Replacing rear 13,500btu with 15,000btu A/C?

The 15K pulls about 1.5 to 2 amps MORE than the 13.5k. Regardless of what you have done in the past, running a 15k and a 13.5k is NOT advisable on 30 amp service. The 15k pulls about 14 amps and the 13.5k about 12 amps. That puts you at 26 amps BEFORE you add in the refer(2.5 amps) and the Power Converter (1 to 2 amps) and any other 120 appliance(coffee maker/ kitchen cooking appliances/ ANYTHING else that needs 120 power. While you have done it, I will bet the 50 to 30 adapter, the 30 amp pins show heat and wear. Doug

That is good to know, as I did not realize that.

I wouldn't bother to swap them out if it's just to upgrade but if you are replacing anyway the cost difference should be small, so sure.

As mentioned, two on 30amp is questionable regardless of BTU rating.

The 30amp outlet is actually only rated at 25amp continuous, so while it may or may work, there is a good chance of overheating wires and connections. In a worst case scenario, it could lead to a fire if the breaker doesn't trip.

If you are running both the front and rear, does the coach stay cool? If so, stay with what you have. If I ran both 13.5s in my Sahara, you could store meat. I usually leave the rear off at night to cut down on the noise and use a fan to blow air in from the front.

Currently, not cool enough to our liking. The front was struggling last year. Both units are 14 years old.

Check out the noize level before you purchase. My Atwood Air Commander is VERY quiet compared to the old unit.

Does your unit have an EMS that manages electrical usage? If so, let it do it’s job and run them both. IF not, I would not try running both at once on 30. If it were mine, and I stayed mostly where there is 50 amp service I’d get two 15’s and deal with the 30 amp sites as needed.

Depending on the make, Model (of both) and the age of your current A/C there may be absolutly NO cons. Save a bit more weight.

My story

Rv Came with twin Carrier Air V's 13,500 BTU 13.5 Amps running
First replacement was with an Advent Air (I DO NOT RECOMMEND) 15,000 btu's 13.5 Amps Though the running amps are the same the starting is higher. My Power systems "Feel" it more when it kicks in. more on this in a bit including why I do not recommend this made in china system.

The other one was replaced with a Coleman.. 15,000 btu 13.9 Amps. yes not quite 1/2 amp more draw, but not as hard starting.

Turns out Coleman's "Suck" (Draw air in via the condenser) most other makes, Advent included "Blow" (Push air out through the condenser.

That's unless you replace the Advent Fan (Which being a CHina Bomnb blew up on me) With a coleman fan, now it sucks

Both systems you can (in theory) get an "Adapt-a-kit" to use the original carrier controls.. Sadly not avabial when I put in the Coleman so it's local.

Now the reaons I don't recommend Advent
For "Blowers" to clean the cottonwood cotton off you have to remove the outer cover, then the inner cover.. On my Carriers this inner cover covered JUST the condenser and was a few screws.. On the advent it's a single cover for both ends (I only opened half of it and bent it in the middle) and held on with tabs and tape.. Major pain and you can only bend those tabs so many times before they break.

Thankfully it now has a coleman fan so it's a sucker

Suckers you remove the outer coverm peal off the cottonm put the cover back on job done, .

valhalla360 wrote:
I wouldn't bother to swap them out if it's just to upgrade but if you are replacing anyway the cost difference should be small, so sure.

As mentioned, two on 30amp is questionable regardless of BTU rating.

The 30amp outlet is actually only rated at 25amp continuous, so while it may or may work, there is a good chance of overheating wires and connections. In a worst case scenario, it could lead to a fire if the breaker doesn't trip.

Please reference any codes or NEC your statement that an RV 30 amp PLUG and 30 POWER CORD is only rated at 25 amp continuous. We are talking RV wiring, not regular home circuits. They have designed 30 amp RV's for over 45 years and in 38 years as a tech, I have NEVER heard the 25 continuous running as it applies to RV's. I have seen and heard it on various forums, but NEVER from an expert, just posters that heard of this from other sources. Doug

Look into an autoformer to support the voltage. Sola Basic has 8000 VA units

I can safely run my roof air on a 97 volt shore power supply.