[rcantrell52]

All, 
Newell started construction on our 08 in 2006. How long will the roof air conditioners last or when should they be replaced? In June 2018 I took the coach to Newell for it's yearly PM. During the PM the air conditioners had their amps measured while in use. When in use A/C #1 and 2 were using between 10-11 amps each and A/C #3 and 4 were using approximately 9 amps each. At what point do I need to replace A/Cs #1 and 2? Will I throw a breaker if 50 amps is exceeded?
Any and all comments is appreciated.

Reese Cantrell
Newell Coach 1242

[encantotom]

they are so easy to change that i would just wait until one fails. remember 50amps is on each leg. and you have 2 air conditioners on each leg. so you are only at roughly 20amps on each leg with all 4 running. the difference between 9 and 10 amps is negligible in my eyes. difference between meters and eyeballs and the actual draw of the compressor and fan.

those air conditioners can last a long time. ask clarke. he has the originals in his 82.

my two cents worth.

tom

[Fulltiming]

I haven't done routine load testing on air conditioner units but back in the day when I had roof airs, I found that if they were exercised regularly, it was not uncommon to get 15-20 years out of a roof air. On the other hand, I have had to replace one that was only about 6 years old.

You will throw a breaker if the 120 volt leg the AC unit is wired into exceeds about 50 amps. You should have 2 AC units on Leg 1 and the other 2 on Leg 2 so you likely have about 20 amps on each leg currently when all four are on. The ammeters on your coach are your friends. Your battery chargers, dishwasher, electric cooktop, microwave and electric dryer can add significant loads if they are in use. Additionally, the use of a hair dryer can take 12+ amps on whichever leg it is on.

[rcantrell52]

Tom and Michael,
Thank you for this information.

Reese Cantrell
Newell Coach 1242

[folivier]

I've found that the best practice is to either keep it running or exercise it frequently. The capacitors can go bad and the fan motor bearings or bushings should be kept moving. And a yearly cleaning of the coils and mud dubbers is a good idea also.

[whatsnewell]

My two original Duotherms are 37 years old and still blowing ice cubes. If the outside temp is under 100 can only run one at a time or it gets too cold. Rear A/C draws 11-12 amps, and front draws 10 amps.

[Richard]

As stated earlier, replace when they fail. Older is better! Following other RV forums there seems to be a trend that the roof airs made in the last three or four years are not as reliable as those of previous eras. I can’t quantify that, just my perception.

[rcantrell52]

Forest, Clarke, and Richard,
Thank you for your insight.


Reese Cantrell
Newell Coach 1242

[NotSoFast]

Reese,

I have a similar 2008 dated coach (1223)

When I purchased my coach about 1.5 years ago the factory needed to replace the number 2 A/C unit. The number 3 unit also needed to be replaced but the factory missed that when checking it over. I had it replaced once I got home. Last summer the number 1 unit went bad and was replaced in Oregon. The 2 units I personally dealt with had problems that did not show a high amperage reading. I found the problems using a temperature gauge in the outlet. I believe the problem was related to the valve that handles the heat pump switch-over, apparently they can stick and keep the unit from cooling properly. All of the new units are Coleman Mach 8 and show 12 to 13 amps when running which is about the same as the one remaining original unit (#4).

I would not replace the units if they still cool and are drawing 11 to 12 amps. They could last quite a bit longer. Get some kind of temp gauge (I use an IR gun) and watch the temp on the outlets and the amp draw. It will be apparent when the unit has failed.

[rcantrell52]

Not,
I will check the temperature. Thank you for your comments.

Reese Cantrell
Newell Coach 1242