Running A/C

[Highlander73]

When we have our TT home and we are plugged in to shore power can we run the AC! The TT is 30amp and we only have 15 amp outlets. Living in AZ during summer makes running the AC almost a must if we are going to be in the rig for any length of time. I’m looking into having an 30amp outlet installed but in the short term can we Run the AC?

[Grumpy]

Originally Posted by Highlander73

When we have our TT home and we are plugged in to shore power can we run the AC! The TT is 30amp and we only have 15 amp outlets. Living in AZ during summer makes running the AC almost a must if we are going to be in the rig for any length of time. I’m looking into having an 30amp outlet installed but in the short term can we Run the AC?

Plug it in and try. Worst case scenario the breaker in the house will pop.

[Route 66 Traveler]

What size is the AC....13.5K or 15k? The starting current most likely will trip the breaker. Once running my 15k runs uses 12 & 14 amps.

If you connected it to a 20 amp outlet and installed a SoftStart it would run all day without a problem.

https://www.softstartrv.com//rvlife/?utm_CamperReport

[Jagiven]

Yes and No, I have done it many times. But I have never let the AC run for any extended time as I noticed my cheap 15 amp to 30 amp adaptor would get very warm after a few hours. Strongly recommend using a 12 gauge extension cord (if needed) and a quality 15 amp to 30 amp dogbone.

I never tripped a breaker.

[mini4mw]

I've run my 13.5BTU AC on a 15amp and it usually won't trip a breaker. There are other lights and such on the same breaker so if someone turns something on its close enough to trip.

I would agree with the others that I would not run it a long time continuously. Depending on wiring, dog bone (30amp to 15amp) and other things it may get hot and damage wiring which could lead to a short and other issues.

If you wanted to run it to keep it cool, install a 50amp plug (if you can afford the extra cost from 30amp) and then dog bone 50 to 30amp. This way if you ever need a 50amp (new RV ) its there.

[mokurt]

Mine won't work with 15 amp

[RedHorse1]

We ran our X23B AC successfully on a 20A circuit but it would trip a 15A breaker. There were a couple of handy 15A outlets but the 20A was in the kitchen and required running the cord thru the kitchen window, only 2-3 hrs at a time while packing, cleaning or maintenance. I used the connected 30A power cord and a 30A extension to a 30-15A dogbone, no “shop” extension cord.
A soft-start cap on the AC might have made a difference but can’t say for sure.

[VKC]

It also depends what other plugs are on that circuit.

[Vicr]

I'm an electrician who has done exactly what the OP wants to do.

Using the shortest length (under 50' would be best and NOT ANY of it coiled) 12 gauge extension cord plugged into a 20 amp circuit with an adapter, with no other loads on the circuit, and a Fluke model 325 clamp meter on the circuit wire at the breaker my 13K air conditioner with no soft StartStart ran just fine for hours pulling a full load of 13 continuous amps with no heat anywhere in the supply system.

So OP yes you can on a 20 amp circuit if you have one available.

[RPR]

My former next door neighbor spec out commercial electrical blue prints for a living and told me that a breaker would not handle its rated amperage under continuous draw. Wire would handle its rated amperage all day long.

[Scott91370]

I do it quite often. Do not use an extension cord unless it it can handle the power draw.

[us71na]

I've run my A/C several times for several days from 20 amp house circuits with no breaker trips. The A/C is on a 20 amp breaker in the trailer. I use the installed trailer 30 amp power cord with an adapter to the household receptacle.

[Vicr]

Originally Posted by RPR

My former next door neighbor spec out commercial electrical blue prints for a living and told me that a breaker would not handle its rated amperage under continuous draw. Wire would handle its rated amperage all day long.

This is why electricians prove electrical engineers wrong quite often. Most of the multi-million dollar electrical projects I do have dozens of RFI's (request for information) sent to electrical engineers because they either make mistakes, the engineering will cost $$$$$$ more than a more simple installation or the engineering isn't complete.

Circuit breakers are tested not only by their manufacturer but by UL Laboratories to ensure that electrical products perform to the specification they are designed to do.

I would suspect that your former next door neighbor was no engineer and had no real field experience in electrical installations.

[craigav]

Originally Posted by Vicr

This is why electricians prove electrical engineers wrong quite often. Most of the multi-million dollar electrical projects I do have dozens of RFI's (request for information) sent to electrical engineers because they either make mistakes, the engineering will cost $$$$$$ more than a more simple installation or the engineering isn't complete.

Circuit breakers are tested not only by their manufacturer but by UL Laboratories to ensure that electrical products perform to the specification they are designed to do.

I would suspect that your former next door neighbor was no engineer and had no real field experience in electrical installations.

Are you saying that a standard household circuit breaker will allow for a 100% "continuous" load of its amp rating?

[Jagiven]

Originally Posted by craigav

Are you saying that a standard household circuit breaker will allow for a 100% "continuous" load of its amp rating?

Per the NEC codes; Yes if the breaker was designed for "operation at 100%". Not all breakers are made the same.

As standard breaker is designed to run at 80% capacity

[craigav]

Originally Posted by Jagiven

Per the NEC codes; Yes if the breaker was designed for "operation at 100%". Not all breakers are made the same.

As standard breaker is designed to run at 80% capacity

Yes indeed, that is where I was going with my comment. I have never seen a standard household breaker listed for 100% continuous duty, therefore the 125% NEC rule is that the continuous protection rating states that the circuit is to be protected at 125% of the continuous load (I would have to lookup the exact verbiage) which means that if you are going to pull 16a continuous you need a 20a breaker, and the inverse of that is 80% which means a 20a breaker should not exceed a 16a continuous load and while temperatures come into play, most common household (and rv) breakers will trip at just above 80% of their rating if the current is continuous, (continuous is defined as a constant current over 3 hours). The same can be said for a 15a circuit in a house protected by a 15a breaker, you can expect it to trip when the current exceeds 12 amps for more than 3 hours and can handle the full 15a (and even more for a short time such as when an a/c starts) with a non-continuous load. Therefore, if you have an A/C that pulls 13~14 amps and you plug it into a household circuit protected at 15 amps, it is just a matter of time until the breaker will trip if the load remains a continuous load. ~CA

[RPR]

Endurance

[mrmom]

First thing I did was add a 30 amp circuit for my rig. Mine was easy, the breaker panel in on an exterior garage wall right next to where my camper sits. All you need is a 30 amp breaker, some 10 ga. wire and a weatherproof outlet for the side of the house. My recommendation would be to install the circuit asap and not have to worry about all the rest! Besides, it's great to keep the battery charged and the fridge cold between trips not to mention running the ac while packing on a 90 degree day!

[VKC]

I’m with you.

[Camper_bob]

Originally Posted by mrmom

First thing I did was add a 30 amp circuit for my rig. Mine was easy, the breaker panel in on an exterior garage wall right next to where my camper sits. All you need is a 30 amp breaker, some 10 ga. wire and a weatherproof outlet for the side of the house. My recommendation would be to install the circuit asap and not have to worry about all the rest! Besides, it's great to keep the battery charged and the fridge cold between trips not to mention running the ac while packing on a 90 degree day!

+1

I actually had a 50A RV outlet installed before I ever even brought my first TT home. Had it installed by an electrician I know and trust. And I've NEVER regretted that for even a second. My layout is just like mrmom's, so there was no expensive wire run. Just a breaker-protected outlet coming right off my main service panel outside the garage.

Right now my MH (30A) is sitting in my driveway, fully functional, while some remodeling is done on my home.