Dometic Penguin AC Compressor Question

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Dometic Penguin AC Compressor Question

June 15, 2019, 01:05:08 am

Front AC compressor is not working. I replaced the two capacitors and PTCR relay last summer and that solved a similar no-start issue. Bought another set and put them in tonight and nothing changed. The compressor tries to start every 30-45 seconds or so, but wont run. It is hot to the touch. I checked continuity between the three lugs on the compressor and there is no short between any of them. I then checked the resistance between the three lugs and I got: ~0.8 run to common, ~2.1 start to common, and ~2.5 run to start. I checked the resistance between the three lugs on the rear unit, which works as it should, and I got ~0.8 run to common, ~4.4 start to common, and ~4.9 run to start.

I've read that A+B should approximately equal C. The good unit is closer to this equation than the bad unit, but not sure if there is a smoking gun with the resistances. The low resistance for the non-op unit compared to the operational unit makes me think there is something internally wrong that is not allowing this thing to start. I know I need to clamp the power wire when the unit is energized to compare the amps vs. the motor tag amps, but I don't own a clamp meter (yet).

Can anyone share any wisdom? Time to throw this thing in the dumpster and upgrade? This is a time sensitive issue as I have a 1 week vacation planned to St. Anthony's sand dunes for the 4th of July. Driving through Vegas at 120F requires all the cooling capacity I can get to keep from frying!!!

Re: Dometic Penguin AC Compressor Question

Reply #1 – June 15, 2019, 03:36:14 am

I gathered some additional data:

Non-up unit - measures 99v across run to common and 2.5v from start to common when it is trying to start up. I measure 105v from the start wire to ground on chassis when the unit is asked to start.

I measured voltage at breaker for non-op unit as well as voltage at the controller and both measured 116.8v.

Operational unit - measure 115v across run to common while running and 235v from start to common when running. I measure 260v from the start wire to ground on the chassis when the unit is running.

I have no idea what this data means, hopefully someone here has some knowledge of how these systems work and can point in the right direction. I find it odd that the operational unit has 260V on the start wire when there is only 120v power going to it.

Re: Dometic Penguin AC Compressor Question

Reply #2 – June 15, 2019, 09:33:46 am

With those ohm readings on the running unit being about twice the resistance as the non op one, sounds like you have a short in the motor winding to me.
If it were just a locked rotor condition ( not good either) the readings should be similar. I am assuming the units are the same make and size, if not then disregard my comment as the readings could be quite different.

If it were me and I was headed to the desert southwest in the middle of the summer,??, I wouldn't trust it. Especially if we are talking about and older unit anyway.

The 260v reading is not unusual for a running motor (120v single phase) as it is basically a rotating auto transformer.

Re: Dometic Penguin AC Compressor Question

Reply #3 – June 15, 2019, 09:45:28 am

"evantwheeler",

You speak of the compressor "trying to start every 30-45 seconds or so", when I think that you are more likely referring to the AC unit fan motor. The compressor is hermetically sealed and does not try to start for two minutes, or more, AFTER the fan motor has started (if thermostat settings and refrigerant pressures are calling for compressor start).
I think that you are more likely experiencing a "tired" fan motor. The way to know for sure is to know the normal and then current inrush current amps when you call for the unit to start. You can measure that with an AC clamp on ammeter, from the AC breaker at the foot of the bed. A stuck rotor fan motor will show five to seven times higher starting current than running current, before the control board times out and trips off the start time cycle. Another easy way to verify is to gently prod either fan squirrel cage wheel with a dowel or stout straw and see if the fan motor will start to run. Also, without power on the fan motor, does it have tight points when rotated by hand? It should take only the slightest of prodding to spin freely throughout several revolutions. If the fan does run when prodded (and the start/run capacitors are not bad - which it appears you have tried), but starts lethargically, it indicates that the bearing lubricants have deteriorated and/or the windings are compromised to the point of no return.

In my opinion, it is not the easiest of repairs, but well worth doing, to replace the original Dometic Penguin fan motor, in order to keep the original system and enjoy its long term reliability. In the past 15 years, Dometic has gone from one of the very highest reliabilities to one of the worst reliabilities in the industry, all based upon moving their manufacturing operations to China. I have no idea if it is lack of specification controls, lack of manufacturing controls or just planned obsolescence, but I have seen no indications that they are trying to change the downward trend.

The new replacement air conditioners have a number of unacceptable design and quality features (to me, at least). If they are manufactured in China (especially if by Dometic/Atwood, Coleman or Advent), industry experience is proving that they are most likely not going to be reliable over the long term (two years or more), they have taller profiles, they are incompatible with the currently installed CCC thermostats, their interior dimensions require bezels to hide previous AC installation marks and a several other (personal standards) incompatibilities. I'm keeping an open mind to these deficits, and I especially like the quieter operation of the new units, but most owners that have installed the newer units have just turned a blind eye to the China air conditioning manufacturing results and the ongoing reliability track record (or just chose to believe "It won't happen to me". Even to the point that our own FoFums won't answer the question "Where were their replacement units manufactured?".

A previous post of mine may be of some help to you:

Proactive AC Replacement?

HTH, Neal

Re: Dometic Penguin AC Compressor Question

Reply #4 – June 15, 2019, 10:32:29 am

Quote from: Neal Pillsbury – June 15, 2019, 09:45:28 am

...our own FoFums won't answer the question "Where were their replacement units manufactured?".

I answered the question: New Air Conditioners (Reply #12)

Re: Dometic Penguin AC Compressor Question

Reply #5 – June 15, 2019, 10:55:28 am

Quote from: Chuck & Jeannie – June 15, 2019, 10:32:29 am

I answered the question: New Air Conditioners (Reply #12)

Thank you Chuck,
I followed your installation and experience with much interest. I somehow missed that info - don't know why.

I've only seen two Atwood failures and one was indeterminate as to manufacture origin. The other was clearly China.

I haven't been able to find out anything through dealers or on-line that explains what now appears to be three different manufacturing locations. Hopefully it is a sign that Dometic is reacting to a poor experience in China and has moved (at least some) operations to Australia in seeking better reliability.

There are lots of us in this "old, leaky, Dometic Penguin boat" and it would sure be nice to have well defined options going forward.

Thanks again and keep us posted.

Neal

Re: Dometic Penguin AC Compressor Question

Reply #6 – June 15, 2019, 11:22:52 am

Quote from: Neal Pillsbury – June 15, 2019, 09:45:28 am

The new replacement air conditioners have a number of unacceptable design and quality features (to me, at least):
1. they have taller profiles
2. they are incompatible with the currently installed CCC thermostats
3. their interior dimensions require bezels to hide previous AC installation marks
4. several other (personal standards) incompatibilities.

Speaking only from my personal experience with one specific Atwood model, I would say:

1. This is certainly true - about 4" higher in my case. Standing outside the coach and viewing the roof with new, taller units, it looked somewhat "different" to me at first, but I soon became accustomed to the higher profile roof warts. Now I don't notice them. Aesthetic standards, of course, lie solely in the mind of the beholder. (See the quote in my signature)

2. We don't have CCC thermostats, so can't comment on this point.

3. Also true, in my case (non ducted units). The new interior panel is close, but misses covering the old shadow on the corners. We found the old black shadow could be removed by gently scrubbing the Ozite with carpet cleaner. We now cannot see any sign of the old shadow on our ceiling.

4. ?

Re: Dometic Penguin AC Compressor Question

Reply #7 – June 15, 2019, 11:38:25 am

Quote from: FourTravelers – June 15, 2019, 09:33:46 am

With those ohm readings on the running unit being about twice the resistance as the non op one, sounds like you have a short in the motor winding to me.
If it were just a locked rotor condition ( not good either) the readings should be similar. I am assuming the units are the same make and size, if not then disregard my comment as the readings could be quite different.

If it were me and I was headed to the desert southwest in the middle of the summer,??, I wouldn't trust it. Especially if we are talking about and older unit anyway.

The 260v reading is not unusual for a running motor (120v single phase) as it is basically a rotating auto transformer.

Both units on my coach are identical, they are ~2103 era Dometic Penguin II's, 13,500 BTU cooling only. In theory, I think I should be getting the same resistance readings for both motors, and like you say, believe the low resistance readings on the non-op compressor point to an internal failure.

I was very surprised by the 260v measurement, and honestly perplexed at how it is getting that voltage on the rear unit that functions properly.

I will say that I have scoured the net to try and find repair manuals for these Dometic units, and no such document exists.

Re: Dometic Penguin AC Compressor Question

Reply #8 – June 15, 2019, 11:49:45 am

By the way, and just an item of clarification for anyone that may be wondering, a CSA mark on a product (as on Chuck's new Atwood unit nameplate) indicates that a sample of the product has been certified to applicable standards written (or administered by) ANSI, UL, CSA, NSF International, and/or other North American organizations.

In short, the CSA marks and labels, applied by the manufacturer, prove that a sample product met certification requirements. In addition, the CSA mark can demonstrate that additional requirements – e.g., energy efficiency, sanitation, and low lead levels – have been met, as appropriate. It does not mean that the product was actually manufactured in either Canada or the US. It might have actually been manufactured in US, Canada, China, Australia or maybe Timbuktu.
HTH,
Neal

Re: Dometic Penguin AC Compressor Question

Reply #9 – June 15, 2019, 11:54:35 am

Quote from: Neal Pillsbury – June 15, 2019, 09:45:28 am

"evantwheeler",

You speak of the compressor "trying to start every 30-45 seconds or so", when I think that you are more likely referring to the AC unit fan motor. The compressor is hermetically sealed and does not try to start for two minutes, or more, AFTER the fan motor has started (if thermostat settings and refrigerant pressures are calling for compressor start).
I think that you are more likely experiencing a "tired" fan motor. The way to know for sure is to know the normal and then current inrush current amps when you call for the unit to start. You can measure that with an AC clamp on ammeter, from the AC breaker at the foot of the bed. A stuck rotor fan motor will show five to seven times higher starting current than running current, before the control board times out and trips off the start time cycle. Another easy way to verify is to gently prod either fan squirrel cage wheel with a dowel or stout straw and see if the fan motor will start to run. Also, without power on the fan motor, does it have tight points when rotated by hand? It should take only the slightest of prodding to spin freely throughout several revolutions. If the fan does run when prodded (and the start/run capacitors are not bad - which it appears you have tried), but starts lethargically, it indicates that the bearing lubricants have deteriorated and/or the windings are compromised to the point of no return.

In my opinion, it is not the easiest of repairs, but well worth doing, to replace the original Dometic Penguin fan motor, in order to keep the original system and enjoy its long term reliability. In the past 15 years, Dometic has gone from one of the very highest reliabilities to one of the worst reliabilities in the industry, all based upon moving their manufacturing operations to China. I have no idea if it is lack of specification controls, lack of manufacturing controls or just planned obsolescence, but I have seen no indications that they are trying to change the downward trend.

The new replacement air conditioners have a number of unacceptable design and quality features (to me, at least). If they are manufactured in China (especially if by Dometic/Atwood, Coleman or Advent), industry experience is proving that they are most likely not going to be reliable over the long term (two years or more), they have taller profiles, they are incompatible with the currently installed CCC thermostats, their interior dimensions require bezels to hide previous AC installation marks and a several other (personal standards) incompatibilities. I'm keeping an open mind to these deficits, and I especially like the quieter operation of the new units, but most owners that have installed the newer units have just turned a blind eye to the China air conditioning manufacturing results and the ongoing reliability track record (or just chose to believe "It won't happen to me". Even to the point that our own FoFums won't answer the question "Where were their replacement units manufactured?".

A previous post of mine may be of some help to you:

Proactive AC Replacement?

HTH, Neal

Neal, I saw your detailed post in that thread while searching this forum for answers last night. I had hoped you would see this and pop your head in.

The fan motor comes on instantly on a call for cooling, and it runs continuously on the unit with the non-op compressor. There are no issues with the fan motor that I can tell. I can adjust the speed settings and the fan motor reacts. I can spin the shaft freely while the fan is off and cover is off and there is no resistance that would point to something being wrong internally. The fan does not make any odd noise while running that would indicate an issue.

Regarding the compressor start frequency. Upon a call for cooling, the fan runs for about 20 or so seconds. The compressor then tries to start, bogging down the fan (audible difference, you can tell the fan is slowing down) and this "starting/bogging" draw lasts for 5 seconds. 20 seconds later, the compressor tries to start again, bogging down the fan. This repeats every 20 seconds.

I may have not have my terminology correct. The reason I say that the compressor tries to start is that I can hear a click, like a relay is closing, sending power to the compressor. I can hear a click at the compressor as well and you can hear a hum at the compressor like the motor is trying to start, but is locked up.

I concur with your thoughts on the quality of today's products. I'd gladly pay double the price for a higher quality unit that has a reasonable life expectancy and acceptable support. It appears that no such product exists for these rooftop mobile AC units. I had read through Chuck's thread on the Attwood units, and while they seem to be the better option to the Penguin II's I have on my roof due to noise, they are still not without their flaws. Someone had mentioned in another thread about a Dometic unit with some type of inverter compressor that is only available in Austrailia. It has the appearance and sleekness of the Penguin II, it's a shame Dometic can't bring a quality product to market given the number of RV's in this country.

Re: Dometic Penguin AC Compressor Question

Reply #10 – June 15, 2019, 12:05:14 pm

Do a Google search for Furrion RV A/C. Seems new the market with a screw type compressor. Let us know what you think as at least it is not owned by Dometic.

Re: Dometic Penguin AC Compressor Question

Reply #11 – June 15, 2019, 12:05:34 pm

Quote from: evantwheeler – June 15, 2019, 11:38:25 am

I will say that I have scoured the net to try and find repair manuals for these Dometic units, and no such document exists.

You can find all of the trouble shooting guides and service manuals you need and more at this website. Bryant RV Service. A library of rv information.
John M.

Service Documents and Manuals

Re: Dometic Penguin AC Compressor Question

Reply #12 – June 15, 2019, 12:19:31 pm

Quote from: John Morales – June 15, 2019, 12:05:34 pm

You can find all of the trouble shooting guides and service manuals you need and more at this website. Bryant RV Service. A library of rv information.
John M.

Service Documents and Manuals

I was on the website and missed the Duotherm service manual because I was looking specifically for a Penguin II manual. This is almost, exactly what I was searching for. Lots of good info in it, I wish it was model specific to my model, but will help me check a few additional items.

http://bryantrv.com/docs2/docs/acservice.pdf

Thanks!

Evan

Re: Dometic Penguin AC Compressor Question

Reply #13 – June 15, 2019, 12:41:04 pm

Quote from: Rudy – June 15, 2019, 12:05:14 pm

Do a Google search for Furrion RV A/C. Seems new the market with a screw type compressor. Let us know what you think as at least it is not owned by Dometic.

Thanks. I like the look of these unit and like the dual zone controllers. Everything seems reasonably priced. I hope that is not because it is garbage. Called the local RV center and they have some of these in some of their new lot models. Heading down to take a look today.

Downloads / Climate – furrion-global

Re: Dometic Penguin AC Compressor Question

Reply #14 – June 15, 2019, 12:45:07 pm

Quote from: evantwheeler – June 15, 2019, 11:54:35 am

..................Regarding the compressor start frequency. Upon a call for cooling, the fan runs for about 20 or so seconds. The compressor then tries to start, bogging down the fan (audible difference, you can tell the fan is slowing down) and this "starting/bogging" draw lasts for 5 seconds. 20 seconds later, the compressor tries to start again, bogging down the fan. This repeats every 20 seconds. .................

Evan,

Uh-Oh!! Once again, clamp on ammeter readings would be most helpful, BUT:

The advice I've gotten from the big Service Centers and the RV Mobile Techs at RiverBend (who have hundreds of failed AC unit history experiences) is that when the hermetically failed compressor and/or other components fail, inside the closed system, the best option is to bite the bullet and replace the entire AC, complete with all of the other implications.

That being said, some FoFum members have advocated surgery, replacement of the failed component and recharging of the sealed system. Those activities are beyond my pay grade, but I'd be very interested to know how it goes, if anyone tries to brave it.

HTH,
Neal

Re: Dometic Penguin AC Compressor Question

Reply #15 – June 15, 2019, 01:05:03 pm

I left two fully operational Penguin A/C units at Nacogdoches Motorhome Service just last month. I don't know what they did with them - didn't ask. I did tell them they were both working fine, and might be worth a few bucks on Craigs List. I wonder what would be involved in transplanting the complete sealed compressor (and associated plumbing) from one unit to another?

Re: Dometic Penguin AC Compressor Question

Reply #16 – June 15, 2019, 01:34:11 pm

Quote from: Chuck & Jeannie – June 15, 2019, 01:05:03 pm

I left two fully operational Penguin A/C units at Nacogdoches Motorhome Service just last month. I don't know what they did with them - didn't ask. I did tell them they were both working fine, and might be worth a few bucks on Craigs List. I wonder what would be involved in transplanting the complete sealed compressor (and associated plumbing) from one unit to another?

Likely not worth the effort/risk to swap out the compressor.

Re: Dometic Penguin AC Compressor Question

Reply #17 – June 15, 2019, 01:38:34 pm

A Hail Mary type thing....but you could possibly make it run with a hard start kit. I've had good luck with them for compressors reluctant to start, some lasted for years. Might work, or might be a waste of twenty five bucks.

That Furrion looks pretty good at first glance, no start capacitor and dual fans which are going to make it much quieter. Be nice to see one run in person.

Re: Dometic Penguin AC Compressor Question

Reply #18 – June 15, 2019, 01:47:03 pm

Quote from: Chuck & Jeannie – June 15, 2019, 01:05:03 pm

...........I wonder what would be involved in transplanting the complete sealed compressor (and associated plumbing) from one unit to another?...............

That would be a LOT of work, Chuck,

I had to remove the tinwork/shroud for one Fan Wheel (Condenser end, opposite the Evaporator End cooling fins and fan wheel) and then the entire motor/shaft/dual fan wheel assembly in order to replace my fan motor and shaft.

Most shops wouldn't want to fuss with that. It took me about 4 hours and it was an "iffy" proposition, regarding whether I could get the fan wheels off of the shaft with the tools that I had at hand. My work was all done on the roof top and I didn't have to separate the DuoTherm from the rooftop. Dometic shop rate is 1.5 hrs to accomplish same — that's either unrealistically optimistic or they use specialized tools that go well beyond a very complete set of SnapOn that I have.

If one were to remove and replace the the ENTIRE evaporator coil/fins/condenser coil/fins/compressor assembly, that would be much more difficult. I either didn't look at or don't recall how the coils and compressor frames are attached to the overall AC baseplate and framework.

I too like the looks of the Furrion design and company. They seem to be motivated by a Quality/Reliability design and manufacturing solution to a recreation industry deficit, rather than being motivated by mass production greed. There isn't ANYTHING negative to be found on line, at least that I have found.

HTH,
Neal

Re: Dometic Penguin AC Compressor Question

Reply #19 – June 15, 2019, 02:13:46 pm

Quote from: Chuck Pearson – June 15, 2019, 01:38:34 pm

A Hail Mary type thing....but you could possibly make it run with a hard start kit. I've had good luck with them for compressors reluctant to start, some lasted for years. Might work, or might be a waste of twenty five bucks.

That Furrion looks pretty good at first glance, no start capacitor and dual fans which are going to make it much quieter. Be nice to see one run in person.

Thanks Chuck. I installed a brand new hard start kit (3311883.000 - Hard Start Kit for Penguin Models) last night to no avail.

Re: Dometic Penguin AC Compressor Question

Reply #20 – June 15, 2019, 02:16:40 pm

That's a odd deal: I had them on the Airstream and they worked great! Never even heard of a 'hard start kit', sounds strange.

Re: Dometic Penguin AC Compressor Question

Reply #21 – June 15, 2019, 02:49:20 pm

I wanted to be able to run one ac on a dedicated 20 amp circuit, or a honda eu2000, so got a micro air easy start.
EasyStart 364 (3-ton) Single Phase Soft Starter for Air Conditioners –...
Not sure of the long term effect on the ac, but have been running it pretty well full time, for two years on either ac or heat pump with no noticable changes in performance.
Not sure how it works, but amperage, measured with amprobe, gradually ramps ups and never exceeds 15 amps. Time will only tell if it reduces ac life.
Both ac's on coach are 15 years old.

Re: Dometic Penguin AC Compressor Question

Reply #22 – June 16, 2019, 06:19:08 pm

Ok, so the local dealer for the Furrion units had none in stock, none on any RVs in the lot, and can't find record of having sold one. I am going to hold off on replacing everything new in hopes that I can find a like kind used replacement to limp me along for a while. I've installed reflective bubble wrap over all windows and it has drastically reduced my heat gain such that the single AC keeps the interior comfortable enough in 90-100F outside temps. I will just have to plan my trip to drive at night as there is no chance it will be comfortable driving through the CA & NV desert at over 100F with just the single rear AC (we saw 120F in Moapa, NV during the middle of the day!).

Re: Dometic Penguin AC Compressor Question

Reply #23 – June 16, 2019, 08:11:12 pm

My suggestion is to close ALL of the vents, leaving the two forward vents pointing towards the front. Would probably also benefit from a forward-facing fan about where your end table is. I plan to also install a pair of 12 volt fans above the dash, facing the two cockpit seats.

Good luck.

Trent

PS: It is amazing how much air you can get up front if you open the driver and passenger windows a little bit; noisy, though.

Re: Dometic Penguin AC Compressor Question

Reply #24 – June 16, 2019, 08:22:24 pm

Etrailer sells the Furion AC's. Looking at the videos and documentation they will work directly with our Dometic thermostat. They have a separate plug connection that plugs in directly to the Dometic connections. I'm very interested in these units because of the Dometic integration. The prices are very reasonable.
John M.

Furrion Chill Rooftop RV Air Conditioner - 14,500 Btu - White Furrion RV Air...

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