Running A/C

[Grip]

If you have only a 15amp breaker circuit don’t use the ac. First there is an adapter dog bone…quality?
Then an extension cord… correct one? The prongs of the adapters dog bone is a 20amp design. Make sure the extension cord is proper gauge.
Long term use WILL cause arcing burns on the prongs that will then cause increased resistance.
Then there is the chance that your not just running the ac. Don’t under power your ac your asking for trouble..burn out your ac electrical stuff.
Get a 30 amp circuit installed or get a proper generator.

[mrpavette]

I wouldn’t put anything less than a 20 amp circuit breaker with 12 gauge wire. If the CB breaker kicks when the A/C kicks on you might need a special CB to absorb the initial surge. Went I replaced my in house vacuum. It would occasionally kick the CB during start up. I contacted SQ D and their engineer told me what CB to use. Had to order off the internet. Elect supply houses didn’t carry it or know about it.

[RKHengst]

Originally Posted by 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

I often run our smaller AC (13.5btu) with a standard 20amp house outlet. I do use the heavy 50amp cord and use just 1 dogbone to plug into the outlet. I used to go back and check the cord periodically, but it has never even been warm, even after extended use. I did double check to make sure no other heavy duty appliance is on that circuit.

[Jim in Pa]

Originally Posted by Grumpy

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

you could melt your plug or adapter

[Grumpy]

Originally Posted by Jim in Pa

you could melt your plug or adapter

Unlikely.. it would melt using any power source then, the current DRAW is always the same. Heat is based on the load, not what is providing the current.

[Vicr]

Originally Posted by Jim in Pa

you could melt your plug or adapter

How would a 13 amp load melt an adapter rated for 20 amps??

[Vicr]

Originally Posted by mrpavette

I wouldn’t put anything less than a 20 amp circuit breaker with 12 gauge wire. If the CB breaker kicks when the A/C kicks on you might need a special CB to absorb the initial surge. Went I replaced my in house vacuum. It would occasionally kick the CB during start up. I contacted SQ D and their engineer told me what CB to use. Had to order off the internet. Elect supply houses didn’t carry it or know about it.

They are called HACR breakers.


HACR stands for Heating, Air-Conditioning, and Refrigeration breaker. HACR rated breakers open within a specified time curve, similar to a fuse, to protect group motor equipment (fans for combustion air, exhaust control, heated air handling, AC compressors, etc).

[internalvoice]

Generally speaking you are limited to about 80% of the circuit interrupters labeled capacity. For a 15A breaker this is 12A or 1440Watts. This is why you never see an appliance that plugs into a 15A receptacle with a higher power requirement than 1500W.
This is due to design and also how thermal magnetic interrupters work. Since heat generated in a bimetallic strip is what causes them to open, they have what is known as a "trip curve" this is a relationship between current draw, and time at a given ambient temperature. It s not linear and in fact more similar to an inverse logarithmic curve. When you just enter the trip curve (generally above 80%) you could operate for hours, or minutes depending on the curve characteristics. Eventually the heat will build up enough to open the contacts. The more current you draw the quicker the contacts will open. There is a possibility the AC will work, since it wont run at 100% duty cycle. It will cycle on and off, likely providing time for the breaker to cool and not tip. Your best bet would be to check the nameplate on the AC and see what its current draw is. It its under 12A you are good, but likely don't expect to run too much more. If you do need the extra power, you could run a heavy 12GA extension cord from a 20A kitchen counter receptacle and use a 15-30A adapter built with 12GA or larger cable. the contacts on a 15A plug will handle the current since they are the same as on a 20A just oriented differently, just make sure the cord is short enough to not cause voltage drop and conductor heating.

[internalvoice]

Originally Posted by Vicr

They are called HACR breakers.


HACR stands for Heating, Air-Conditioning, and Refrigeration breaker. HACR rated breakers open within a specified time curve, similar to a fuse, to protect group motor equipment (fans for combustion air, exhaust control, heated air handling, AC compressors, etc).

Also known as high magnetic and often found on lighting circuits with many inductive ballasts. They typically differentiate the part numbers from the standard trip curve with an added "H"

[RPR]

More info

[Bill Johnson]

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?

I was up at Lake puckaway this week fishing and one of the campground guys was telling me they have a 120 volt plug with 40 amps and the wiring meets code. I don't think I'll be bringing my motorhome up there, they have one seasonal spot I could park if the ground isn't too wet at the time

[RPR]

May be 50 amp rated 120 looking receptacles

[Bill Johnson]

Originally Posted by RPR

May be 50 amp rated 120 looking receptacles

I told him I had a 50 amp plug and drew him a diagram of 50 amp and 30 amp he said I would need an adapter to a regular 120 house outlet. Before the owner told me there was nowhere to park and that I would need to boondock. I asked if there was a dump station and they said you can dump it in my farm field. This place is from the early 1950s. I guess I'll just stay in a cabin that is the same from 1954. It's just ruff staying with a chain smoker for a week. I feel like burning my clothes when I get home. I think I lose 2 weeks off my life every time I go