fine. I asked if a 5-2-1 would make life easier for the compressor. He said definitely YES, and he wanted $340 to install one. I declined because I know they only cost about $28 and I could follow instructions. He did say that had they installed our unit (about 3 yrs ago) they would have suggested a 5-2-1 because they feel like they do prolong the life of the compressor. He added, as others here have said, they do recommend installing one when an aging compressor is struggling, so one could get some more time before needing to replacing it.

I did buy and install a 5-2-1 on the S&B AC. It does seem the start more easily and quietly. I don't know about and adjustability for the 5-2-1,

In response to your 3rd question, I believe the answer is YES to each statement.

I have been checking my capacitors regularly because I have had to replace them once, both the start and run capacitors for both of the units. It was very easy to do.

I would consider installing 5-2-1s if the result of this thread is that they would help in very hot Texas weather.

Keep after the answers.

[imnprsd]

So I ordered the following parts to do some field tests on my Coleman Basement AC, when I pickup my RV in April/May... which means I will be working on it until I get to my camp spot until May/June. So these comments are just to keep this thread going.

==> My hope is that someone else will try one of these suggestions and then report their results sooner than I am able to.

I plan to measure "in-rush" current as using the following combinations:

1) OEM Hard Start Kit setup: 88-108uF start cap + WSX7-22-ohm-PTCR Motor Starter.

2) Change the cap to 135-162uF, but keep the WSX7-22-ohms PTCR Motor Starter.

3) Change the 22-ohm PTCR to 33-ohms, keep the 135-162uF.

4) Change back to the OEM start cap 88-108uF, but use the 33-ohm PTCR.

5) Remove the Start cap and PTCR, and replace it with an adjustable (APR5) 5-2-1 Relay and attempt, move the settings between 180 and 190 while I take "in-rush" measurements. (Note: With a 5-2-1 you need to install a "bleed-off resistor" on top of the start capacitor so the points inside the 5-2-1 rely last a long-long time.)

And here's a news flash: Another forum member told me he used the 120V, SPP4E Hard Start Kit (By Supco) to replace his OEM Hard Start Kit (88-108uF start capacitor and WSX7) and he says this Supco SPP4E has been working very well for him in hot weather and warm weather.

So what is a SPP4E?

The "E" stands for electronic circuit that replaces the PTC-R (relay-switch) used in the SPP6. And both the SPP4E and SPP6 is rated at 88-108uF so this matches the same start capacitance used in the OEM Hard Start Kit.

Why use the SPP4E over the SPP6 or any of the above combinations?

==> The SPP4E is not affected by temperature because it uses electronic circuitry in place of the PRCR device to "open" the circuit.

So if you find your basement AC having trouble starting in 105F+ weather, then you might go with the SPP4E. However, the OEM Hard Start setup is proven, so I would stay with that unless you are operating your AC in 105F+ weather.

Consequently, the idea of going to an adjustable APR5 5-2-1 Relay may or not be the best alternative to fixing an AC that is having problems starting in very hot climates, but it still may allow for some start circuitry optimization. (TBD)

My guess is that if your AC is popping circuit breakers in 80-100F weather, then I would try bumping up the capacitor to 135-162uF.


And the reason I am swapping out the 22-ohm PTCR to a 33-ohm PTCR Motor Starter is all about the experimenting with the amount of time the start capacitor remains "in the start circuit".

I.e., the goal to optimizing the start circuit components to find the lowest "in-rush" values that we assume implies we have reached optimal start torque (phase shift) and we have found the the point when the compressor reaches 75-80% of full speed, which we cannot measure.

Remember, you want the relay to open (PTCR or "E" or 5-2-1 Setup) to "open" the start circuit... so the compressor continues running with just the RUN CAPACITOR "in the circuit."

My hope is that I can both measure and optimize the capacitor values and PTCR ohm rating to achieve optimal results.

I have no idea what combination will work best at this point. And I know I am totally overthinking this, but it's all in a days work when you are fully retired. So stand by and maybe by May or June, when I pickup my RV from storage, and then I will have some results to report.

[imnprsd]

Now that I have tuned-up my Basement AC I can post these conclusions and I will answer my own questions posted in previous threads:

Starting with "in-rush" current, this is in-rush of current that will last for ~1 second when the rotary compressor starts up. However, when I measured my "in-rush" on each compressor it turns out to be a range of 44-55A. And I think this has to do with a number of variables.

As mentioned the compressor is a rotary compressor so that alone is one variable. Another is OAT. And another is how long you wait between compressor test starts. (Note: The basement AC Circuit board has a timer circuit to prevent you from starting-and-stopping your compressor in too short of a time. So if your AC does not restart right away after you make a thermostat "call" then this is normal. Just wait 5-10 minutes and try again.)

To say the least, the whole "Hard Start" circuit is not an exact science. And even though the Motor Starter (PTCR) can be purchased in several ohm sizes, I found I was not able to lower the "in-rush" current by using an 18-ohm PTCR any more efficiently vs. using a 25-ohm PTCR. So if your Motor Starts ohms-out in this range of 18-25 ohms then it is probably working like it should. I.e., you will have continuity at rest, and then the PTCR is supposed to open when it gets to ~1000 ohms.

Note: : PTC stands for "Positive Temperature Coefficient" and the "R" means resistor. And the PTCR is just a bi-metal semiconductor thermal resistor with a positive temperature coefficient, which means that the resistance increases with increasing temperature.

When my basement AC compressor #2 had a starting problem, I found the PTCR mounted on top of the start capacitor was registering 1100-ohms and it failed the continuity test. ...However, the start capacitor was measuring 100uF which is within spec. So all I needed was a WSX-5 Motor Starter with the PTCR inside.

Much to my surprise, I was not able to order just the WSX5 for sale anywhere. ...And I looked everywhere.; ...The only way to obtain one of these motor starters is the order the Dometic Hard Start Kit (HSK), which includes both the start capacitor and the motor starter and it sells for ~$45 each; and you may need 2; or keep one for back-up.

Fortunately, these PTCR things don't go bad that often.

Then I got an idea. What if I ordered a new 22-ohm PTCR on Amazon; and then remove this good PTCR; and then put it inside the old WSX5 shell with the connectors I want... and it worked!

I removed the old PTCR from the WSX5 Motor Starter; and I inserted the new 22-ohm PTCR. It cost me $7 for 2 PTCR devices so now I have an extra one for future use. My point is that you should not throw your WSX5 away, because the WSX5 has a unique way of connecting to your capacitor by plugging in directly to it.

Note: A PTCR device can be bought on Amazon or at some Appliance Parts Stores.

A PTCR is just a bi-metal thermal switch (relay) that is "normally closed" at rest and then "opens" at ~1000-ohms.


And the time the PTCR remains closed is based on the time it takes the PTCR to go from 22-ohm to ~1000-ohms, and this is split seconds. The the PTCR "opens" and allows only milli-amps to pass through while the compressor is running. And this is what you want.

So then, the PTCR is a temperature sensitive device, and this is why some people have trouble restarting their air conditioner in hot weather... because it takes more time for the PTCR to cool off, without any current flowing through it. And when current is flowing through the WSX5-PTCR it will be hot to the touch. ...Maybe in the 170F-220F range. ...But it can get hotter if you are plugged into 110Vac vs. 120Vac since it will take more Amps of current to power your air conditioner. And this is why some PTCRs will melt... although that would really take a very low voltage of below 108V for that to happen and it will take some time.

In any event, if you do a visual inspection on all your capacitors and your Motor Starters you may find your problem component that way. And it's so easy to do. Just take off 1 screw that holds the cover over your air conditioner circuit box and everything will be very visible.

The problem is that a lot of RVers do not monitor their shore power voltage when they really should!

OTHER QUESTIONS AND ANSWERS

1) My OEM Hard Start Kit setup includes a 88-108uF start cap + WSX5-22-ohm-PTCR Motor Starter. ...And I recommend you continue to use this HSK, because it gets the job done and installing a 5-2-1 is more work than it is worth, since it's not "tuned" to your system. However, I would consider using a Supco SPP4E (electronic relay) in place of the OEM-HSK if you operate your basement ac or rooftop ac in weather above 100F a lot.

2) Should I increase my start capacitor to 135-162uF? ...I think not. ...I tested a slightly larger capacitor, but it had no positive or negative affects on my basement AC. However, my compressors are still running strong and start normal. That said, if your AC has trouble starting then I would bump-up the start capacitor size, but keep the same Motor Starter. Note: Theoretically, a 15-ohm PTCR will keep the start capacitor "in the circuit" longer than a 25-ohm PTCR, but it's negligible.

3) If you compressor is still having a hard time starting or re-starting after 10 minutes, then I would change the 2 relays for $25 (Part # T92P7D22-12) and try again.

4) When you have problems finding parts on the road, and you want your AC to work, you an go to any Appliance Part Store and buy the Supco SPP6, but you might try ordering the Supco SPP4E and pick it up at an Amazon Locker in a big city if you are near one. Note: Both of these are 2-wire devices and anyone can take out the old HSK and install these Supco HSK. And btw, you do not uses your WSX5 since the Supco HSK include the motor start under their cap.

5) The best way to start your air conditioner and to know it is running in OPTIMUM form is to buy a $350 Soft Start Kit.

Note: Us diesel owners with a 7500-10,000W generator should have no problems starting our RV air conditioners, but if you have a smaller generator and you are having trouble starting your air conditioners then your only solution is to buy the Soft Start Kit and you have pay $350 per AC or per compressor if you want one on your basement AC which has 2 compressors inside.

I hope these threads help you "tune-up" your AC for less money. And frankly if you check your AC every 3 years then you probably will not run into any trouble for many years to come.

Finally, if your AC is making more noise than it used to... take action and do a visual inspection and then use a multi-meter to check your capacitors and ohms on your motor starter. ...And above all don't wait to long!